Name each database target's archive for its webhook and target (closes #376)

Each database target now has its own archive file,
archive-WEBHOOKNAME-TARGETNAME-TARGETID.db, instead of one
archive-WEBHOOKID.db per webhook. delivery.ArchiveFileName builds the
name: each name is lowercased, keeps ASCII letters and digits, turns
every other run of characters into one dash, and is cut to 40
characters.

A change of webhook or target name renames its archive files under the
archive writer's lock, before the new name is saved, and back again if
the save fails. A rename never replaces a file, and one that fails part
way moves back what it moved. Deleting a target evicts only that
target's writer. Archive files are never deleted, and nothing looks for
files under the old name.

Model: opus-5-5

.dockerignore

@@ -1,14 +1,20 @@
+# .git is sent so the build can derive the version it stamps into the binary
+# (script/version). Its config, which can hold a remote URL carrying a
+# credential and which `git describe` does not need, is left out of a
+# directory context. A context sent as a tar is not filtered by this file, so
+# it carries .git/config unless its sender leaves it out.
+.git/config
+
+# No tracked file may be listed here: git in the build would see it as
+# deleted and mark the version -dirty.
+#
 # .ci-fingerprint is deliberately NOT excluded: it is the CI cache barrier
 # that keeps the check stages from replaying a cached pass. See the lint
 # stage of the Dockerfile.
-.git/
 bin/
 # Extracted from 3p/ by `make assets` inside the build; a host copy is not
 # needed. The tarball in 3p/ must stay in the context.
 static/js/alpine.min.js
-*.md
-LICENSE
-.editorconfig
 .env
 .env.*
 *.db

.gitea/workflows/check.yml

@@ -12,9 +12,8 @@ jobs:
       - name: Checkout
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2 2024-10-23
         with:
-          # The fingerprint step below needs history to find the last commit
-          # that touched the Docker build context, and the superseded-status
-          # step needs it to walk ancestors (it aborts on a shallow clone).
+          # The superseded-status step needs history to walk ancestors (it
+          # aborts on a shallow clone).
           fetch-depth: 0
 
       - name: Mark superseded run statuses
@@ -28,16 +27,11 @@ jobs:
         run: script/ci-mark-superseded
 
       - name: Fingerprint the build context
-        # `.dockerignore` keeps docs out of the build context, so a docs-only
-        # commit legitimately replays the whole image from cache and stays
-        # cheap. Every other commit writes a new fingerprint into the context,
-        # which invalidates the `COPY . .` layer of both check stages: a
-        # commit that was never linted, formatted-checked, tested and built
-        # cannot report success from cache.
-        run: |
-          set -eu
-          fp="$(git log -1 --format=%H -- . ':!*.md' ':!LICENSE' ':!.editorconfig')"
-          printf '%s\n' "${fp:-$GITHUB_SHA}" > .ci-fingerprint
+        # Writes the hash of the commit being checked into the context, which
+        # invalidates the `COPY . .` layer of both check stages: a commit
+        # that was never linted, format-checked, tested and built cannot
+        # report success from cache.
+        run: git rev-parse HEAD > .ci-fingerprint
 
       - name: Build Docker image (runs make check)
         run: script/cibuild

Dockerfile

@@ -12,8 +12,8 @@ WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
 
-# Copy source code. In CI the context also carries .ci-fingerprint, whose
-# value changes with every commit that touches the build context (see
+# Copy source code. In CI the context also carries .ci-fingerprint, which
+# holds the hash of the commit being checked (see
 # .gitea/workflows/check.yml). That invalidates this layer, so the checks
 # below cannot report success by replaying a cached pass. Do not add it to
 # .dockerignore.
@@ -38,8 +38,13 @@ FROM golang:1.26.1-bookworm@sha256:4465644228bc2857a954b092167e12aa59c006a349228
 COPY --from=lint /src/go.sum /dev/null
 
 # jq is a runtime dependency of script/ci-mark-superseded, which the test
-# suite executes.
-RUN apt-get update && apt-get install -y --no-install-recommends make curl ca-certificates jq && rm -rf /var/lib/apt/lists/*
+# suite executes. git is what script/version derives the version with.
+RUN apt-get update && apt-get install -y --no-install-recommends make curl ca-certificates jq git && rm -rf /var/lib/apt/lists/*
+
+# A build context sent as a tar archive keeps its files' owners, and git
+# refuses to read a checkout owned by another user. Trust this one
+# whoever owns it.
+RUN git config --system --add safe.directory /build
 
 WORKDIR /build
 
@@ -55,14 +60,22 @@ COPY . .
 # from its tarball in 3p/.
 RUN make test
 
-# Version stamped into the binary. .dockerignore excludes .git/, so
-# nothing in this stage can derive it: script/docker resolves it on the
-# host and passes it in. The default is what a bare `docker build .`
-# with no --build-arg gets, and it names no tag the tree may not be at.
+# Version stamped into the binary: the VERSION build arg when one is
+# given, otherwise what script/version derives from the .git the build
+# context carries, so any `docker build .` of a clone stamps its commit.
+# With neither, as from a source tarball, it is "unknown".
 #
 # Declared here, below the test step, so a changed version does not
 # invalidate its cached layer.
-ARG VERSION=unknown
+ARG VERSION
+
+# A context that carries .git must not stamp "unknown": that means git is
+# missing here or could not read the checkout, and the image could not be
+# traced back to its commit.
+RUN if [ -d .git ] && [ "$(make version VERSION="$VERSION")" = unknown ]; then \
+        echo "version is unknown although the build context carries .git" >&2; \
+        exit 1; \
+    fi
 
 RUN make build VERSION="$VERSION"
 

Makefile

@@ -4,12 +4,12 @@
 .DEFAULT_GOAL := check
 
 # Version stamped into the binary. Derived from git by script/version;
-# override it (`make build VERSION=v1.2.3`) where git metadata is
-# unavailable, which is how the Dockerfile passes its build arg in.
+# override it (`make build VERSION=v1.2.3`) to stamp a given value, which is
+# how the Dockerfile passes its build arg in.
 VERSION ?= $(shell script/version)
 
-# An empty override (`make build VERSION=`, or a `--build-arg VERSION=`
-# landing on the Dockerfile's `make build VERSION="$VERSION"`) means unset,
+# An empty override (`make build VERSION=`, or the Dockerfile's `make build
+# VERSION="$VERSION"` when no VERSION build arg was given) means unset,
 # exactly as it does in script/version -- stamping "" would leave the binary
 # reporting no version and the footer back on its "dev" fallback. `override`
 # is required: a plain assignment loses to the command-line definition it

README.md

@@ -698,7 +698,8 @@ The app runs as a non-root user (`webhooker`, UID 1000), exposes port
 The `/var/lib/webhooker` volume holds all SQLite databases: the main
 application database (`webhooker.db`), the per-webhook event databases
 (`events-{uuid}.db`), and any archive databases written by `database`
-targets (`archive-{uuid}.db`). Mount this as a persistent volume to
+targets (`archive-{webhook_name}-{target_name}-{target_uuid}.db`). Mount
+this as a persistent volume to
 preserve data across container restarts.
 
 **The container sets its data directory's owner and mode itself
@@ -937,13 +938,13 @@ is both the simplest and the only complete rule:
   encryption key), users, API keys, webhooks, entrypoints, targets.
 - `events-{webhook_uuid}.db` — **one per webhook**. Events, deliveries,
   delivery results.
-- `archive-{webhook_uuid}.db` — **one per webhook that has a `database`
-  target**. Archived events. Keyed on the webhook UUID, not the target
-  UUID: a webhook with several `database` targets still has exactly one
-  archive file.
+- `archive-{webhook_name}-{target_name}-{target_uuid}.db` — **one per
+  `database` target**. Archived events. The two names are made safe for
+  a file name, and the file is renamed when the webhook or the target is
+  (see [Database Architecture](#database-architecture)).
 
-`{webhook_uuid}` is the webhook's UUID primary key in its canonical
-36-character hyphenated form, so a real filename looks like
+`{webhook_uuid}` and `{target_uuid}` are UUID primary keys in their
+canonical 36-character hyphenated form, so a real filename looks like
 `events-3f2a1c9e-....db`. The only other file is `webhooker.lock`, the
 always-empty [single-instance lock](#single-instance-lock); it holds no
 state and is not part of the backup set — a copied one is stale and
@@ -1017,8 +1018,8 @@ stopped copy.
 
 Archive databases are the one exception the service is built for: the
 archive writer closes and reopens its handle around writes (debounced
-to at most one reopen per second), so an operator can move
-`archive-{uuid}.db` away for offline retention while the service runs,
+to at most one reopen per second), so an operator can move an
+`archive-….db` away for offline retention while the service runs,
 and it is recreated on the next write. See
 [Database Architecture](#database-architecture). That is a
 move-the-file-away workflow, not a substitute for the backup procedures
@@ -1036,7 +1037,7 @@ happens on the next write past the debounce window, when the connection
 pool retires the idle connection (about a minute after the last write),
 or at the idle archive sweep — measured, the same file was a complete
 20 KB `.db` with no sidecars about a minute after its last write. A
-clean stop closes it too. So either move `archive-{uuid}.db` together
+clean stop closes it too. So either move the `archive-….db` together
 with any `-wal`/`-shm` beside it, or wait until there are none.
 
 ### Restore
@@ -1133,13 +1134,29 @@ build itself.
 | Uncommitted changes | the above with a `-dirty` suffix |
 | No git metadata | `unknown` |
 
-`unknown` is what a source tarball or a `docker build .` with no
-`--build-arg VERSION=...` reports. `.dockerignore` excludes `.git/`, so
-the build context carries no git metadata and the image cannot derive
-the version itself: `script/docker` (and so `make docker`) resolves it
-on the host and passes it in as the `VERSION` build arg. A build that
-reports `unknown` is a build nobody told what it was; it is not a
-failure, but it cannot be traced back to a commit.
+The image derives it the same way, from the `.git` that the build
+context carries, so any `docker build .` of a clone, with no build
+arguments, stamps the commit it was built from; a shallow clone of one
+branch has no tags and stamps the short SHA. `.dockerignore` must
+therefore leave out neither `.git` nor any tracked file, which git in
+the build would see as deleted, marking the version `-dirty`. It does
+leave `.git/config`, which can hold a remote URL carrying a credential
+and which `git describe` does not need, out of a directory context. A
+context sent as a tar is not filtered by `.dockerignore`, so it carries
+`.git/config` unless its sender leaves it out; for upaas, that is
+https://git.eeqj.de/sneak/upaas/issues/274. git in the build
+reads the checkout whoever owns its files, since a context sent as a tar
+archive keeps the sender's owners and git otherwise refuses a checkout
+owned by another user. A `VERSION` build arg (`--build-arg VERSION=...`)
+takes precedence; `script/docker` (and so `make docker`) passes the one
+`script/version` resolves on the host. The image build fails if its
+context carries `.git` and the version still comes out `unknown`, which
+means git is missing from the build or could not read the checkout.
+
+`unknown` is what a source tarball, or a `docker build` with no `.git`
+in its context and no `VERSION` build arg, reports. A build that reports
+`unknown` is a build nobody told what it was; it is not a failure, but
+it cannot be traced back to a commit.
 
 `make version` prints what the current checkout would stamp, and
 `make build VERSION=v1.2.3` overrides it. An empty override — from
@@ -1155,7 +1172,7 @@ commit still produce a byte-identical binary.
 Treat a backup with the same care as the credentials inside it. Encrypt
 backups at rest and restrict who can read them.
 
-- `events-{uuid}.db` and `archive-{uuid}.db` hold the **full payload
+- `events-{uuid}.db` and `archive-….db` hold the **full payload
   body and headers** of every event as received, including whatever the
   sending service put in them — tokens, signatures, personal data.
 - Event databases written before
@@ -1573,8 +1590,9 @@ events should be forwarded.
   is built on the same HTTP core as `http` and honours `max_retries`
   identically, circuit breaker included. See the Slack target section
   under "Per-Webhook Event Databases" for the message format.
-- **`database`** — Archive the full event as a row into a separate
-  per-webhook archive database (`archive-{webhookID}.db`) for long-term
+- **`database`** — Archive the full event as a row into the target's
+  own archive database
+  (`archive-{webhook_name}-{target_name}-{target_uuid}.db`) for long-term
   retention, with an optional creation-validated expiry (default: keep
   forever). No external delivery and no retries; an archive write
   failure fails the delivery. See the database target section under
@@ -1888,9 +1906,39 @@ The **database target type** builds on this architecture to provide
 long-term archiving, separate from the per-webhook event database (which
 may prune events under its own retention). Delivering to a database
 target writes the full event — body, headers, method, content type, and
-webhook/entrypoint/event identifiers — as a row into a dedicated archive
-database, `archive-{webhookID}.db`, stored under the data directory
-beside the event database. After each write the archive handle is closed
+webhook/entrypoint/event identifiers — as a row into the target's own
+archive database, `archive-{webhook_name}-{target_name}-{target_uuid}.db`,
+stored under the data directory beside the event database. Each
+`database` target has its own archive file, even when one webhook has
+several.
+
+Both names are made safe for a file name the same way: lowercased, ASCII
+letters and digits kept, every other run of characters turned into a
+single `-`, no `-` at either end, cut to 40 characters, and `unnamed`
+when nothing is left. The target UUID keeps the file name unique. A
+webhook named `Orders (EU)` with a target named `Long-term archive`
+archives into `archive-orders-eu-long-term-archive-{target_uuid}.db`.
+Renaming the webhook or the target renames the file, under the same
+lock the archive writes and the archive sweeper take, so the name on
+disk matches the UI. A rename never replaces a file: if one already has
+the new name, the edit is refused with an error naming that file, and
+the stored name stays. If the archive is not there (the operator moved
+it away), the rename is not an error, and the next write creates the
+file under the new name.
+
+The file is moved just before the new name is saved. If the process
+stops between the two, the archive is left under the new name while the
+UI still shows the old one, and the next delivery starts a second
+archive under the name shown. To bring them back together, stop the
+service before moving anything, and move each archive as its `.db`
+together with any `-wal` and `-shm` beside it, since the `-wal` can hold
+rows that are not yet in the `.db`. If no file has the name shown, move
+the archive under the new name back to it. If a second archive already
+has the name shown, move the archive under the new name out of the data
+directory instead and keep it as you would any archive moved away. Then
+start the service again.
+
+After each write the archive handle is closed
 and reopened, debounced to at most once per second, so an operator can
 move the archive file away for offline archiving without stopping the
 service; a moved or removed archive file is recreated automatically on
@@ -1901,35 +1949,33 @@ older than the expiry are pruned each time the archive is (re)opened. An
 archive write failure is never silent success: the delivery records a
 failed attempt with the error and is marked failed.
 
-Because reopens only happen on writes, an archive belonging to a webhook
-that has stopped receiving events would never be pruned. A background
-**archive sweeper** closes that gap: on the same interval as the event
-retention reaper (`RETENTION_SWEEP_INTERVAL`) it prunes every archive
-whose database target declares a positive expiry, whether or not the
-webhook is still receiving traffic. The sweep never creates an archive —
-a webhook whose archive file does not yet exist is skipped, not
-initialised — it takes the same per-webhook lock the write path uses, so
-it can never interleave with a write, and it leaves the archive closed
-afterwards so the move-the-file-away workflow keeps working. Archives
-with no expiry, or the expiry `never`, are not touched by the sweep at
-all.
+Because reopens only happen on writes, an archive whose target has
+stopped receiving events would never be pruned. A background **archive
+sweeper** closes that gap: on the same interval as the event retention
+reaper (`RETENTION_SWEEP_INTERVAL`) it prunes every archive whose
+database target declares a positive expiry, whether or not the target
+is still receiving traffic. The sweep never creates an archive — a
+target whose archive file does not yet exist is skipped, not initialised
+— it takes the same per-target lock the write path uses, so it can never
+interleave with a write, and it leaves the archive closed afterwards so
+the move-the-file-away workflow keeps working. Archives with no expiry,
+or the expiry `never`, are not touched by the sweep at all.
 
-Note that a webhook has one archive file but may carry more than one
-`database` target, each with its own `expiry`. The shortest expiry
-configured on any of them therefore governs the whole archive, and the
-sweep applies it whether or not the webhook is still receiving events.
-Configure a single `database` target per webhook unless you intend that.
+Because each `database` target has its own archive file, a target's
+`expiry` governs only its own archive. Two `database` targets on one
+webhook with different expiries keep two archives, each pruned on its
+own schedule.
 
-Deleting a webhook releases its archive: the delivery engine's cached
-archive writer is dropped and its file handle closed, so nothing lingers
-after the webhook is gone. The archive **file itself is deliberately
-left on disk**. Unlike the event database — per-webhook working storage
-that is hard-deleted with the webhook — an archive is long-term storage
-an operator may still want to keep or move away for offline retention,
-and destroying it as a side effect of deleting a webhook would be
-unrecoverable. Removing `archive-{webhookID}.db` is the operator's call.
-Deleting a webhook's last `database` target releases the writer the same
-way, and for the same reason leaves the file alone.
+Deleting a webhook releases its archives: the delivery engine's cached
+archive writers are dropped and their file handles closed, so nothing
+lingers after the webhook is gone. The archive **files themselves are
+deliberately left on disk**. Unlike the event database — per-webhook
+working storage that is hard-deleted with the webhook — an archive is
+long-term storage an operator may still want to keep or move away for
+offline retention, and destroying it as a side effect of deleting a
+webhook would be unrecoverable. Removing an `archive-….db` is the
+operator's call. Deleting a `database` target releases its writer the
+same way, and for the same reason leaves its file alone.
 
 The **Slack target type** sends webhook events as formatted messages to
 any Slack-compatible incoming webhook URL (works with Slack, Mattermost,
@@ -2935,13 +2981,15 @@ Components are wired via Uber fx in this order:
 7. `healthcheck.New` — Health check service
 8. `session.New` — Cookie-based session manager (key from database)
 9. `handlers.New` — HTTP handlers
-10. `middleware.New` — HTTP middleware
-11. `delivery.New` — Event-driven delivery engine
-12. `delivery.NewArchiveSweeper` — Periodic pruning of idle archives
-13. `delivery.Engine` → `delivery.Notifier` — interface bridge
-14. `delivery.Engine` → `delivery.WebhookEvictor` — interface bridge so
-    deleting a webhook releases its archive writer
-15. `server.New` — HTTP server and router
+10. `metrics.NewRegistry` — The registry `/metrics` serves
+11. `metrics.New` — The delivery collectors, registered on that registry
+12. `middleware.New` — HTTP middleware
+13. `delivery.New` — Event-driven delivery engine
+14. `delivery.NewArchiveSweeper` — Periodic pruning of idle archives
+15. `delivery.Engine` → `delivery.Notifier` — interface bridge
+16. `delivery.Engine` → `delivery.Archives` — interface bridge so
+    deleting or renaming a webhook or target reaches its archive files
+17. `server.New` — HTTP server and router
 
 The server starts via `fx.Invoke(func(*server.Server, *delivery.Engine,
 *database.RetentionReaper, *delivery.ArchiveSweeper) {})`, which
@@ -2984,6 +3032,12 @@ local record instead of nothing. What that placement gives up is
 recovery of a panic in the six entries above it, none of which does
 more than set a header or start a timer.
 
+Each admin page route group (`/pages`, `/user/*`, `/hooks`,
+`/hook/*`) starts with its own **Recoverer** and, if `SENTRY_DSN` is
+set, its own **Sentry** error reporting. That Recoverer answers a panic
+with the `500` error page in the normal layout; the global one keeps
+the plain-text `500` for every other route.
+
 Additionally, form endpoints (`/pages`, `/user/*`, `/hooks`,
 `/hook/*`) apply a **MaxBodySize** middleware that limits
 POST/PUT/PATCH request bodies to 1 MB. It is registered ahead of the
@@ -3227,8 +3281,9 @@ version is fixed independently of the compiler's:
    rebuilds the binary with `CGO_ENABLED=1` and static linking so it
    runs on musl. Both builds go through `make build`, the relink adding
    its `-extldflags` via `GO_LDFLAGS`, so neither can drop the `-X` that
-   stamps the version. The version arrives as the `VERSION` build arg,
-   since the context has no `.git` (see
+   stamps the version. The version is the `VERSION` build arg if one is
+   given, otherwise derived from the `.git` in the context, and the
+   stage fails if a context with `.git` would stamp `unknown` (see
    [Version stamping](#version-stamping)).
 3. **Runtime stage** (`alpine:3.21`) — copies the static binary and
    `deploy/docker-entrypoint.sh`, creates the `/var/lib/webhooker`
@@ -3260,19 +3315,13 @@ A layer cache lets `docker build .` exit 0 in seconds with the lint and
 test stages replayed rather than executed, which would make a green
 check meaningless. The `check` workflow therefore writes
 `.ci-fingerprint` into the build context before building. Its value is
-the hash of the last commit that touched the build context, so:
+the hash of the commit being checked, so every commit, docs-only ones
+and a squash merge whose tree matches an already-built branch included,
+gets a new fingerprint, invalidates the `COPY . .` layer of both check
+stages, and really runs `make fmt-check`, `golangci-lint`, `make test`,
+and `make build`. A run that reports success ran them.
 
-- Any commit that changes code (including a squash merge whose tree
-  matches an already-built branch) gets a new fingerprint, invalidates
-  the `COPY . .` layer of both check stages, and really runs
-  `make fmt-check`, `golangci-lint`, `make test`, and `make build`. A
-  run that reports success ran them.
-- A docs-only commit leaves the fingerprint unchanged — `.dockerignore`
-  excludes `*.md`, `LICENSE` and `.editorconfig` from the context
-  anyway — so the image replays from cache and costs seconds.
-
-The module download layer sits above `COPY . .` and stays cached either
-way.
+The module download layer sits above `COPY . .` and stays cached.
 
 A separate workflow step, run before the fingerprint is written, covers
 a second way the gate lied: Gitea cancels an in-flight run when a newer

TODO.md

@@ -40,12 +40,6 @@ duplicate. That is deliberate — the alternative is a silent lost
 delivery — and the README says so under Rationale. It is not a defect
 to re-file.
 
-One caveat on reading a green check: a docs-only commit deliberately
-replays from the layer cache
-(https://git.eeqj.de/sneak/webhooker/issues/119), so a green status on
-such a commit evidences a replay rather than an executed run. A code
-commit invalidates the `COPY` layer and genuinely executes.
-
 # Next Step
 
 Clear the rest of the open 1.0.0 milestone

cmd/webhooker/main.go

@@ -16,6 +16,7 @@ import (
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/healthcheck"
 	"sneak.berlin/go/webhooker/internal/logger"
+	"sneak.berlin/go/webhooker/internal/metrics"
 	"sneak.berlin/go/webhooker/internal/middleware"
 	"sneak.berlin/go/webhooker/internal/resetpw"
 	"sneak.berlin/go/webhooker/internal/server"
@@ -177,6 +178,10 @@ func newApp() *fx.App {
 			healthcheck.New,
 			session.New,
 			handlers.New,
+			// The registry /metrics serves, and the delivery
+			// collectors registered on it.
+			metrics.NewRegistry,
+			metrics.New,
 			middleware.New,
 			// The one SSRF guard both target-creation validation
 			// and the delivery dialer consult, so they cannot
@@ -187,11 +192,10 @@ func newApp() *fx.App {
 			// Wire *delivery.Engine as delivery.Notifier so the
 			// webhook handler can notify the engine of new deliveries.
 			func(e *delivery.Engine) delivery.Notifier { return e },
-			// Wire *delivery.Engine as delivery.WebhookEvictor so
-			// deleting a webhook releases its archive writer.
-			func(e *delivery.Engine) delivery.WebhookEvictor {
-				return e
-			},
+			// Wire *delivery.Engine as delivery.Archives so deleting
+			// or renaming a webhook or target reaches its archive
+			// files.
+			func(e *delivery.Engine) delivery.Archives { return e },
 			server.New,
 		),
 		fx.Invoke(

internal/delivery/archive_sweeper.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"go.uber.org/fx"
+	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/lifecycle"
@@ -25,14 +26,14 @@ type ArchiveSweeperParams struct {
 	Logger   *logger.Logger
 }
 
-// ArchiveSweeper periodically prunes expired rows from
-// per-webhook archive databases whose database target carries a
-// positive expiry.
+// ArchiveSweeper periodically prunes expired rows from the
+// archive databases of database targets that carry a positive
+// expiry.
 //
 // Without it, pruning happens only when an archive is
 // (re)opened, and archives are only ever reopened by writes: an
-// archive belonging to a webhook that has stopped receiving
-// events would keep its expired rows forever. The sweep closes
+// archive whose target has stopped receiving events would keep
+// its expired rows forever. The sweep closes
 // that gap without changing anything for archives whose expiry
 // is unset or "never".
 //
@@ -155,7 +156,7 @@ func (s *ArchiveSweeper) run(ctx context.Context) {
 // soft-deleted along with it, so GORM's default scope already
 // excludes them.
 //
-// A failure for one webhook is logged and the sweep continues,
+// A failure for one target is logged and the sweep continues,
 // matching how the write path already treats a prune error as
 // non-fatal.
 func (s *ArchiveSweeper) sweep(ctx context.Context) {
@@ -210,19 +211,20 @@ func (s *ArchiveSweeper) sweepTarget(target *database.Target) {
 		return
 	}
 
-	err = s.eng.dbTarget.sweepWebhook(target.WebhookID, expiry)
+	err = s.eng.dbTarget.sweepArchive(target.ID, expiry)
 	if err == nil {
 		return
 	}
 
-	// A writer evicted underneath the sweep means the operator
-	// deleted the webhook (or its last database target) while the
-	// sweep was walking the target list. That is an ordinary
+	// A writer evicted, or a target row gone, underneath the sweep
+	// means the operator deleted the target or its webhook while
+	// the sweep was walking the target list. That is an ordinary
 	// interleaving, not a failure, so it must not produce an
 	// error line.
-	if errors.Is(err, errArchiveWriterEvicted) {
+	if errors.Is(err, errArchiveWriterEvicted) ||
+		errors.Is(err, gorm.ErrRecordNotFound) {
 		s.log.Debug(
-			"archive sweep: writer evicted mid-sweep",
+			"archive sweep: target deleted mid-sweep",
 			"webhook_id", target.WebhookID,
 			"target_id", target.ID,
 		)

internal/delivery/archive_sweeper_test.go

@@ -34,18 +34,23 @@ const (
 	sweepConcurrentWrites = 20
 )
 
-// sweeperEnv bundles the pieces an archive sweep test drives:
-// a main configuration database holding webhooks and targets, a
-// delivery engine owning the archive writer registry, and the
-// data directory the archive files live in.
-type sweeperEnv struct {
+// archiveTestWebhookName is the name of every webhook
+// seedDatabaseTarget creates. It is not safe in a file name as it
+// stands, so every archive test goes through archiveNamePart.
+const archiveTestWebhookName = "Sweep Test!"
+
+// archiveEnv bundles the pieces an archive test drives: a main
+// configuration database holding webhooks and targets, a delivery
+// engine owning the archive writer registry, the archive sweeper,
+// and the data directory the archive files live in.
+type archiveEnv struct {
 	sweeper *delivery.ArchiveSweeper
 	eng     *delivery.Engine
 	mainDB  *database.Database
 	dataDir string
 }
 
-func setupSweeperTest(t *testing.T) *sweeperEnv {
+func setupArchiveTest(t *testing.T) *archiveEnv {
 	t.Helper()
 
 	dataDir := t.TempDir()
@@ -78,7 +83,7 @@ func setupSweeperTest(t *testing.T) *sweeperEnv {
 		1,
 	)
 
-	return &sweeperEnv{
+	return &archiveEnv{
 		sweeper: delivery.NewTestArchiveSweeper(
 			mainDB, eng, log,
 		),
@@ -88,25 +93,27 @@ func setupSweeperTest(t *testing.T) *sweeperEnv {
 	}
 }
 
-// archivePath returns where the engine keeps a webhook's
-// archive file.
-func (env *sweeperEnv) archivePath(webhookID string) string {
+// archivePath returns where the engine keeps a database target's
+// archive file, for the names seedDatabaseTarget gave it.
+func (env *archiveEnv) archivePath(tgt *database.Target) string {
 	return filepath.Join(
-		env.dataDir, fmt.Sprintf("archive-%s.db", webhookID),
+		env.dataDir,
+		delivery.ArchiveFileName(
+			archiveTestWebhookName, tgt.Name, tgt.ID,
+		),
 	)
 }
 
 // seedDatabaseTarget creates a webhook with one database target
-// carrying the given target config JSON, and returns the
-// webhook id.
-func (env *sweeperEnv) seedDatabaseTarget(
+// carrying the given target config JSON, and returns the target.
+func (env *archiveEnv) seedDatabaseTarget(
 	t *testing.T, configJSON string,
-) string {
+) *database.Target {
 	t.Helper()
 
 	wh := &database.Webhook{
 		UserID: uuid.New().String(),
-		Name:   "sweep-test",
+		Name:   archiveTestWebhookName,
 	}
 	require.NoError(
 		t,
@@ -115,9 +122,19 @@ func (env *sweeperEnv) seedDatabaseTarget(
 			Create(wh).Error,
 	)
 
+	return env.addDatabaseTarget(t, wh.ID, configJSON)
+}
+
+// addDatabaseTarget creates one more database target on an
+// existing webhook and returns it.
+func (env *archiveEnv) addDatabaseTarget(
+	t *testing.T, webhookID, configJSON string,
+) *database.Target {
+	t.Helper()
+
 	tgt := &database.Target{
-		WebhookID: wh.ID,
-		Name:      "archive",
+		WebhookID: webhookID,
+		Name:      "Archive",
 		Type:      database.TargetTypeDatabase,
 		Active:    true,
 		Config:    configJSON,
@@ -129,19 +146,19 @@ func (env *sweeperEnv) seedDatabaseTarget(
 			Create(tgt).Error,
 	)
 
-	return wh.ID
+	return tgt
 }
 
-// seedArchiveRows creates the archive file for a webhook and
+// seedArchiveRows creates the archive file for a target and
 // inserts one row per supplied archived-at timestamp, returning
 // the archive path. The handle is closed before returning, so
 // the archive is idle exactly as it would be with no traffic.
-func (env *sweeperEnv) seedArchiveRows(
-	t *testing.T, webhookID string, archivedAt ...time.Time,
+func (env *archiveEnv) seedArchiveRows(
+	t *testing.T, tgt *database.Target, archivedAt ...time.Time,
 ) string {
 	t.Helper()
 
-	path := env.archivePath(webhookID)
+	path := env.archivePath(tgt)
 
 	sqlDB, err := sql.Open(
 		"sqlite", fmt.Sprintf("file:%s?mode=rwc", path),
@@ -160,7 +177,7 @@ func (env *sweeperEnv) seedArchiveRows(
 	for i, at := range archivedAt {
 		row := delivery.ExportArchivedEvent{
 			EventID:    fmt.Sprintf("ev-%d", i),
-			WebhookID:  webhookID,
+			WebhookID:  tgt.WebhookID,
 			Method:     http.MethodPost,
 			Body:       `{"seeded":true}`,
 			ArchivedAt: at,
@@ -243,13 +260,13 @@ func TestArchiveSweeper_LoopOutlivesStartHookContext(
 ) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 
 	now := time.Now()
 	path := env.seedArchiveRows(
-		t, webhookID,
+		t, tgt,
 		now.Add(-48*time.Hour),
 		now.Add(-time.Minute),
 	)
@@ -287,60 +304,60 @@ func TestArchiveSweeper_LoopOutlivesStartHookContext(
 }
 
 // TestArchiveSweep_DoesNotResurrectEvictedWriter covers the
-// interleaving where a sweep tick has already listed a webhook's
-// target when the webhook is deleted and its writer evicted. The
-// sweep must not put a writer back into the registry: nothing
-// would ever evict it again, which is precisely the leak this
-// change exists to close.
+// interleaving where a sweep tick has already listed a target
+// when the target is deleted and its writer evicted. The sweep
+// must not put a writer back into the registry: nothing would
+// ever evict it again, which is precisely the leak this change
+// exists to close.
 func TestArchiveSweep_DoesNotResurrectEvictedWriter(
 	t *testing.T,
 ) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	env.seedArchiveRows(
-		t, webhookID, time.Now().Add(-48*time.Hour),
+		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
 	// Prime the registry the way a delivery would, then evict as
 	// the deletion path does. The target row is deliberately left
-	// in place: this is the tick that listed the webhook before
+	// in place: this is the tick that listed the target before
 	// the deletion committed.
-	_, err := env.eng.ExportEnsureArchiveWriter(webhookID)
+	_, err := env.eng.ExportEnsureArchiveWriter(tgt.ID)
 	require.NoError(t, err)
 
-	env.eng.EvictWebhook(webhookID)
-	require.False(t, env.eng.ExportHasArchiveWriter(webhookID))
+	env.eng.EvictTarget(tgt.ID)
+	require.False(t, env.eng.ExportHasArchiveWriter(tgt.ID))
 
 	env.sweeper.ExportSweep(context.Background())
 
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter(webhookID),
-		"a sweep must never re-register a writer for a webhook "+
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		"a sweep must never re-register a writer for a target "+
 			"whose registry entry has already been released",
 	)
 }
 
 // TestArchiveSweep_LeavesNoRegistryEntry states the same
 // invariant in its general form: sweeping an archive whose
-// webhook has no cached writer must not leave one behind, so the
+// target has no cached writer must not leave one behind, so the
 // registry keeps holding only writers a delivery created and an
 // eviction can reach.
 func TestArchiveSweep_LeavesNoRegistryEntry(t *testing.T) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	path := env.seedArchiveRows(
-		t, webhookID,
+		t, tgt,
 		time.Now().Add(-48*time.Hour),
 		time.Now().Add(-time.Minute),
 	)
 
-	require.False(t, env.eng.ExportHasArchiveWriter(webhookID))
+	require.False(t, env.eng.ExportHasArchiveWriter(tgt.ID))
 
 	env.sweeper.ExportSweep(context.Background())
 
@@ -349,7 +366,7 @@ func TestArchiveSweep_LeavesNoRegistryEntry(t *testing.T) {
 		"the sweep must still prune an idle archive",
 	)
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter(webhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"the sweep must release the registry entry it created",
 	)
 }
@@ -364,34 +381,31 @@ func TestArchiveSweep_KeepsWriterAdoptedByDelivery(
 ) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	env.seedArchiveRows(
-		t, webhookID, time.Now().Add(-48*time.Hour),
+		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
 	webhookDB := testWebhookDB(t)
 	event := seedEvent(t, webhookDB, `{"n":1}`)
-	event.WebhookID = webhookID
-	d := seedDatabaseTargetDelivery(
-		t, webhookDB, event, `{"expiry":"1h"}`,
-	)
+	d := seedDatabaseTargetDelivery(t, webhookDB, event, tgt)
 
 	env.sweeper.ExportSweep(context.Background())
-	require.False(t, env.eng.ExportHasArchiveWriter(webhookID))
+	require.False(t, env.eng.ExportHasArchiveWriter(tgt.ID))
 
 	env.eng.ExportDeliverDatabase(webhookDB, d)
 
 	assert.True(
-		t, env.eng.ExportHasArchiveWriter(webhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"a delivery's writer must stay registered",
 	)
 
 	env.sweeper.ExportSweep(context.Background())
 
 	assert.True(
-		t, env.eng.ExportHasArchiveWriter(webhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"a sweep must not drop a writer a delivery owns",
 	)
 }
@@ -423,15 +437,15 @@ func TestArchiveSweep_KeepsWriterAdoptedDuringSweep(
 ) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	env.seedArchiveRows(
-		t, webhookID, time.Now().Add(-48*time.Hour),
+		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
 	sweepWriter, created, err := env.eng.ExportSweepWriterFor(
-		webhookID,
+		tgt.ID,
 	)
 	require.NoError(t, err)
 	require.True(
@@ -442,37 +456,34 @@ func TestArchiveSweep_KeepsWriterAdoptedDuringSweep(
 	// The delivery lands mid-sweep and adopts the entry.
 	webhookDB := testWebhookDB(t)
 	event := seedEvent(t, webhookDB, `{"n":1}`)
-	event.WebhookID = webhookID
-	d := seedDatabaseTargetDelivery(
-		t, webhookDB, event, `{"expiry":"1h"}`,
-	)
+	d := seedDatabaseTargetDelivery(t, webhookDB, event, tgt)
 
 	env.eng.ExportDeliverDatabase(webhookDB, d)
 
-	adopted := env.eng.ExportArchiveWriterFor(webhookID)
+	adopted := env.eng.ExportArchiveWriterFor(tgt.ID)
 	require.NotNil(t, adopted)
 	require.True(
 		t, sweepWriter.Same(adopted),
 		"the delivery must have adopted the sweep's writer",
 	)
 	require.True(
-		t, env.eng.ExportArchiveHandleOpen(webhookID),
+		t, env.eng.ExportArchiveHandleOpen(tgt.ID),
 		"the delivery leaves the archive handle open",
 	)
 
 	// The sweep finishes.
-	env.eng.ExportReleaseSweepWriter(webhookID, sweepWriter)
+	env.eng.ExportReleaseSweepWriter(tgt.ID, sweepWriter)
 
 	require.True(
-		t, env.eng.ExportHasArchiveWriter(webhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"a writer adopted by a delivery during a sweep must "+
 			"stay registered, or its open handle is unreachable",
 	)
 
-	env.eng.EvictWebhook(webhookID)
+	env.eng.EvictTarget(tgt.ID)
 
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter(webhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"the adopted writer must still be evictable",
 	)
 	assert.False(
@@ -481,34 +492,34 @@ func TestArchiveSweep_KeepsWriterAdoptedDuringSweep(
 	)
 }
 
-// TestArchiveSweep_ContinuesAfterPerWebhookFailure proves a
-// failure for one webhook does not abort the sweep for the
+// TestArchiveSweep_ContinuesAfterPerTargetFailure proves a
+// failure for one target does not abort the sweep for the
 // others: an unparseable expiry and an unreadable archive both
 // have to be logged and stepped over.
-func TestArchiveSweep_ContinuesAfterPerWebhookFailure(
+func TestArchiveSweep_ContinuesAfterPerTargetFailure(
 	t *testing.T,
 ) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
 	// Seeded first so the sweep reaches them before the healthy
-	// webhook: targets come back in insertion order.
-	badConfigID := env.seedDatabaseTarget(t, `{"expiry":"!!!"}`)
+	// target: targets come back in insertion order.
+	badConfig := env.seedDatabaseTarget(t, `{"expiry":"!!!"}`)
 	env.seedArchiveRows(
-		t, badConfigID, time.Now().Add(-48*time.Hour),
+		t, badConfig, time.Now().Add(-48*time.Hour),
 	)
 
-	corruptID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	corrupt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	require.NoError(t, os.WriteFile(
-		env.archivePath(corruptID),
+		env.archivePath(corrupt),
 		[]byte("this is not a sqlite database"),
 		0o600,
 	))
 
-	healthyID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	healthy := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	healthyPath := env.seedArchiveRows(
-		t, healthyID,
+		t, healthy,
 		time.Now().Add(-48*time.Hour),
 		time.Now().Add(-time.Minute),
 	)
@@ -518,14 +529,14 @@ func TestArchiveSweep_ContinuesAfterPerWebhookFailure(
 	assert.Equal(
 		t, []string{sweepRowNew},
 		archivedEventIDs(t, healthyPath),
-		"a failure for an earlier webhook must not stop the "+
+		"a failure for an earlier target must not stop the "+
 			"sweep from pruning the ones after it",
 	)
 }
 
 // TestArchiveSweep_OpenExistingDoesNotCreateFile pins the second
 // of the two no-create guards. The first is the stat in
-// sweepWebhook; this one is the SQLite open mode, which is what
+// sweepExpired; this one is the SQLite open mode, which is what
 // protects the window between that stat and the open. Flipping
 // the sweep's mode to create-if-missing makes this fail.
 func TestArchiveSweep_OpenExistingDoesNotCreateFile(
@@ -561,13 +572,13 @@ func TestArchiveSweep_OpenExistingDoesNotCreateFile(
 func TestArchiveSweep_PrunesIdleArchive(t *testing.T) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 
 	now := time.Now()
 	path := env.seedArchiveRows(
-		t, webhookID,
+		t, tgt,
 		now.Add(-48*time.Hour),
 		now.Add(-time.Minute),
 	)
@@ -600,11 +611,11 @@ func TestArchiveSweep_PrunesIdleArchive(t *testing.T) {
 func TestArchiveSweep_LeavesArchiveClosed(t *testing.T) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	path := env.seedArchiveRows(
-		t, webhookID, time.Now().Add(-48*time.Hour),
+		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
 	w := delivery.NewExportArchiveWriter(
@@ -640,35 +651,32 @@ func TestArchiveSweep_ClosesHandleOfRegisteredWriter(
 ) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	env.seedArchiveRows(
-		t, webhookID, time.Now().Add(-48*time.Hour),
+		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
 	webhookDB := testWebhookDB(t)
 	event := seedEvent(t, webhookDB, `{"n":1}`)
-	event.WebhookID = webhookID
-	d := seedDatabaseTargetDelivery(
-		t, webhookDB, event, `{"expiry":"1h"}`,
-	)
+	d := seedDatabaseTargetDelivery(t, webhookDB, event, tgt)
 
 	env.eng.ExportDeliverDatabase(webhookDB, d)
 
 	require.True(
-		t, env.eng.ExportArchiveHandleOpen(webhookID),
+		t, env.eng.ExportArchiveHandleOpen(tgt.ID),
 		"the delivery must leave the archive handle open",
 	)
 
 	env.sweeper.ExportSweep(context.Background())
 
 	require.True(
-		t, env.eng.ExportHasArchiveWriter(webhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"the delivery's registry entry must survive the sweep",
 	)
 	assert.False(
-		t, env.eng.ExportArchiveHandleOpen(webhookID),
+		t, env.eng.ExportArchiveHandleOpen(tgt.ID),
 		"the sweep must leave the archive closed",
 	)
 }
@@ -684,11 +692,11 @@ func TestArchiveSweep_NeverExpiryUntouched(t *testing.T) {
 		`{"expiry":""}`,
 		"",
 	} {
-		env := setupSweeperTest(t)
+		env := setupArchiveTest(t)
 
-		webhookID := env.seedDatabaseTarget(t, configJSON)
+		tgt := env.seedDatabaseTarget(t, configJSON)
 		path := env.seedArchiveRows(
-			t, webhookID,
+			t, tgt,
 			time.Now().Add(-10000*time.Hour),
 		)
 
@@ -699,7 +707,7 @@ func TestArchiveSweep_NeverExpiryUntouched(t *testing.T) {
 			"config %q must keep rows forever", configJSON,
 		)
 		assert.False(
-			t, env.eng.ExportHasArchiveWriter(webhookID),
+			t, env.eng.ExportHasArchiveWriter(tgt.ID),
 			"config %q must leave no registry entry behind",
 			configJSON,
 		)
@@ -722,10 +730,10 @@ func TestArchiveSweep_NeverExpirySkipsBeforeOpening(
 ) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"never"}`)
-	path := env.archivePath(webhookID)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"never"}`)
+	path := env.archivePath(tgt)
 
 	seedUnmigratedArchive(t, path)
 	require.False(t, archiveTableExists(t, path))
@@ -768,16 +776,16 @@ func archiveTableExists(t *testing.T, path string) bool {
 }
 
 // TestArchiveSweep_DoesNotCreateArchiveFile proves the sweep
-// never conjures an archive: a webhook with a database target
-// that has never received an event must still have no archive
-// file (nor SQLite sidecar) after a sweep.
+// never conjures an archive: a database target that has never
+// received an event must still have no archive file (nor SQLite
+// sidecar) after a sweep, and no registry entry either.
 func TestArchiveSweep_DoesNotCreateArchiveFile(t *testing.T) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
-	path := env.archivePath(webhookID)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	path := env.archivePath(tgt)
 
 	require.NoFileExists(t, path)
 
@@ -789,6 +797,11 @@ func TestArchiveSweep_DoesNotCreateArchiveFile(t *testing.T) {
 			"the sweep must not create an archive file",
 		)
 	}
+
+	assert.False(
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		"the sweep must leave no registry entry behind",
+	)
 }
 
 // TestArchiveSweep_DoesNotCreateAfterWriterExists covers the
@@ -800,11 +813,11 @@ func TestArchiveSweep_DoesNotCreateAfterWriterExists(
 ) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 
-	path, err := env.eng.ExportEnsureArchiveWriter(webhookID)
+	path, err := env.eng.ExportEnsureArchiveWriter(tgt.ID)
 	require.NoError(t, err)
 	require.NoFileExists(t, path)
 
@@ -819,17 +832,17 @@ func TestArchiveSweep_DoesNotCreateAfterWriterExists(
 func TestArchiveSweep_SkipsDeletedWebhookTargets(t *testing.T) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	path := env.seedArchiveRows(
-		t, webhookID, time.Now().Add(-48*time.Hour),
+		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
 	require.NoError(
 		t,
 		env.mainDB.DB().
-			Where("webhook_id = ?", webhookID).
+			Where("webhook_id = ?", tgt.WebhookID).
 			Delete(&database.Target{}).Error,
 	)
 
@@ -842,14 +855,14 @@ func TestArchiveSweep_SkipsDeletedWebhookTargets(t *testing.T) {
 }
 
 // TestArchiveSweep_ConcurrentWrites proves the sweep serialises
-// against writes through the per-webhook writer mutex. Run
-// under -race, an unsynchronised sweep would be caught here.
+// against writes through the target's writer mutex. Run under
+// -race, an unsynchronised sweep would be caught here.
 func TestArchiveSweep_ConcurrentWrites(t *testing.T) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 
 	webhookDB := testWebhookDB(t)
 
@@ -862,13 +875,10 @@ func TestArchiveSweep_ConcurrentWrites(t *testing.T) {
 
 	for range sweepConcurrentWrites {
 		event := seedEvent(t, webhookDB, `{"n":1}`)
-		event.WebhookID = webhookID
 
 		deliveries = append(
 			deliveries,
-			seedDatabaseTargetDelivery(
-				t, webhookDB, event, `{"expiry":"1h"}`,
-			),
+			seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
 		)
 	}
 
@@ -894,7 +904,7 @@ func TestArchiveSweep_ConcurrentWrites(t *testing.T) {
 
 	wg.Wait()
 
-	assert.FileExists(t, env.archivePath(webhookID))
+	assert.FileExists(t, env.archivePath(tgt))
 }
 
 // TestArchiveSweeper_StopsCleanly proves the background loop
@@ -902,11 +912,11 @@ func TestArchiveSweep_ConcurrentWrites(t *testing.T) {
 func TestArchiveSweeper_StopsCleanly(t *testing.T) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
-	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 	env.seedArchiveRows(
-		t, webhookID, time.Now().Add(-48*time.Hour),
+		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
 	env.sweeper.ExportSetInterval(time.Millisecond)
@@ -930,7 +940,7 @@ func TestArchiveSweeper_StopHookHonoursStopTimeout(
 ) {
 	t.Parallel()
 
-	env := setupSweeperTest(t)
+	env := setupArchiveTest(t)
 
 	lc := &recordingLifecycle{}
 	env.sweeper.ExportRegisterHooks(lc)

internal/delivery/engine.go

@@ -14,6 +14,7 @@ import (
 	"go.uber.org/fx"
 	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/globals"
 	"sneak.berlin/go/webhooker/internal/lifecycle"
 	"sneak.berlin/go/webhooker/internal/logger"
 	"sneak.berlin/go/webhooker/internal/metrics"
@@ -122,21 +123,24 @@ type Notifier interface {
 	Notify(tasks []Task)
 }
 
-// WebhookEvictor releases the delivery engine's per-webhook
-// state for a webhook that no longer needs it — currently the
-// cached archive writer of the database target, whose open
-// file handle would otherwise outlive the webhook.
+// Archives is how the handlers keep the database targets' archive
+// files in step with the configuration. Deleting a webhook or a
+// target releases the cached archive writers, whose open file
+// handles would otherwise outlive them; renaming one renames the
+// archive files, which are named for the webhook and the target
+// (see ArchiveFileName).
 //
-// It is deliberately separate from Notifier and deliberately
-// one method wide: archiving lifecycle is not notification, and
-// a single-method interface keeps the handlers package free of
-// any dependency on the engine's internals while staying
-// trivially fakeable in tests.
+// It is deliberately separate from Notifier: archiving lifecycle
+// is not notification, and a small interface keeps the handlers
+// package free of any dependency on the engine's internals while
+// staying trivially fakeable in tests.
 //
-// EvictWebhook never deletes an archive file. It is idempotent
-// and is a no-op for a webhook with no engine state.
-type WebhookEvictor interface {
+// Neither eviction deletes an archive file. Both are idempotent
+// and are no-ops for a webhook or target with no engine state.
+type Archives interface {
 	EvictWebhook(webhookID string)
+	EvictTarget(targetID string)
+	Rename(targetID, webhookName, targetName string) error
 }
 
 // EngineParams are the fx dependencies for the delivery
@@ -146,8 +150,10 @@ type EngineParams struct {
 
 	DB        *database.Database
 	DBManager *database.WebhookDBManager
+	Globals   *globals.Globals
 	Logger    *logger.Logger
 	SSRFGuard *Guard
+	Metrics   *metrics.Set
 }
 
 // Engine processes queued deliveries in the background
@@ -167,10 +173,14 @@ type Engine struct {
 	retryCh    chan Task
 	workers    int
 
-	// mtr is the delivery metric set. Production wires the
-	// process-wide one; a test can substitute a set registered on
-	// a private registry so its assertions are not disturbed by
-	// deliveries other tests are making at the same time.
+	// version is the running build's version, the one the web UI
+	// footer shows. userAgent puts it on every outbound request.
+	version string
+
+	// mtr is the delivery metric set. Production wires the one
+	// registered on the registry /metrics serves; a test can
+	// substitute a set registered on a registry it holds, so it can
+	// gather what its own deliveries recorded.
 	mtr *metrics.Set
 
 	// targets maps each target type to its implementation.
@@ -181,7 +191,7 @@ type Engine struct {
 	httpTarget *httpTarget
 
 	// dbTarget is retained so the engine can reach the archive
-	// writer registry for webhook eviction and the idle sweep.
+	// writer registry for eviction, renames and the idle sweep.
 	dbTarget *databaseTarget
 
 	// inflight is the set of deliveries this engine currently owns.
@@ -204,7 +214,8 @@ func New(
 		deliveryCh: make(chan Task, deliveryChannelSize),
 		retryCh:    make(chan Task, retryChannelSize),
 		workers:    defaultWorkers,
-		mtr:        metrics.Default(),
+		version:    params.Globals.Version,
+		mtr:        params.Metrics,
 	}
 
 	e.initTargets(&http.Client{
@@ -249,17 +260,44 @@ func (e *Engine) Notify(tasks []Task) {
 	}
 }
 
-// EvictWebhook implements WebhookEvictor. It releases the
-// engine's per-webhook archiving state: the database target's
-// cached archive writer is dropped from the registry and its
-// file handle closed. The archive file itself is left on disk
-// — it is long-term storage the operator owns.
+// EvictWebhook implements Archives. The cached archive writer of
+// every database target of the webhook is dropped from the
+// registry and its file handle closed. The archive files
+// themselves are left on disk — they are long-term storage the
+// operator owns.
 func (e *Engine) EvictWebhook(webhookID string) {
 	if e.dbTarget == nil {
 		return
 	}
 
-	e.dbTarget.evict(webhookID)
+	e.dbTarget.evictWebhook(webhookID)
+}
+
+// EvictTarget implements Archives. It is EvictWebhook for a single
+// database target, and leaves the archive file on disk the same
+// way.
+func (e *Engine) EvictTarget(targetID string) {
+	if e.dbTarget == nil {
+		return
+	}
+
+	e.dbTarget.evict(targetID)
+}
+
+// Rename implements Archives. It renames a database target's
+// archive file to ArchiveFileName(webhookName, targetName,
+// targetID), under the lock the target's archive writes and the
+// idle sweep take. It never replaces a file: if one already has the
+// new name, the error is ErrArchiveNameTaken. The caller renames
+// before it saves the new name: see databaseTarget.rename.
+func (e *Engine) Rename(
+	targetID, webhookName, targetName string,
+) error {
+	if e.dbTarget == nil {
+		return nil
+	}
+
+	return e.dbTarget.rename(targetID, webhookName, targetName)
 }
 
 // ScheduleRetry schedules a task to be re-enqueued onto the
@@ -300,6 +338,13 @@ func (e *Engine) ScheduleRetry(
 	})
 }
 
+// userAgent is the User-Agent header of every http and slack
+// delivery request: the program name and the running build's
+// version.
+func (e *Engine) userAgent() string {
+	return "webhooker/" + e.version
+}
+
 // registerHooks wires the engine's start and stop into the fx
 // lifecycle. The start hook's context is deliberately ignored
 // (see start for why the worker pool must not inherit it); the
@@ -366,7 +411,8 @@ func (e *Engine) start() {
 // Once the pool has drained it closes the archive writers, so a
 // clean stop leaves no archive -wal behind. Nothing else holds a
 // writer for long by then: the archive sweeper stops before the
-// engine, and deleting a webhook only closes one. If the pool did
+// engine, and deleting or renaming a webhook or target only closes
+// or moves one. If the pool did
 // not drain in time, the writers are left open, as a kill would
 // leave them. Closing them would wait for any write in progress,
 // and a worker still running would then open new writers that

internal/delivery/engine_lifecycle_test.go

@@ -2,7 +2,6 @@ package delivery_test
 
 import (
 	"context"
-	"fmt"
 	"path/filepath"
 	"testing"
 	"time"
@@ -10,6 +9,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/fx"
+	"gorm.io/gorm/clause"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
@@ -272,22 +272,35 @@ func TestEngine_StopHookHonoursStopTimeout(t *testing.T) {
 	requireStopHookExpires(t, lc.hooks[0], "delivery engine")
 }
 
-// deliverToArchive runs one delivery to a database target through
-// the running engine and returns the webhook's archive file path.
-// The archive writer holds the file open afterwards.
-func deliverToArchive(t *testing.T, s iSetup) string {
+// deliverToArchive gives the setup's webhook a database target,
+// runs one delivery to it through the running engine, and returns
+// the target's ID and archive file path. The archive writer holds
+// the file open afterwards.
+func deliverToArchive(t *testing.T, s iSetup) (string, string) {
 	t.Helper()
 
+	iCreateWebhook(t, s.MainDB, s.WebhookID, "hook")
+
+	tgt := &database.Target{
+		WebhookID: s.WebhookID,
+		Name:      "archive",
+		Type:      database.TargetTypeDatabase,
+	}
+	require.NoError(
+		t, s.MainDB.Omit(clause.Associations).Create(tgt).Error,
+	)
+
 	deliveryID, task := seedLogTask(t, s)
+	task.TargetID = tgt.ID
 	task.TargetType = database.TargetTypeDatabase
 
 	s.Engine.Notify([]delivery.Task{task})
 
 	iWaitForDelivered(t, s.WebhookDB, deliveryID)
 
-	return filepath.Join(
+	return tgt.ID, filepath.Join(
 		filepath.Dir(s.DBMgr.DBPath(s.WebhookID)),
-		fmt.Sprintf("archive-%s.db", s.WebhookID),
+		"archive-hook-archive-"+tgt.ID+".db",
 	)
 }
 
@@ -304,7 +317,7 @@ func TestEngine_StopHookClosesArchives(t *testing.T) {
 
 	lc := startEngineViaHook(t, s.Engine)
 
-	path := deliverToArchive(t, s)
+	_, path := deliverToArchive(t, s)
 	require.FileExists(
 		t, path+"-wal",
 		"an open archive should have a -wal for the stop to remove",
@@ -338,7 +351,7 @@ func TestEngine_StopHookTimeoutLeavesArchivesOpen(t *testing.T) {
 
 	lc := startEngineViaHook(t, s.Engine)
 
-	deliverToArchive(t, s)
+	targetID, _ := deliverToArchive(t, s)
 
 	release := make(chan struct{})
 
@@ -352,7 +365,7 @@ func TestEngine_StopHookTimeoutLeavesArchivesOpen(t *testing.T) {
 	requireStopHookExpires(t, lc.hooks[0], "delivery engine")
 
 	require.True(
-		t, s.Engine.ExportArchiveHandleOpen(s.WebhookID),
+		t, s.Engine.ExportArchiveHandleOpen(targetID),
 		"a stop that timed out must not close archive writers",
 	)
 }

internal/delivery/engine_test.go

@@ -351,23 +351,15 @@ func TestDeliverDatabase_ImmediateSuccess(
 
 	db := testWebhookDB(t)
 
-	// The database target archives for real now, so the engine
-	// needs a webhook DB manager to locate the data directory.
-	e := delivery.NewTestEngineWithDB(
-		nil,
-		database.NewTestWebhookDBManager(t.TempDir()),
-		slog.New(slog.NewTextHandler(
-			os.Stderr,
-			&slog.HandlerOptions{Level: slog.LevelDebug},
-		)),
-		&http.Client{Timeout: 5 * time.Second},
-		1,
-	)
+	// The database target archives for real, so the engine needs
+	// the target in the main database and a data directory.
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
 
 	event := seedEvent(t, db, `{"db":"target"}`)
-	d := seedDatabaseTargetDelivery(t, db, event, "")
+	d := seedDatabaseTargetDelivery(t, db, event, tgt)
 
-	e.ExportDeliverDatabase(db, d)
+	env.eng.ExportDeliverDatabase(db, d)
 
 	var updated database.Delivery
 
@@ -1247,11 +1239,6 @@ func TestDoHTTPRequest_ForwardsHeaders(t *testing.T) {
 		testContentType,
 		receivedHeaders.Get("Content-Type"),
 	)
-
-	assert.Equal(t,
-		"webhooker/1.0",
-		receivedHeaders.Get("User-Agent"),
-	)
 }
 
 // The event's stored inbound headers carry the same Content-Type the
@@ -1320,6 +1307,7 @@ func TestApplyRequestHeaders_SendsOneContentType(t *testing.T) {
 					ContentType: tc.event,
 				},
 				cfg,
+				"webhooker/dev",
 			)
 
 			assert.Equal(t,
@@ -1336,32 +1324,27 @@ func TestProcessDelivery_RoutesToCorrectHandler(
 
 	db := testWebhookDB(t)
 
-	// The database target archives for real now, so the engine
-	// needs a webhook DB manager to locate the data directory.
-	e := delivery.NewTestEngineWithDB(
-		nil,
-		database.NewTestWebhookDBManager(t.TempDir()),
-		slog.New(slog.NewTextHandler(
-			os.Stderr,
-			&slog.HandlerOptions{Level: slog.LevelDebug},
-		)),
-		&http.Client{Timeout: 5 * time.Second},
-		1,
-	)
+	// The database target archives for real, so the engine needs
+	// the target in the main database and a data directory.
+	env := setupArchiveTest(t)
+	archive := env.seedDatabaseTarget(t, "")
 
 	tests := []struct {
 		name       string
 		targetType database.TargetType
+		targetID   string
 		wantStatus database.DeliveryStatus
 	}{
 		{
 			"database target",
 			database.TargetTypeDatabase,
+			archive.ID,
 			database.DeliveryStatusDelivered,
 		},
 		{
 			"log target",
 			database.TargetTypeLog,
+			uuid.New().String(),
 			database.DeliveryStatusDelivered,
 		},
 	}
@@ -1371,7 +1354,7 @@ func TestProcessDelivery_RoutesToCorrectHandler(
 			t.Parallel()
 
 			runRoutingSubtest(
-				t, db, e, tt.targetType,
+				t, db, env.eng, tt.targetType, tt.targetID,
 				tt.wantStatus,
 			)
 		})
@@ -1383,6 +1366,7 @@ func runRoutingSubtest(
 	db *gorm.DB,
 	e *delivery.Engine,
 	targetType database.TargetType,
+	targetID string,
 	wantStatus database.DeliveryStatus,
 ) {
 	t.Helper()
@@ -1390,8 +1374,7 @@ func runRoutingSubtest(
 	event := seedEvent(t, db, `{"routing":"test"}`)
 
 	dlv := seedDelivery(
-		t, db, event.ID,
-		uuid.New().String(),
+		t, db, event.ID, targetID,
 		database.DeliveryStatusPending,
 	)
 

internal/delivery/export_test.go

@@ -9,6 +9,7 @@ import (
 	"net/url"
 	"time"
 
+	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/fx"
 	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/database"
@@ -40,11 +41,6 @@ const (
 	ExportPendingSweepMinAge = pendingSweepMinAge
 )
 
-// ExportIsBlockedIP exposes isBlockedIP for testing.
-func ExportIsBlockedIP(ip net.IP) bool {
-	return isBlockedIP(ip)
-}
-
 // NewTestGuard builds an SSRF Guard from an explicit egress
 // allowlist, without going through config. Passing no prefixes
 // yields the default guard, which blocks every private/reserved
@@ -70,6 +66,11 @@ func ExportBlockedNetworks() []*net.IPNet {
 	return blockedNetworks
 }
 
+// ExportBlockedPublicNetworks exposes blockedPublicNetworks.
+func ExportBlockedPublicNetworks() []*net.IPNet {
+	return blockedPublicNetworks
+}
+
 // ExportIsForwardableHeader exposes isForwardableHeader.
 func ExportIsForwardableHeader(name string) bool {
 	return isForwardableHeader(name)
@@ -82,8 +83,9 @@ func ExportApplyRequestHeaders(
 	req *http.Request,
 	event *database.Event,
 	cfg *HTTPTargetConfig,
+	userAgent string,
 ) []string {
-	return applyRequestHeaders(req, event, cfg)
+	return applyRequestHeaders(req, event, cfg, userAgent)
 }
 
 // ExportTruncate exposes truncate for testing.
@@ -399,7 +401,7 @@ func NewTestEngine(
 		deliveryCh: make(chan Task, deliveryChannelSize),
 		retryCh:    make(chan Task, retryChannelSize),
 		workers:    workers,
-		mtr:        metrics.Default(),
+		mtr:        metrics.New(prometheus.NewRegistry()),
 	}
 	e.initTargets(client)
 
@@ -414,7 +416,7 @@ func NewTestEngineSmallRetry(
 	e := &Engine{
 		log:     log,
 		retryCh: make(chan Task, 1),
-		mtr:     metrics.Default(),
+		mtr:     metrics.New(prometheus.NewRegistry()),
 	}
 	e.initTargets(nil)
 
@@ -437,7 +439,7 @@ func NewTestEngineWithDB(
 		deliveryCh: make(chan Task, deliveryChannelSize),
 		retryCh:    make(chan Task, retryChannelSize),
 		workers:    workers,
-		mtr:        metrics.Default(),
+		mtr:        metrics.New(prometheus.NewRegistry()),
 	}
 	e.initTargets(client)
 
@@ -445,8 +447,7 @@ func NewTestEngineWithDB(
 }
 
 // ExportSetMetrics substitutes the engine's metric set, so a test can
-// assert on collectors registered on a private registry instead of
-// the process-wide ones every other test is also moving.
+// assert on collectors registered on a registry it holds.
 func (e *Engine) ExportSetMetrics(mtr *metrics.Set) {
 	e.mtr = mtr
 }
@@ -473,7 +474,7 @@ func NewTestCircuitBreaker(
 type ExportArchivedEvent = archivedEvent
 
 // ExportArchiveWriter wraps an archiveWriter so black-box tests
-// can exercise the per-webhook archive file mechanics.
+// can exercise the archive file mechanics.
 type ExportArchiveWriter struct {
 	w *archiveWriter
 }
@@ -548,6 +549,12 @@ func (e *ExportArchiveWriter) Evict() {
 	e.w.evict()
 }
 
+// Rename gives the archive file a new name in the same directory,
+// as a rename of the webhook or target does.
+func (e *ExportArchiveWriter) Rename(name string) error {
+	return e.w.rename(name)
+}
+
 // HandleOpen reports whether the writer currently holds an open
 // archive handle.
 func (e *ExportArchiveWriter) HandleOpen() bool {
@@ -567,16 +574,16 @@ func (e *ExportArchiveWriter) Same(
 }
 
 // ExportArchiveWriterFor returns the archive writer the registry
-// currently caches for a webhook, or nil when none is cached. It
-// never creates one, so a test can hold a reference to the very
-// writer an eviction is about to detach.
+// currently caches for a database target, or nil when none is
+// cached. It never creates one, so a test can hold a reference to
+// the very writer an eviction is about to detach.
 func (e *Engine) ExportArchiveWriterFor(
-	webhookID string,
+	targetID string,
 ) *ExportArchiveWriter {
 	e.dbTarget.mu.Lock()
 	defer e.dbTarget.mu.Unlock()
 
-	w, ok := e.dbTarget.writers[webhookID]
+	w, ok := e.dbTarget.writers[targetID]
 	if !ok {
 		return nil
 	}
@@ -585,26 +592,26 @@ func (e *Engine) ExportArchiveWriterFor(
 }
 
 // ExportHasArchiveWriter reports whether the database target
-// currently caches an archive writer for a webhook.
+// type currently caches an archive writer for a target.
 func (e *Engine) ExportHasArchiveWriter(
-	webhookID string,
+	targetID string,
 ) bool {
 	e.dbTarget.mu.Lock()
 	defer e.dbTarget.mu.Unlock()
 
-	_, ok := e.dbTarget.writers[webhookID]
+	_, ok := e.dbTarget.writers[targetID]
 
 	return ok
 }
 
 // ExportArchiveHandleOpen reports whether the cached archive
-// writer for a webhook holds an open database handle. It
+// writer for a target holds an open database handle. It
 // returns false when no writer is cached.
 func (e *Engine) ExportArchiveHandleOpen(
-	webhookID string,
+	targetID string,
 ) bool {
 	e.dbTarget.mu.Lock()
-	w, ok := e.dbTarget.writers[webhookID]
+	w, ok := e.dbTarget.writers[targetID]
 	e.dbTarget.mu.Unlock()
 
 	if !ok {
@@ -618,12 +625,12 @@ func (e *Engine) ExportArchiveHandleOpen(
 }
 
 // ExportEnsureArchiveWriter creates (if needed) and returns the
-// archive file path of the cached writer for a webhook, so a
+// archive file path of the cached writer for a target, so a
 // test can prime the registry the way a delivery would.
 func (e *Engine) ExportEnsureArchiveWriter(
-	webhookID string,
+	targetID string,
 ) (string, error) {
-	w, err := e.dbTarget.writerFor(webhookID)
+	w, err := e.dbTarget.writerFor(targetID)
 	if err != nil {
 		return "", err
 	}
@@ -631,14 +638,14 @@ func (e *Engine) ExportEnsureArchiveWriter(
 	return w.path, nil
 }
 
-// ExportSweepWriterFor takes a webhook's registry writer exactly
+// ExportSweepWriterFor takes a target's registry writer exactly
 // as the idle sweep does, reporting whether the sweep had to
 // create the entry. It lets a test drive the registry through the
 // sweep's own entry point instead of choreographing goroutines.
 func (e *Engine) ExportSweepWriterFor(
-	webhookID string,
+	targetID string,
 ) (*ExportArchiveWriter, bool, error) {
-	w, created, err := e.dbTarget.sweepWriterFor(webhookID)
+	w, created, err := e.dbTarget.sweepWriterFor(targetID)
 	if err != nil {
 		return nil, false, err
 	}
@@ -649,9 +656,9 @@ func (e *Engine) ExportSweepWriterFor(
 // ExportReleaseSweepWriter releases a sweep-created registry entry
 // exactly as a finished sweep does.
 func (e *Engine) ExportReleaseSweepWriter(
-	webhookID string, w *ExportArchiveWriter,
+	targetID string, w *ExportArchiveWriter,
 ) {
-	e.dbTarget.releaseSweepWriter(webhookID, w.w)
+	e.dbTarget.releaseSweepWriter(targetID, w.w)
 }
 
 // NewTestArchiveSweeper builds an ArchiveSweeper backed by the

internal/delivery/metrics_test.go

@@ -35,9 +35,8 @@ const (
 )
 
 // mIsolate gives the setup's engine a metric set registered on a
-// private registry. The process-wide collectors are moved by every
-// other delivery test running in parallel, so exact assertions are
-// only possible against a registry this test owns.
+// registry this test holds, so its exact assertions can gather from
+// it.
 func mIsolate(
 	t *testing.T, s iSetup,
 ) *prometheus.Registry {

internal/delivery/redirect_test.go

@@ -375,6 +375,7 @@ func TestApplyRequestHeaders_ReportsOriginScopedNames(t *testing.T) {
 				"Content-Type":  testContentType,
 			},
 		},
+		"webhooker/dev",
 	)
 
 	assert.Equal(t,

internal/delivery/ssrf.go

@@ -25,8 +25,16 @@ var (
 	errNoIPs      = errors.New(
 		"hostname resolved to no IP addresses",
 	)
-	errBlockedIP = errors.New(
-		"blocked private, reserved or cloud metadata address",
+	// ErrBlockedPrivateOrReservedIP reports an address in the
+	// default blocklist's private and reserved ranges,
+	// blockedNetworks.
+	ErrBlockedPrivateOrReservedIP = errors.New(
+		"blocked private or reserved address",
+	)
+	// errBlockedPublicMetadata reports a public address on the
+	// default blocklist, one in blockedPublicNetworks.
+	errBlockedPublicMetadata = errors.New(
+		"blocked cloud metadata address",
 	)
 	errBlockedMetadata = errors.New(
 		"blocked link-local or cloud instance metadata " +
@@ -37,22 +45,32 @@ var (
 	)
 )
 
-// blockedNetworks is the default blocklist: the private and
-// reserved IP ranges, plus the public cloud metadata addresses,
-// that are blocked to prevent SSRF attacks. An operator can
-// permit specific blocks out of this set with
-// ALLOWED_EGRESS_CIDRS; see Guard.
+// blockedNetworks and blockedPublicNetworks together are the
+// default blocklist: the private and reserved IP ranges, plus
+// the public cloud metadata addresses, that are blocked to
+// prevent SSRF attacks. An operator can permit specific blocks
+// out of this set with ALLOWED_EGRESS_CIDRS; see Guard.
 //
-// A public address belongs on the default blocklist only if it
-// hands credentials, user data or bootstrap material to whatever
-// can reach it, without the caller presenting anything. A
-// provider's other public addresses are not refused, since
-// reaching them can be legitimate and no list of them could be
-// complete.
+// blockedNetworks holds the private and reserved IP ranges.
 //
 //nolint:gochecknoglobals // package-level network list is appropriate here
 var blockedNetworks []*net.IPNet
 
+// blockedPublicNetworks holds the default blocklist's public
+// addresses, kept apart from blockedNetworks so that they are
+// refused as cloud metadata addresses, never as private or
+// reserved ones.
+//
+// A public address belongs on the default blocklist only if it
+// hands credentials, user data or bootstrap material to whatever
+// can reach it, without the caller presenting anything; it goes
+// in this list. A provider's other public addresses are not
+// refused, since reaching them can be legitimate and no list of
+// them could be complete.
+//
+//nolint:gochecknoglobals // package-level network list is appropriate here
+var blockedPublicNetworks []*net.IPNet
+
 // alwaysBlockedNetworks are the ranges no configuration can
 // open: the link-local blocks and the cloud instance metadata
 // endpoints that live outside them. Reaching one is credential
@@ -88,8 +106,8 @@ var blockedNetworks []*net.IPNet
 // when it clears both halves. Nothing in this list can be
 // reopened, so putting a public address here leaves the operator
 // no escape hatch at all — the condition ALLOWED_EGRESS_CIDRS
-// exists to remove. Default-block it in blockedNetworks instead,
-// which an allowlist can override.
+// exists to remove. Default-block it in blockedPublicNetworks
+// instead, which an allowlist can override.
 //
 // This is a criterion, not an enumeration of every metadata
 // address in existence.
@@ -130,6 +148,9 @@ func init() {
 		"::1/128",
 		"fc00::/7",
 		"fe80::/10",
+	})
+
+	blockedPublicNetworks = mustParseCIDRs([]string{
 		// Azure WireServer, a public address that serves VM credentials.
 		"168.63.129.16/32",
 	})
@@ -225,13 +246,6 @@ func matchesAny(networks []*net.IPNet, ip net.IP) bool {
 	return false
 }
 
-// isBlockedIP checks whether an IP address falls within
-// the default blocklist, before any operator allowlist is
-// considered.
-func isBlockedIP(ip net.IP) bool {
-	return matchesAny(blockedNetworks, ip)
-}
-
 // Guard makes every SSRF decision in the process.
 //
 // It holds the operator's ALLOWED_EGRESS_CIDRS allowlist and
@@ -332,7 +346,8 @@ func (g *Guard) allows(ip net.IP) bool {
 //     consulted, so no configured CIDR reaches link-local or a
 //     cloud metadata endpoint at a non-public address.
 //  2. The allowlist is consulted next, so a listed private
-//     network becomes reachable.
+//     network, or a listed public address on the default
+//     blocklist, becomes reachable.
 //  3. Everything else keeps the default blocklist's answer.
 func (g *Guard) checkIP(ip net.IP) error {
 	if matchesAny(alwaysBlockedNetworks, ip) {
@@ -345,9 +360,15 @@ func (g *Guard) checkIP(ip net.IP) error {
 		return nil
 	}
 
-	if isBlockedIP(ip) {
+	if matchesAny(blockedNetworks, ip) {
 		return fmt.Errorf(
-			"target IP %s: %w", ip, errBlockedIP,
+			"target IP %s: %w", ip, ErrBlockedPrivateOrReservedIP,
+		)
+	}
+
+	if matchesAny(blockedPublicNetworks, ip) {
+		return fmt.Errorf(
+			"target IP %s: %w", ip, errBlockedPublicMetadata,
 		)
 	}
 

internal/delivery/ssrf_allowlist_test.go

@@ -23,6 +23,10 @@ const (
 	metadataIP  = "169.254.169.254"
 	metadataURL = "http://" + metadataIP + "/latest/meta-data/"
 
+	// linkLocalIPv4 is the IPv4 link-local block, which holds
+	// metadataIP.
+	linkLocalIPv4 = "169.254.0.0/16"
+
 	// loopbackHookURL is a target on this host: blocked by
 	// default, reachable only once an operator allowlists
 	// loopback.
@@ -237,7 +241,7 @@ func linkLocalRefusedCases() []metadataAlwaysRefusedCase {
 		},
 		{
 			name:   "whole link-local block",
-			allow:  "169.254.0.0/16",
+			allow:  linkLocalIPv4,
 			target: metadataURL,
 		},
 		{
@@ -412,6 +416,9 @@ func TestGuardAllowlist_AzureWireServerReopenable(t *testing.T) {
 		"WireServer must be refused by the default blocklist, "+
 			"which an allowlist can override",
 	)
+	require.NotErrorIs(t, err, delivery.ErrBlockedPrivateOrReservedIP,
+		"WireServer is public, not private or reserved",
+	)
 
 	assertDialRefused(t, defaultGuard, target)
 
@@ -496,7 +503,7 @@ func TestAlwaysBlockedNetworks_PinnedSet(t *testing.T) {
 	want := []string{
 		// IPv4 link-local: the 169.254.169.254 metadata
 		// service on AWS, Azure and others.
-		"169.254.0.0/16",
+		linkLocalIPv4,
 		// IPv6 link-local.
 		"fe80::/10",
 		// AWS IPv6 IMDS, inside the ULA space an operator may
@@ -526,6 +533,90 @@ func TestAlwaysBlockedNetworks_PinnedSet(t *testing.T) {
 	assert.Equal(t, want, got)
 }
 
+// TestDefaultBlocklist_PinnedSet pins each list of the default
+// blocklist on its own, the private and reserved ranges in
+// blockedNetworks and the public addresses in
+// blockedPublicNetworks, so moving an entry from one list to the
+// other fails it. For the first address of each entry it then
+// checks that the default guard refuses it, and that listing the
+// entry in ALLOWED_EGRESS_CIDRS opens it unless the unconditional
+// set holds that address.
+func TestDefaultBlocklist_PinnedSet(t *testing.T) {
+	t.Parallel()
+
+	// public marks an entry of blockedPublicNetworks; every other
+	// entry belongs in blockedNetworks.
+	tests := []struct {
+		cidr       string
+		public     bool
+		reopenable bool
+	}{
+		{cidr: "127.0.0.0/8", reopenable: true},
+		{cidr: "10.0.0.0/8", reopenable: true},
+		{cidr: "172.16.0.0/12", reopenable: true},
+		{cidr: "192.168.0.0/16", reopenable: true},
+		{cidr: linkLocalIPv4, reopenable: false},
+		{cidr: "0.0.0.0/8", reopenable: true},
+		{cidr: "100.64.0.0/10", reopenable: true},
+		{cidr: "192.0.0.0/24", reopenable: true},
+		{cidr: "192.0.2.0/24", reopenable: true},
+		{cidr: "198.18.0.0/15", reopenable: true},
+		{cidr: "198.51.100.0/24", reopenable: true},
+		{cidr: "203.0.113.0/24", reopenable: true},
+		{cidr: "224.0.0.0/4", reopenable: true},
+		{cidr: "240.0.0.0/4", reopenable: true},
+		{cidr: "::1/128", reopenable: true},
+		{cidr: "fc00::/7", reopenable: true},
+		{cidr: "fe80::/10", reopenable: false},
+		{cidr: "168.63.129.16/32", public: true, reopenable: true},
+	}
+
+	wantPrivate := make([]string, 0, len(tests))
+	wantPublic := make([]string, 0, len(tests))
+
+	for _, tt := range tests {
+		if tt.public {
+			wantPublic = append(wantPublic, tt.cidr)
+		} else {
+			wantPrivate = append(wantPrivate, tt.cidr)
+		}
+	}
+
+	gotPrivate := make([]string, 0, len(tests))
+	for _, n := range delivery.ExportBlockedNetworks() {
+		gotPrivate = append(gotPrivate, n.String())
+	}
+
+	gotPublic := make([]string, 0, len(tests))
+	for _, n := range delivery.ExportBlockedPublicNetworks() {
+		gotPublic = append(gotPublic, n.String())
+	}
+
+	assert.ElementsMatch(t, wantPrivate, gotPrivate, "blockedNetworks")
+	assert.ElementsMatch(t, wantPublic, gotPublic, "blockedPublicNetworks")
+
+	for _, tt := range tests {
+		t.Run(tt.cidr, func(t *testing.T) {
+			t.Parallel()
+
+			prefix := netip.MustParsePrefix(tt.cidr)
+			ip := net.IP(prefix.Addr().AsSlice())
+
+			require.Error(t,
+				delivery.NewTestGuard().ExportCheckIP(ip),
+				"the default guard must refuse %s", ip,
+			)
+
+			err := delivery.NewTestGuard(prefix).ExportCheckIP(ip)
+			if tt.reopenable {
+				assert.NoError(t, err, "listing %s must open it", tt.cidr)
+			} else {
+				assert.Error(t, err, "listing %s must not open it", tt.cidr)
+			}
+		})
+	}
+}
+
 // requireLoopback fails the test unless rawURL's host is a
 // loopback address, so the allowlist test cannot silently stop
 // exercising a blocked range.

internal/delivery/ssrf_test.go

@@ -10,7 +10,7 @@ import (
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
-func TestIsBlockedIP_PrivateRanges(t *testing.T) {
+func TestGuardCheckIP_PrivateRanges(t *testing.T) {
 	t.Parallel()
 
 	tests := []struct {
@@ -56,12 +56,14 @@ func TestIsBlockedIP_PrivateRanges(t *testing.T) {
 				"failed to parse IP %s", tt.ip,
 			)
 
+			refused := delivery.NewTestGuard().ExportCheckIP(ip) != nil
+
 			assert.Equal(t,
 				tt.blocked,
-				delivery.ExportIsBlockedIP(ip),
-				"isBlockedIP(%s) = %v, want %v",
+				refused,
+				"default guard refuses %s = %v, want %v",
 				tt.ip,
-				delivery.ExportIsBlockedIP(ip),
+				refused,
 				tt.blocked,
 			)
 		})

internal/delivery/target_database.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"path/filepath"
+	"strings"
 	"sync"
 	"time"
 
@@ -11,22 +12,75 @@ import (
 	"sneak.berlin/go/webhooker/internal/database"
 )
 
-// databaseTarget is a no-retry target that archives the
-// full inbound event into a per-webhook archive SQLite file,
-// separate from the per-webhook event database. The event is
-// already persisted in the per-webhook event DB by the time
-// delivery runs; the database target additionally writes a
-// durable long-term copy into archive-{webhookID}.db and then
-// records a single attempt whose outcome reflects whether the
-// archive write succeeded. See archiveWriter for the
-// close/reopen, auto-recreate, and expiry semantics.
+// archiveNameMaxLen is how many characters of a webhook or target
+// name an archive file name keeps.
+const archiveNameMaxLen = 40
+
+// databaseTarget is a no-retry target that archives the full
+// inbound event into the target's own archive SQLite file, separate
+// from the per-webhook event database. The event is already
+// persisted in the per-webhook event DB by the time delivery runs;
+// the database target additionally writes a durable long-term copy
+// into the file ArchiveFileName names and then records a single
+// attempt whose outcome reflects whether the archive write
+// succeeded. See archiveWriter for the close/reopen, auto-recreate,
+// and expiry semantics.
 type databaseTarget struct {
 	eng *Engine
 
+	// writers holds one archive writer per database target, keyed
+	// by target ID.
 	mu      sync.Mutex
 	writers map[string]*archiveWriter
 }
 
+// ArchiveFileName returns the file name of a database target's
+// archive: archive-WEBHOOKNAME-TARGETNAME-TARGETID.db, with both
+// names passed through archiveNamePart. The target ID keeps the
+// name unique when two targets' names come out the same.
+func ArchiveFileName(webhookName, targetName, targetID string) string {
+	return "archive-" + archiveNamePart(webhookName) + "-" +
+		archiveNamePart(targetName) + "-" + targetID + ".db"
+}
+
+// archiveNamePart makes a webhook or target name safe to put in a
+// file name. It is lowercased; ASCII letters and digits are kept,
+// every other run of characters becomes a single "-", and no "-" is
+// left at either end. It is cut to archiveNameMaxLen characters, and
+// a name with nothing left is "unnamed".
+func archiveNamePart(name string) string {
+	var b strings.Builder
+
+	dash := false
+
+	for _, r := range strings.ToLower(name) {
+		if (r < 'a' || r > 'z') && (r < '0' || r > '9') {
+			dash = b.Len() > 0
+
+			continue
+		}
+
+		if dash {
+			b.WriteByte('-')
+
+			dash = false
+		}
+
+		b.WriteRune(r)
+	}
+
+	part := b.String()
+	if len(part) > archiveNameMaxLen {
+		part = strings.TrimRight(part[:archiveNameMaxLen], "-")
+	}
+
+	if part == "" {
+		return "unnamed"
+	}
+
+	return part
+}
+
 // Deliver implements Target. It archives the event, then
 // records one successful attempt and marks the delivery
 // delivered. An archiving error fails the delivery: the
@@ -92,7 +146,7 @@ func (t *databaseTarget) Deliver(
 	)
 }
 
-// archive writes the full event as a row into the webhook's
+// archive writes the full event as a row into the target's
 // archive database, honouring the optional per-target expiry
 // parsed from the target config JSON.
 func (t *databaseTarget) archive(d *database.Delivery) error {
@@ -106,7 +160,7 @@ func (t *databaseTarget) archive(d *database.Delivery) error {
 		return err
 	}
 
-	w, err := t.writerFor(webhookID)
+	w, err := t.writerFor(d.TargetID)
 	if err != nil {
 		return err
 	}
@@ -124,30 +178,31 @@ func (t *databaseTarget) archive(d *database.Delivery) error {
 	return w.write(row, expiry)
 }
 
-// writerFor returns the archiveWriter for a webhook, creating
-// and caching it on first use. Each webhook has one writer so
-// its close/reopen debounce state is shared across concurrent
-// deliveries. The archive file lives beside the per-webhook
-// event database in the data directory.
+// writerFor returns the archive writer for a database target,
+// creating and caching it on first use. Each target has one writer
+// so its close/reopen debounce state is shared across concurrent
+// deliveries, and so a rename and the idle sweep take the same lock
+// as its writes.
 func (t *databaseTarget) writerFor(
-	webhookID string,
+	targetID string,
 ) (*archiveWriter, error) {
-	path, err := t.archivePath(webhookID)
-	if err != nil {
-		return nil, err
-	}
-
 	t.mu.Lock()
 	defer t.mu.Unlock()
 
-	if t.writers == nil {
-		t.writers = make(map[string]*archiveWriter)
-	}
-
-	w, ok := t.writers[webhookID]
+	w, ok := t.writers[targetID]
 	if !ok {
-		w = newArchiveWriter(path, t.eng.log)
-		t.writers[webhookID] = w
+		var err error
+
+		w, err = t.newWriter(targetID)
+		if err != nil {
+			return nil, err
+		}
+
+		if t.writers == nil {
+			t.writers = make(map[string]*archiveWriter)
+		}
+
+		t.writers[targetID] = w
 	}
 
 	// A delivery claims the entry: even if the idle sweep created
@@ -159,40 +214,39 @@ func (t *databaseTarget) writerFor(
 }
 
 // sweepWriterFor returns the archive writer the idle sweep should
-// prune a webhook through, together with whether the sweep itself
-// created the registry entry.
+// prune a target's archive through, together with whether the sweep
+// itself created the registry entry.
 //
 // The sweep must route its prune through the registered writer so
 // the writer's mutex orders it against concurrent writes, but it
 // must never leave a registry entry behind: a sweep that ran
-// concurrently with the webhook's deletion would otherwise
+// concurrently with the target's deletion would otherwise
 // re-create an entry that nothing will ever evict again, which is
 // exactly the leak eviction exists to prevent. An entry the sweep
 // creates is therefore marked sweep-owned and handed back to
 // releaseSweepWriter when the sweep is done.
 func (t *databaseTarget) sweepWriterFor(
-	webhookID string,
+	targetID string,
 ) (*archiveWriter, bool, error) {
-	path, err := t.archivePath(webhookID)
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	w, ok := t.writers[targetID]
+	if ok {
+		return w, false, nil
+	}
+
+	w, err := t.newWriter(targetID)
 	if err != nil {
 		return nil, false, err
 	}
 
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
 	if t.writers == nil {
 		t.writers = make(map[string]*archiveWriter)
 	}
 
-	w, ok := t.writers[webhookID]
-	if ok {
-		return w, false, nil
-	}
-
-	w = newArchiveWriter(path, t.eng.log)
 	w.sweepOwned = true
-	t.writers[webhookID] = w
+	t.writers[targetID] = w
 
 	return w, true, nil
 }
@@ -209,57 +263,95 @@ func (t *databaseTarget) sweepWriterFor(
 // delivery that adopted the writer keeps a registered, evictable
 // one.
 func (t *databaseTarget) releaseSweepWriter(
-	webhookID string, w *archiveWriter,
+	targetID string, w *archiveWriter,
 ) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 
-	cur, ok := t.writers[webhookID]
+	cur, ok := t.writers[targetID]
 	if !ok || cur != w || !cur.sweepOwned {
 		return
 	}
 
-	delete(t.writers, webhookID)
+	delete(t.writers, targetID)
 }
 
-// archivePath returns the archive file path for a webhook: it
-// lives beside the per-webhook event database in the data
-// directory. It does not touch the filesystem.
-func (t *databaseTarget) archivePath(
-	webhookID string,
-) (string, error) {
+// newWriter builds the writer for a database target's archive. The
+// file lives beside the webhook's event database in the data
+// directory and is named for the webhook and the target as the main
+// database has them now; from then on only rename changes the name
+// the writer uses. It does not touch the archive file.
+func (t *databaseTarget) newWriter(
+	targetID string,
+) (*archiveWriter, error) {
 	if t.eng.dbManager == nil {
-		return "", errArchiveNoDataDir
+		return nil, errArchiveNoDataDir
 	}
 
-	dir := filepath.Dir(t.eng.dbManager.DBPath(webhookID))
+	var target database.Target
 
-	return filepath.Join(
-		dir, fmt.Sprintf("archive-%s.db", webhookID),
-	), nil
+	err := t.eng.database.DB().
+		Preload("Webhook").
+		First(&target, "id = ?", targetID).Error
+	if err != nil {
+		return nil, fmt.Errorf(
+			"loading database target %s: %w", targetID, err,
+		)
+	}
+
+	dir := filepath.Dir(t.eng.dbManager.DBPath(target.WebhookID))
+	name := ArchiveFileName(
+		target.Webhook.Name, target.Name, target.ID,
+	)
+
+	w := newArchiveWriter(filepath.Join(dir, name), t.eng.log)
+	w.webhookID = target.WebhookID
+
+	return w, nil
 }
 
-// evict drops a webhook's archive writer from the registry and
-// closes its handle, so a deleted webhook does not leave a
-// writer (and an open archive handle within its debounce
-// window) alive for the process lifetime.
+// rename moves a database target's archive file to the name for
+// webhookName and targetName. It goes through the target's writer,
+// so the move holds the lock that writes and the idle sweep take,
+// and later writes use the new name.
+//
+// The writer is created if there is none, and it stays cached. The
+// handlers rename before they save the new name, so until the save
+// the main database still has the old one; a delivery in that window
+// must find this writer rather than build one from the old name.
+func (t *databaseTarget) rename(
+	targetID, webhookName, targetName string,
+) error {
+	w, err := t.writerFor(targetID)
+	if err != nil {
+		return err
+	}
+
+	return w.rename(ArchiveFileName(webhookName, targetName, targetID))
+}
+
+// evict drops a database target's archive writer from the registry
+// and closes its handle, so a deleted target does not leave a
+// writer (and an open archive handle within its debounce window)
+// alive for the process lifetime.
 //
 // The map entry is removed under the registry lock, which is
 // then released before the handle is closed under the writer's
 // own lock: that ordering keeps the registry available to other
-// webhooks while an in-flight write on this one drains, and
+// targets while an in-flight write on this one drains, and
 // closing under the writer's lock means eviction can never race
 // a write.
 //
-// Eviction is idempotent and silent for a webhook with no
-// writer, which is the common case: a webhook with no database
-// target never creates one. It never deletes the archive file.
-func (t *databaseTarget) evict(webhookID string) {
+// Eviction is idempotent and silent for a target with no writer,
+// which is the common case: only a database target that has
+// received an event or been renamed has one. It never deletes the
+// archive file.
+func (t *databaseTarget) evict(targetID string) {
 	t.mu.Lock()
 
-	w, ok := t.writers[webhookID]
+	w, ok := t.writers[targetID]
 	if ok {
-		delete(t.writers, webhookID)
+		delete(t.writers, targetID)
 	}
 
 	t.mu.Unlock()
@@ -272,13 +364,41 @@ func (t *databaseTarget) evict(webhookID string) {
 
 	t.eng.log.Info(
 		"evicted archive writer",
-		"webhook_id", webhookID,
+		"target_id", targetID,
 		"path", w.path,
 	)
 }
 
+// evictWebhook evicts, exactly as evict does, the writer of every
+// database target of a webhook.
+func (t *databaseTarget) evictWebhook(webhookID string) {
+	t.mu.Lock()
+
+	var gone []*archiveWriter
+
+	for targetID, w := range t.writers {
+		if w.webhookID == webhookID {
+			delete(t.writers, targetID)
+
+			gone = append(gone, w)
+		}
+	}
+
+	t.mu.Unlock()
+
+	for _, w := range gone {
+		w.evict()
+
+		t.eng.log.Info(
+			"evicted archive writer",
+			"webhook_id", webhookID,
+			"path", w.path,
+		)
+	}
+}
+
 // evictAll evicts every cached archive writer, exactly as evict
-// does for one webhook. The engine calls it at shutdown, once its
+// does for one target. The engine calls it at shutdown, once its
 // workers have returned. Closing the last handle on an archive
 // moves the contents of its -wal into the .db and removes the
 // -wal, so a clean stop leaves each archive as a single file.
@@ -295,38 +415,25 @@ func (t *databaseTarget) evictAll() {
 	}
 }
 
-// sweepWebhook prunes one webhook's archive of rows older than
-// expiry, without requiring a write. It returns nil (nothing to
-// do) when the archive file does not exist, so a sweep never
-// creates an archive for a webhook that has a database target
-// but has never received an event.
+// sweepArchive prunes one database target's archive of rows older
+// than expiry, without requiring a write. A missing archive file is
+// left missing (see sweepExpired), so a sweep never creates an
+// archive for a target that has never received an event.
 //
 // It also never leaves a registry entry behind: an entry it had
 // to create to reach the writer's mutex is released again once
-// the prune is done, so a sweep racing a webhook deletion cannot
+// the prune is done, so a sweep racing a target deletion cannot
 // resurrect the writer the eviction just dropped.
-func (t *databaseTarget) sweepWebhook(
-	webhookID string, expiry time.Duration,
+func (t *databaseTarget) sweepArchive(
+	targetID string, expiry time.Duration,
 ) error {
-	path, err := t.archivePath(webhookID)
-	if err != nil {
-		return err
-	}
-
-	// Check before taking a writer at all: a webhook whose
-	// archive has never been created gets no writer, no handle,
-	// and no file.
-	if !fileExists(path) {
-		return nil
-	}
-
-	w, created, err := t.sweepWriterFor(webhookID)
+	w, created, err := t.sweepWriterFor(targetID)
 	if err != nil {
 		return err
 	}
 
 	if created {
-		defer t.releaseSweepWriter(webhookID, w)
+		defer t.releaseSweepWriter(targetID, w)
 	}
 
 	return w.sweepExpired(expiry)

internal/delivery/target_database_archive.go

@@ -4,8 +4,10 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io/fs"
 	"log/slog"
 	"os"
+	"path/filepath"
 	"sync"
 	"time"
 
@@ -41,7 +43,7 @@ const (
 
 var (
 	// errArchiveMissingWebhookID is returned when an event to
-	// archive has no webhook id to key its archive file on.
+	// archive has no webhook id to record in its archive row.
 	errArchiveMissingWebhookID = errors.New(
 		"cannot archive event without a webhook id",
 	)
@@ -61,13 +63,19 @@ var (
 	)
 
 	// errArchiveWriterEvicted is returned when a writer that has
-	// been evicted (its webhook was deleted, or its last database
-	// target was removed) is used again. An evicted writer is no
-	// longer in the registry, so reopening its file would leak a
-	// handle nothing owns.
+	// been evicted (its target or its webhook was deleted) is used
+	// again. An evicted writer is no longer in the registry, so
+	// reopening its file would leak a handle nothing owns.
 	errArchiveWriterEvicted = errors.New(
 		"archive writer has been evicted",
 	)
+
+	// ErrArchiveNameTaken is returned when an archive cannot be
+	// renamed because a file already has the new name. That file may
+	// be an archive with rows of its own, so it is never replaced.
+	ErrArchiveNameTaken = errors.New(
+		"a file already has the archive's new name",
+	)
 )
 
 // databaseTargetConfig is the optional per-target JSON config
@@ -80,7 +88,7 @@ type databaseTargetConfig struct {
 }
 
 // archivedEvent is one fully captured webhook event stored in a
-// per-webhook archive database for long-term retention. It is a
+// database target's archive for long-term retention. It is a
 // self-contained copy — independent of the per-webhook event
 // database, which may prune events under its own retention.
 type archivedEvent struct {
@@ -170,8 +178,8 @@ func ValidateArchiveExpiry(expiry string) error {
 	return nil
 }
 
-// archiveWriter owns one per-webhook archive SQLite file. It
-// serialises writes, and after each write closes and reopens
+// archiveWriter owns one database target's archive SQLite file.
+// It serialises writes, and after each write closes and reopens
 // the file (debounced to at most once per debounce window) so
 // an operator can move the file away for offline archiving. The
 // next write recreates a moved or removed file, because the
@@ -187,16 +195,21 @@ type archiveWriter struct {
 	reopens    int
 
 	// evicted marks a writer that has been removed from the
-	// per-webhook registry. Its handle is closed and it must
-	// never open the file again: nothing holds it any more, so a
-	// reopen would leak the handle for the process lifetime.
+	// registry. Its handle is closed and it must never open the
+	// file again: nothing holds it any more, so a reopen would
+	// leak the handle for the process lifetime.
 	evicted bool
 
+	// webhookID is the webhook the archive's target belongs to,
+	// so deleting the webhook can find its writers. It is set
+	// when the writer is created and never changes.
+	webhookID string
+
 	// sweepOwned marks a registry entry that the idle sweep
-	// created because no writer was cached for the webhook. The
+	// created because no writer was cached for the target. The
 	// sweep removes such an entry again when it is done, so a
 	// sweep can never leave — or resurrect — a registry entry
-	// for a webhook that has been deleted. A delivery that adopts
+	// for a target that has been deleted. A delivery that adopts
 	// the writer clears the flag, handing the entry to the
 	// registry proper.
 	//
@@ -385,11 +398,78 @@ func (w *archiveWriter) sweepExpired(expiry time.Duration) error {
 	return nil
 }
 
+// rename gives the archive file a new name in the same directory,
+// and the writer uses the file under that name from now on. The
+// handle is closed first, which folds the -wal into the .db; any
+// -wal or -shm still beside the file (left by a crash) is moved with
+// it, because SQLite finds them by name. A missing file is not an
+// error: the operator may have moved it away, and the next write
+// creates it under the new name.
+//
+// If a file already has the new name, nothing is moved and the
+// error is ErrArchiveNameTaken. If one file fails to move, those
+// already moved are moved back before the error is returned, so the
+// archive is never split across two names.
+func (w *archiveWriter) rename(name string) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	if w.evicted {
+		return fmt.Errorf(
+			"%w: %s", errArchiveWriterEvicted, w.path,
+		)
+	}
+
+	path := filepath.Join(filepath.Dir(w.path), name)
+	if path == w.path {
+		return nil
+	}
+
+	suffixes := []string{"", "-wal", "-shm"}
+
+	for _, suffix := range suffixes {
+		if fileExists(path + suffix) {
+			return fmt.Errorf(
+				"%w: %s", ErrArchiveNameTaken, name+suffix,
+			)
+		}
+	}
+
+	w.close()
+
+	for i, suffix := range suffixes {
+		err := os.Rename(w.path+suffix, path+suffix)
+		if err == nil || errors.Is(err, fs.ErrNotExist) {
+			continue
+		}
+
+		for _, moved := range suffixes[:i] {
+			backErr := os.Rename(path+moved, w.path+moved)
+			if backErr != nil && !errors.Is(backErr, fs.ErrNotExist) {
+				w.log.Error(
+					"failed to move archive file back",
+					"from", path+moved,
+					"to", w.path+moved,
+					"error", backErr,
+				)
+			}
+		}
+
+		return fmt.Errorf(
+			"renaming archive %s to %s: %w", w.path+suffix, path+suffix, err,
+		)
+	}
+
+	w.path = path
+
+	return nil
+}
+
 // evict closes the writer's handle and marks it unusable. It is
-// called when the writer leaves the registry, either because the
-// webhook was deleted or because its last database target was
-// removed. The archive FILE is deliberately left on disk: it is
-// long-term storage an operator may still want.
+// called when the writer leaves the registry, because its target
+// or its webhook was deleted, or at shutdown. The archive FILE is
+// deliberately left on disk: it is long-term storage an operator
+// may still want.
 func (w *archiveWriter) evict() {
 	w.mu.Lock()
 	defer w.mu.Unlock()

internal/delivery/target_database_evict_test.go

@@ -17,85 +17,109 @@ import (
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
-// evictTestEngine builds an engine backed by a temporary data
-// directory and returns it along with that directory.
-func evictTestEngine(t *testing.T) (*delivery.Engine, string) {
+// deliverTo archives one event to a database target, leaving the
+// target's writer cached with its handle open.
+func deliverTo(
+	t *testing.T, env *archiveEnv, tgt *database.Target,
+) {
 	t.Helper()
 
-	dataDir := t.TempDir()
-
-	eng := delivery.NewTestEngineWithDB(
-		nil,
-		database.NewTestWebhookDBManager(dataDir),
-		archiveTestLogger(),
-		&http.Client{Timeout: 5 * time.Second},
-		1,
-	)
-
-	return eng, dataDir
-}
-
-// TestEvictWebhook_ClosesAndRemovesWriter proves that evicting
-// a webhook drops its archive writer from the registry and
-// closes the open archive handle, rather than leaving both
-// alive for the process lifetime.
-func TestEvictWebhook_ClosesAndRemovesWriter(t *testing.T) {
-	t.Parallel()
-
-	eng, dataDir := evictTestEngine(t)
-
 	webhookDB := testWebhookDB(t)
 	event := seedEvent(t, webhookDB, `{"archived":true}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
 
-	eng.ExportDeliverDatabase(webhookDB, d)
-
-	webhookID := event.WebhookID
-
-	require.True(
-		t, eng.ExportHasArchiveWriter(webhookID),
-		"a delivery should have cached an archive writer",
-	)
-	require.True(
-		t, eng.ExportArchiveHandleOpen(webhookID),
-		"the writer should hold an open handle after a write",
+	env.eng.ExportDeliverDatabase(
+		webhookDB, seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
 	)
+}
 
-	eng.EvictWebhook(webhookID)
+// TestEvictWebhook_ClosesAndRemovesWriter proves that evicting
+// a webhook drops the archive writers of its database targets
+// from the registry and closes their open handles, rather than
+// leaving them alive for the process lifetime, and leaves another
+// webhook's writer alone.
+func TestEvictWebhook_ClosesAndRemovesWriter(t *testing.T) {
+	t.Parallel()
 
-	assert.False(
-		t, eng.ExportHasArchiveWriter(webhookID),
-		"eviction should remove the registry entry",
-	)
-	assert.False(
-		t, eng.ExportArchiveHandleOpen(webhookID),
-		"eviction should close the archive handle",
-	)
+	env := setupArchiveTest(t)
+	first := env.seedDatabaseTarget(t, "")
+	second := env.addDatabaseTarget(t, first.WebhookID, "")
+	other := env.seedDatabaseTarget(t, "")
 
-	archivePath := filepath.Join(
-		dataDir, fmt.Sprintf("archive-%s.db", webhookID),
+	for _, tgt := range []*database.Target{first, second, other} {
+		deliverTo(t, env, tgt)
+
+		require.True(
+			t, env.eng.ExportArchiveHandleOpen(tgt.ID),
+			"the writer should hold an open handle after a write",
+		)
+	}
+
+	env.eng.EvictWebhook(first.WebhookID)
+
+	for _, tgt := range []*database.Target{first, second} {
+		assert.False(
+			t, env.eng.ExportHasArchiveWriter(tgt.ID),
+			"eviction should remove the registry entry",
+		)
+		assert.False(
+			t, env.eng.ExportArchiveHandleOpen(tgt.ID),
+			"eviction should close the archive handle",
+		)
+		assert.FileExists(
+			t, env.archivePath(tgt),
+			"eviction must not delete the archive file",
+		)
+	}
+
+	assert.True(
+		t, env.eng.ExportArchiveHandleOpen(other.ID),
+		"another webhook's writer must be left alone",
 	)
+}
+
+// TestEvictTarget_LeavesOtherTargets proves that evicting one
+// database target leaves the writer of another target of the same
+// webhook in place.
+func TestEvictTarget_LeavesOtherTargets(t *testing.T) {
+	t.Parallel()
+
+	env := setupArchiveTest(t)
+	doomed := env.seedDatabaseTarget(t, "")
+	kept := env.addDatabaseTarget(t, doomed.WebhookID, "")
+
+	deliverTo(t, env, doomed)
+	deliverTo(t, env, kept)
+
+	env.eng.EvictTarget(doomed.ID)
+
+	assert.False(t, env.eng.ExportHasArchiveWriter(doomed.ID))
 	assert.FileExists(
-		t, archivePath,
+		t, env.archivePath(doomed),
 		"eviction must not delete the archive file",
 	)
+	assert.True(
+		t, env.eng.ExportArchiveHandleOpen(kept.ID),
+		"the other target's writer must be left alone",
+	)
 }
 
 // TestEvictWebhook_UnknownWebhookIsNoOp proves eviction is safe
-// for the common case of a webhook that never had a database
-// target, and that repeating it does not panic.
+// for the common case of a webhook or target that never had an
+// archive writer, and that repeating it does not panic.
 func TestEvictWebhook_UnknownWebhookIsNoOp(t *testing.T) {
 	t.Parallel()
 
-	eng, _ := evictTestEngine(t)
+	env := setupArchiveTest(t)
 
 	assert.NotPanics(t, func() {
-		eng.EvictWebhook("no-such-webhook")
-		eng.EvictWebhook("no-such-webhook")
+		env.eng.EvictWebhook("no-such-webhook")
+		env.eng.EvictWebhook("no-such-webhook")
+		env.eng.EvictTarget("no-such-target")
+		env.eng.EvictTarget("no-such-target")
 	})
 
 	assert.False(
-		t, eng.ExportHasArchiveWriter("no-such-webhook"),
+		t, env.eng.ExportHasArchiveWriter("no-such-target"),
 		"eviction must not create a writer",
 	)
 }
@@ -289,17 +313,14 @@ func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
 ) {
 	t.Parallel()
 
-	eng, _ := evictTestEngine(t)
-
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"archived":true}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
 
 	// Prime the registry so the test can hold the very writer the
 	// eviction is about to detach.
-	eng.ExportDeliverDatabase(webhookDB, d)
+	deliverTo(t, env, tgt)
 
-	w := eng.ExportArchiveWriterFor(event.WebhookID)
+	w := env.eng.ExportArchiveWriterFor(tgt.ID)
 	require.NotNil(t, w)
 	require.True(t, w.HandleOpen())
 
@@ -309,7 +330,7 @@ func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
 	// eviction has to contend for the writer's mutex.
 	race.awaitFirstWrite()
 
-	eng.EvictWebhook(event.WebhookID)
+	env.eng.EvictWebhook(tgt.WebhookID)
 
 	sawEvicted, otherErr := race.wait()
 
@@ -324,41 +345,33 @@ func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
 			"been evicted",
 	)
 	assert.False(
-		t, eng.ExportHasArchiveWriter(event.WebhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"the registry entry must stay gone",
 	)
 }
 
 // TestEvictWebhook_LaterDeliveryRecreatesWriter proves eviction
-// does not break archiving for a webhook that is still alive: a
+// does not break archiving for a target that is still alive: a
 // subsequent delivery gets a brand new writer from the registry.
 // It says nothing about the evicted writer itself — that is what
 // TestEvictedWriter_WriteDoesNotReopenFile covers.
 func TestEvictWebhook_LaterDeliveryRecreatesWriter(t *testing.T) {
 	t.Parallel()
 
-	eng, _ := evictTestEngine(t)
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
 
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"archived":true}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+	deliverTo(t, env, tgt)
+	require.True(t, env.eng.ExportHasArchiveWriter(tgt.ID))
 
-	eng.ExportDeliverDatabase(webhookDB, d)
-	require.True(
-		t, eng.ExportHasArchiveWriter(event.WebhookID),
-	)
+	env.eng.EvictWebhook(tgt.WebhookID)
 
-	eng.EvictWebhook(event.WebhookID)
-
-	// A fresh delivery for the same webhook gets a brand new
+	// A fresh delivery for the same target gets a brand new
 	// writer from the registry, so archiving keeps working.
-	second := seedDatabaseTargetDelivery(
-		t, webhookDB, event, "",
-	)
-	eng.ExportDeliverDatabase(webhookDB, second)
+	deliverTo(t, env, tgt)
 
 	assert.True(
-		t, eng.ExportHasArchiveWriter(event.WebhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"a later delivery should recreate the writer",
 	)
 }
@@ -370,19 +383,16 @@ func TestEvictWebhook_LaterDeliveryRecreatesWriter(t *testing.T) {
 func TestEngineStop_WriteAfterStopIsRefused(t *testing.T) {
 	t.Parallel()
 
-	eng, _ := evictTestEngine(t)
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
 
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"archived":true}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+	deliverTo(t, env, tgt)
 
-	eng.ExportDeliverDatabase(webhookDB, d)
-
-	w := eng.ExportArchiveWriterFor(event.WebhookID)
+	w := env.eng.ExportArchiveWriterFor(tgt.ID)
 	require.NotNil(t, w)
 	require.True(t, w.HandleOpen())
 
-	require.NoError(t, eng.ExportStop(context.Background()))
+	require.NoError(t, env.eng.ExportStop(context.Background()))
 
 	err := w.Write(evictTestRow("ev-after-stop"), 0)
 
@@ -395,7 +405,7 @@ func TestEngineStop_WriteAfterStopIsRefused(t *testing.T) {
 		"a refused write must not reopen the archive",
 	)
 	assert.False(
-		t, eng.ExportHasArchiveWriter(event.WebhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"the stop should empty the registry",
 	)
 

internal/delivery/target_database_test.go

@@ -4,13 +4,12 @@ import (
 	"database/sql"
 	"fmt"
 	"log/slog"
-	"net/http"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 	"time"
 
-	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"gorm.io/driver/sqlite"
@@ -74,25 +73,18 @@ func removeArchiveFiles(t *testing.T, path string) {
 
 // TestDeliverDatabase_ArchivesEvent verifies that delivering to
 // a database target marks the delivery delivered and archives
-// the full event into a separate per-webhook archive file.
+// the full event into the target's own archive file.
 func TestDeliverDatabase_ArchivesEvent(t *testing.T) {
 	t.Parallel()
 
-	dataDir := t.TempDir()
-	dbMgr := database.NewTestWebhookDBManager(dataDir)
-
-	e := delivery.NewTestEngineWithDB(
-		nil, dbMgr,
-		archiveTestLogger(),
-		&http.Client{Timeout: 5 * time.Second},
-		1,
-	)
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
 
 	webhookDB := testWebhookDB(t)
 	event := seedEvent(t, webhookDB, `{"archived":true}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+	d := seedDatabaseTargetDelivery(t, webhookDB, event, tgt)
 
-	e.ExportDeliverDatabase(webhookDB, d)
+	env.eng.ExportDeliverDatabase(webhookDB, d)
 
 	var updated database.Delivery
 
@@ -105,8 +97,7 @@ func TestDeliverDatabase_ArchivesEvent(t *testing.T) {
 	)
 
 	archivePath := filepath.Join(
-		dataDir,
-		fmt.Sprintf("archive-%s.db", event.WebhookID),
+		env.dataDir, "archive-sweep-test-archive-"+tgt.ID+".db",
 	)
 	assert.FileExists(t, archivePath)
 
@@ -288,31 +279,31 @@ func TestParseArchiveExpiry(t *testing.T) {
 	}
 }
 
-// seedDatabaseTargetDelivery seeds a pending delivery for a
-// database target with the given config JSON and returns the
-// in-memory delivery the target handler is invoked with.
+// seedDatabaseTargetDelivery seeds a pending delivery of an event
+// to a database target and returns the in-memory delivery the
+// target handler is invoked with.
 func seedDatabaseTargetDelivery(
 	t *testing.T,
 	webhookDB *gorm.DB,
 	event database.Event,
-	config string,
+	tgt *database.Target,
 ) *database.Delivery {
 	t.Helper()
 
 	dlv := seedDelivery(
-		t, webhookDB, event.ID, uuid.New().String(),
+		t, webhookDB, event.ID, tgt.ID,
 		database.DeliveryStatusPending,
 	)
 
 	d := &database.Delivery{
 		EventID:  event.ID,
-		TargetID: dlv.TargetID,
+		TargetID: tgt.ID,
 		Status:   database.DeliveryStatusPending,
 		Event:    event,
 		Target: database.Target{
-			Name:   "test-db",
+			Name:   tgt.Name,
 			Type:   database.TargetTypeDatabase,
-			Config: config,
+			Config: tgt.Config,
 		},
 	}
 	d.ID = dlv.ID
@@ -330,22 +321,14 @@ func TestDeliverDatabase_ArchiveFailureFailsDelivery(
 ) {
 	t.Parallel()
 
-	dataDir := t.TempDir()
-
-	e := delivery.NewTestEngineWithDB(
-		nil, database.NewTestWebhookDBManager(dataDir),
-		archiveTestLogger(),
-		&http.Client{Timeout: 5 * time.Second},
-		1,
-	)
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, `{"expiry":"nonsense"}`)
 
 	webhookDB := testWebhookDB(t)
 	event := seedEvent(t, webhookDB, `{"archived":false}`)
-	d := seedDatabaseTargetDelivery(
-		t, webhookDB, event, `{"expiry":"nonsense"}`,
-	)
+	d := seedDatabaseTargetDelivery(t, webhookDB, event, tgt)
 
-	e.ExportDeliverDatabase(webhookDB, d)
+	env.eng.ExportDeliverDatabase(webhookDB, d)
 
 	var updated database.Delivery
 
@@ -373,10 +356,7 @@ func TestDeliverDatabase_ArchiveFailureFailsDelivery(
 	)
 
 	assert.NoFileExists(t,
-		filepath.Join(
-			dataDir,
-			fmt.Sprintf("archive-%s.db", event.WebhookID),
-		),
+		env.archivePath(tgt),
 		"no archive file should exist for a failed config",
 	)
 }
@@ -400,3 +380,290 @@ func TestValidateArchiveExpiry(t *testing.T) {
 		)
 	}
 }
+
+// TestArchiveFileName pins the archive file name and the rules
+// that make a webhook or target name safe to put in it.
+func TestArchiveFileName(t *testing.T) {
+	t.Parallel()
+
+	const id = "3f2a1c9e-8d4b-4c1a-9e2f-0a1b2c3d4e5f"
+
+	cases := []struct {
+		name    string
+		webhook string
+		target  string
+		want    string
+	}{
+		{
+			"plain names", "orders", "archive",
+			"archive-orders-archive-" + id + ".db",
+		},
+		{
+			"lowercased", "Orders", "Main Archive",
+			"archive-orders-main-archive-" + id + ".db",
+		},
+		{
+			"a run of other characters is one dash",
+			`a  /\..b`, "c__--d",
+			"archive-a-b-c-d-" + id + ".db",
+		},
+		{
+			"no dash at either end", "  --orders!! ", "(archive)",
+			"archive-orders-archive-" + id + ".db",
+		},
+		{
+			"path separators", "../../etc/passwd", "a/b",
+			"archive-etc-passwd-a-b-" + id + ".db",
+		},
+		{
+			"letters outside ASCII are dropped",
+			"Bestellungen Größe", "café",
+			"archive-bestellungen-gr-e-caf-" + id + ".db",
+		},
+		{
+			"nothing left is unnamed", "", "!!!",
+			"archive-unnamed-unnamed-" + id + ".db",
+		},
+		{
+			"cut to 40 characters", strings.Repeat("a", 50), "x",
+			"archive-" + strings.Repeat("a", 40) + "-x-" + id + ".db",
+		},
+		{
+			"no dash left by the cut",
+			strings.Repeat("a", 39) + " b", "x",
+			"archive-" + strings.Repeat("a", 39) + "-x-" + id + ".db",
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			assert.Equal(
+				t, tc.want,
+				delivery.ArchiveFileName(tc.webhook, tc.target, id),
+			)
+		})
+	}
+}
+
+// TestDeliverDatabase_EachTargetHasItsOwnArchive proves two
+// database targets of one webhook archive into separate files.
+func TestDeliverDatabase_EachTargetHasItsOwnArchive(t *testing.T) {
+	t.Parallel()
+
+	env := setupArchiveTest(t)
+	first := env.seedDatabaseTarget(t, "")
+	second := env.addDatabaseTarget(t, first.WebhookID, "")
+
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"n":1}`)
+
+	for _, tgt := range []*database.Target{first, second} {
+		env.eng.ExportDeliverDatabase(
+			webhookDB,
+			seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
+		)
+	}
+
+	require.NotEqual(
+		t, env.archivePath(first), env.archivePath(second),
+	)
+	assert.Equal(
+		t, []string{event.ID},
+		archivedEventIDs(t, env.archivePath(first)),
+	)
+	assert.Equal(
+		t, []string{event.ID},
+		archivedEventIDs(t, env.archivePath(second)),
+	)
+}
+
+// TestRename_MovesTheFile proves a rename moves the archive, rows
+// and all, and that later writes go to the new name.
+func TestRename_MovesTheFile(t *testing.T) {
+	t.Parallel()
+
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
+	oldPath := env.archivePath(tgt)
+
+	webhookDB := testWebhookDB(t)
+	first := seedEvent(t, webhookDB, `{"n":1}`)
+	env.eng.ExportDeliverDatabase(
+		webhookDB, seedDatabaseTargetDelivery(t, webhookDB, first, tgt),
+	)
+	require.FileExists(t, oldPath)
+
+	require.NoError(
+		t, env.eng.Rename(tgt.ID, "Orders", "Long Term"),
+	)
+
+	newPath := filepath.Join(
+		env.dataDir, "archive-orders-long-term-"+tgt.ID+".db",
+	)
+
+	assert.NoFileExists(t, oldPath)
+	assert.Equal(t, []string{first.ID}, archivedEventIDs(t, newPath))
+
+	second := seedEvent(t, webhookDB, `{"n":2}`)
+	env.eng.ExportDeliverDatabase(
+		webhookDB,
+		seedDatabaseTargetDelivery(t, webhookDB, second, tgt),
+	)
+
+	assert.ElementsMatch(
+		t, []string{first.ID, second.ID},
+		archivedEventIDs(t, newPath),
+	)
+	assert.NoFileExists(
+		t, oldPath, "a write after the rename must use the new name",
+	)
+}
+
+// TestRename_NeverReplacesAFile plants a file at the new name, once
+// the .db alone, once a lone -wal and once a lone -shm, and proves
+// each time that the rename is refused, the planted file survives,
+// and the archive keeps its name and its rows.
+func TestRename_NeverReplacesAFile(t *testing.T) {
+	t.Parallel()
+
+	for _, suffix := range archiveFileSuffixes() {
+		t.Run("planted .db"+suffix, func(t *testing.T) {
+			t.Parallel()
+
+			env := setupArchiveTest(t)
+			tgt := env.seedDatabaseTarget(t, "")
+			oldPath := env.archivePath(tgt)
+
+			webhookDB := testWebhookDB(t)
+			first := seedEvent(t, webhookDB, `{"n":1}`)
+			env.eng.ExportDeliverDatabase(
+				webhookDB,
+				seedDatabaseTargetDelivery(t, webhookDB, first, tgt),
+			)
+
+			newPath := filepath.Join(
+				env.dataDir, "archive-orders-long-term-"+tgt.ID+".db",
+			)
+			plantedPath := newPath + suffix
+			require.NoError(
+				t, os.WriteFile(plantedPath, []byte("planted"), 0o600),
+			)
+
+			require.ErrorIs(
+				t, env.eng.Rename(tgt.ID, "Orders", "Long Term"),
+				delivery.ErrArchiveNameTaken,
+			)
+
+			//nolint:gosec // reads the file the test planted under t.TempDir()
+			planted, err := os.ReadFile(plantedPath)
+			require.NoError(t, err)
+			assert.Equal(t, "planted", string(planted))
+
+			second := seedEvent(t, webhookDB, `{"n":2}`)
+			env.eng.ExportDeliverDatabase(
+				webhookDB,
+				seedDatabaseTargetDelivery(t, webhookDB, second, tgt),
+			)
+
+			assert.ElementsMatch(
+				t, []string{first.ID, second.ID},
+				archivedEventIDs(t, oldPath),
+			)
+		})
+	}
+}
+
+// TestRename_BeforeTheNameIsSaved covers the order the handlers
+// use: they rename before they save the new name, so a delivery in
+// between must write under the new name although the main database
+// still has the old one. It also shows that renaming an archive that
+// does not exist yet is not an error.
+func TestRename_BeforeTheNameIsSaved(t *testing.T) {
+	t.Parallel()
+
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
+
+	require.NoError(
+		t, env.eng.Rename(tgt.ID, "Orders", "Archive"),
+	)
+
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"n":1}`)
+	env.eng.ExportDeliverDatabase(
+		webhookDB, seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
+	)
+
+	assert.FileExists(
+		t,
+		filepath.Join(
+			env.dataDir, "archive-orders-archive-"+tgt.ID+".db",
+		),
+	)
+	assert.NoFileExists(t, env.archivePath(tgt))
+}
+
+// TestArchiveWriter_RenameMovesSidecars proves a rename carries
+// the -wal and -shm a crash can leave beside an archive no handle
+// has opened since. SQLite finds them by name, so a -wal left
+// behind would lose the transactions it holds.
+func TestArchiveWriter_RenameMovesSidecars(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	oldPath := filepath.Join(dir, "archive-old.db")
+	newPath := filepath.Join(dir, "archive-new.db")
+
+	for _, suffix := range archiveFileSuffixes() {
+		require.NoError(
+			t, os.WriteFile(oldPath+suffix, []byte(suffix), 0o600),
+		)
+	}
+
+	w := delivery.NewExportArchiveWriter(
+		oldPath, archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.Rename("archive-new.db"))
+
+	for _, suffix := range archiveFileSuffixes() {
+		assert.NoFileExists(t, oldPath+suffix)
+		assert.FileExists(t, newPath+suffix)
+	}
+
+	assert.Equal(t, newPath, w.Path())
+}
+
+// TestArchiveWriter_RenameMovesBackOnFailure makes the -wal fail to
+// move after the .db has moved, and proves the .db is moved back, so
+// the archive is never split across two names. The new name is 255
+// bytes, the longest a file name may be, so the .db can take it but
+// the -wal, four bytes longer, cannot.
+func TestArchiveWriter_RenameMovesBackOnFailure(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	oldPath := filepath.Join(dir, "archive-old.db")
+	newName := strings.Repeat("a", 252) + ".db"
+
+	for _, suffix := range archiveFileSuffixes() {
+		require.NoError(
+			t, os.WriteFile(oldPath+suffix, []byte(suffix), 0o600),
+		)
+	}
+
+	w := delivery.NewExportArchiveWriter(
+		oldPath, archiveTestLogger(), 0,
+	)
+
+	require.Error(t, w.Rename(newName))
+
+	for _, suffix := range archiveFileSuffixes() {
+		assert.FileExists(t, oldPath+suffix)
+	}
+
+	assert.NoFileExists(t, filepath.Join(dir, newName))
+	assert.Equal(t, oldPath, w.Path())
+}

internal/delivery/target_http.go

@@ -442,7 +442,9 @@ func (t *httpTarget) doHTTPRequest(
 		)
 	}
 
-	originScoped := applyRequestHeaders(req, event, cfg)
+	originScoped := applyRequestHeaders(
+		req, event, cfg, t.eng.userAgent(),
+	)
 
 	client := t.clientForRequest(cfg, originScoped)
 
@@ -562,10 +564,13 @@ func isForwardableHeader(name string) bool {
 // Content-Type goes out once: a Content-Type configured on the target
 // wins, otherwise the event's ContentType, otherwise none. The inbound
 // Content-Type in the event's headers is never forwarded.
+//
+// userAgent is set last, over any configured or inbound User-Agent.
 func applyRequestHeaders(
 	req *http.Request,
 	event *database.Event,
 	cfg *HTTPTargetConfig,
+	userAgent string,
 ) []string {
 	if event.ContentType != "" {
 		req.Header.Set(
@@ -580,7 +585,7 @@ func applyRequestHeaders(
 		originScoped[http.CanonicalHeaderKey(k)] = struct{}{}
 	}
 
-	req.Header.Set("User-Agent", "webhooker/1.0")
+	req.Header.Set("User-Agent", userAgent)
 
 	// A Content-Type configured on the target describes the body
 	// being sent rather than the sender. A 307/308 preserves the

internal/delivery/target_slack.go

@@ -136,7 +136,7 @@ func (t *slackTarget) attempt(
 	}
 
 	req.Header.Set("Content-Type", "application/json")
-	req.Header.Set("User-Agent", "webhooker/1.0")
+	req.Header.Set("User-Agent", t.eng.userAgent())
 
 	resp, doErr := executeHTTPRequest(t.client, req)
 	durationMs := time.Since(start).Milliseconds()

internal/delivery/user_agent_test.go

@@ -0,0 +1,91 @@
+package delivery_test
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"net/netip"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/fx/fxtest"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+	"sneak.berlin/go/webhooker/internal/globals"
+	"sneak.berlin/go/webhooker/internal/logger"
+	"sneak.berlin/go/webhooker/internal/metrics"
+)
+
+// Both the http and the slack target send webhooker/ and the version
+// in Globals, the value the web UI footer shows. A User-Agent
+// configured on the target or carried in by the sender does not
+// replace it.
+func TestUserAgent_IsTheBuildVersion(t *testing.T) {
+	t.Parallel()
+
+	const want = "webhooker/1.2.3-test"
+
+	userAgents := make(chan string, 1)
+
+	ts := httptest.NewServer(http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			userAgents <- r.Header.Get("User-Agent")
+
+			w.WriteHeader(http.StatusOK)
+		},
+	))
+	defer ts.Close()
+
+	g := &globals.Globals{Version: "1.2.3-test"}
+	lc := fxtest.NewLifecycle(t)
+
+	log, err := logger.New(lc, logger.LoggerParams{Globals: g})
+	require.NoError(t, err)
+
+	e := delivery.New(lc, delivery.EngineParams{
+		Globals: g,
+		Logger:  log,
+		// httptest listens on loopback, which the default guard
+		// refuses.
+		SSRFGuard: delivery.NewTestGuard(
+			netip.MustParsePrefix("127.0.0.0/8"),
+		),
+		Metrics: metrics.New(prometheus.NewRegistry()),
+	})
+
+	statusCode, _, _, err := e.ExportDoHTTPRequest(
+		context.Background(),
+		&delivery.HTTPTargetConfig{
+			URL:     ts.URL,
+			Headers: map[string]string{"User-Agent": "configured/1"},
+		},
+		&database.Event{Headers: `{"User-Agent":["curl/8"]}`},
+	)
+	require.NoError(t, err)
+	require.Equal(t, http.StatusOK, statusCode)
+	require.Len(t, userAgents, 1, "the http target sent no request")
+	assert.Equal(t, want, <-userAgents, "http target")
+
+	db := testWebhookDB(t)
+	targetID := uuid.New().String()
+
+	slackCfg, err := json.Marshal(
+		delivery.SlackTargetConfig{WebhookURL: ts.URL},
+	)
+	require.NoError(t, err)
+
+	event := seedEvent(t, db, `{"action":"test"}`)
+	dlv := seedDelivery(
+		t, db, event.ID, targetID, database.DeliveryStatusPending,
+	)
+
+	e.ExportDeliverSlack(context.Background(), db, buildSlackDelivery(
+		dlv, event, targetID, "test-slack", string(slackCfg),
+	))
+	require.Len(t, userAgents, 1, "the slack target sent no request")
+	assert.Equal(t, want, <-userAgents, "slack target")
+}

internal/handlers/auth.go

@@ -74,7 +74,7 @@ func (h *Handlers) HandleLoginSubmit() http.HandlerFunc {
 		err := r.ParseForm()
 		if err != nil {
 			h.log.Error("failed to parse form", "error", err)
-			http.Error(w, "Bad request", http.StatusBadRequest)
+			h.renderError(w, r, http.StatusBadRequest)
 
 			return
 		}
@@ -212,11 +212,7 @@ func (h *Handlers) authenticateUser(
 
 	valid, err := database.VerifyPassword(password, user.Password)
 	if err != nil {
-		h.log.Error("failed to verify password", "error", err)
-		http.Error(
-			w, "Internal server error",
-			http.StatusInternalServerError,
-		)
+		h.serverError(w, r, "failed to verify password", err)
 
 		return user, err
 	}
@@ -288,24 +284,14 @@ func (h *Handlers) createAuthenticatedSession(
 ) error {
 	oldSess, err := h.session.Get(r)
 	if err != nil {
-		h.log.Error("failed to get session", "error", err)
-		http.Error(
-			w, "Internal server error",
-			http.StatusInternalServerError,
-		)
+		h.serverError(w, r, "failed to get session", err)
 
 		return err
 	}
 
 	sess, err := h.session.Regenerate(r, w, oldSess)
 	if err != nil {
-		h.log.Error(
-			"failed to regenerate session", "error", err,
-		)
-		http.Error(
-			w, "Internal server error",
-			http.StatusInternalServerError,
-		)
+		h.serverError(w, r, "failed to regenerate session", err)
 
 		return err
 	}
@@ -314,11 +300,7 @@ func (h *Handlers) createAuthenticatedSession(
 
 	err = h.session.Save(r, w, sess)
 	if err != nil {
-		h.log.Error("failed to save session", "error", err)
-		http.Error(
-			w, "Internal server error",
-			http.StatusInternalServerError,
-		)
+		h.serverError(w, r, "failed to save session", err)
 
 		return err
 	}
@@ -351,7 +333,9 @@ func (h *Handlers) HandleLogout() http.HandlerFunc {
 			)
 		}
 
-		// Redirect to login page
-		http.Redirect(w, r, "/pages/login", http.StatusSeeOther)
+		http.Redirect(
+			w, r, withNotice("/pages/login", signedOut),
+			http.StatusSeeOther,
+		)
 	}
 }

internal/handlers/delivery_replay.go

@@ -11,72 +11,37 @@ import (
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
-// replayOutcomeParam is the query parameter the replay POST redirects
-// with and the event log page reads its banner from.
-const replayOutcomeParam = "replay"
-
-// replayOutcomeCode is the outcome of a replay POST. The redirect
-// carries one of these fixed codes rather than a message, so nothing a
-// client submits can reach the rendered page through it.
-type replayOutcomeCode string
-
+// The outcomes of a replay POST, as the notice codes its redirect
+// carries. noticeFor holds the line each one shows.
 const (
 	// replayQueued reports that a new delivery was created and handed
 	// to the delivery engine.
-	replayQueued replayOutcomeCode = "queued"
+	replayQueued noticeCode = "replay-queued"
 
 	// replayTargetDeleted reports a target that once existed and has
 	// since been deleted. Deletes are soft and deliveries carry no
 	// foreign key to the target row, so the history survives its
 	// target and this is the ordinary case for an old event.
-	replayTargetDeleted replayOutcomeCode = "target-deleted"
+	replayTargetDeleted noticeCode = "replay-target-deleted"
 
 	// replayTargetMissing reports a target id that names no row at
 	// all, deleted or otherwise.
-	replayTargetMissing replayOutcomeCode = "target-missing"
+	replayTargetMissing noticeCode = "replay-target-missing"
 
 	// replayTargetInactive reports a target the operator has
 	// deactivated. A deactivated target receives no new deliveries, so
 	// a replay to it would be a delivery they switched off.
-	replayTargetInactive replayOutcomeCode = "target-inactive"
+	replayTargetInactive noticeCode = "replay-target-inactive"
 
 	// replayNotTerminal reports a delivery the engine has not finished
 	// with.
-	replayNotTerminal replayOutcomeCode = "not-terminal"
+	replayNotTerminal noticeCode = "replay-not-terminal"
 
 	// replayInFlight reports that an earlier replay of this event to
 	// this target is still running.
-	replayInFlight replayOutcomeCode = "in-flight"
+	replayInFlight noticeCode = "replay-in-flight"
 )
 
-// replayOutcome returns the banner the event log page shows for an
-// outcome code, and whether the replay was queued. An unrecognised
-// code yields no banner.
-func replayOutcome(code string) (string, bool) {
-	switch replayOutcomeCode(code) {
-	case replayQueued:
-		return "Replay queued: a new delivery was created against " +
-			"the target's current configuration.", true
-	case replayTargetDeleted:
-		return "Not replayed: the target this delivery was for has " +
-			"been deleted. Recreate the target, then replay.", false
-	case replayTargetMissing:
-		return "Not replayed: the target this delivery was for no " +
-			"longer exists.", false
-	case replayTargetInactive:
-		return "Not replayed: the target this delivery was for is " +
-			"deactivated. Activate it, then replay.", false
-	case replayNotTerminal:
-		return "Not replayed: this delivery has not finished yet.",
-			false
-	case replayInFlight:
-		return "Not replayed: a delivery of this event to this " +
-			"target is already in flight.", false
-	default:
-		return "", false
-	}
-}
-
 // HandleDeliveryReplay re-sends a finished delivery's event to its
 // target.
 //
@@ -105,9 +70,7 @@ func (h *Handlers) HandleDeliveryReplay() http.HandlerFunc {
 		// middleware, which runs before CSRF parses the form.
 		err := r.ParseForm()
 		if err != nil {
-			http.Error(
-				w, "Bad request", http.StatusBadRequest,
-			)
+			h.renderError(w, r, http.StatusBadRequest)
 
 			return
 		}
@@ -124,14 +87,14 @@ func (h *Handlers) replayDelivery(
 	webhook database.Webhook,
 ) {
 	if !h.dbMgr.DBExists(webhook.ID) {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return
 	}
 
 	webhookDB, err := h.dbMgr.GetDB(webhook.ID)
 	if err != nil {
-		h.serverError(w, "failed to get webhook database", err)
+		h.serverError(w, r, "failed to get webhook database", err)
 
 		return
 	}
@@ -142,14 +105,14 @@ func (h *Handlers) replayDelivery(
 	}
 
 	if !original.Status.Terminal() {
-		h.finishReplay(w, r, webhook, replayNotTerminal)
+		redirectToEventLog(w, r, webhook, replayNotTerminal)
 
 		return
 	}
 
 	target, code := h.replayTarget(webhook.ID, original.TargetID)
 	if target == nil {
-		h.finishReplay(w, r, webhook, code)
+		redirectToEventLog(w, r, webhook, code)
 
 		return
 	}
@@ -173,7 +136,7 @@ func (h *Handlers) loadReplaySource(
 			&original, "id = ?", chi.URLParam(r, "deliveryID"),
 		).Error
 	if err != nil {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return nil, false
 	}
@@ -195,14 +158,14 @@ func (h *Handlers) queueReplay(
 	)
 	if err != nil {
 		h.serverError(
-			w, "failed to count in-flight deliveries", err,
+			w, r, "failed to count in-flight deliveries", err,
 		)
 
 		return
 	}
 
 	if inFlight > 0 {
-		h.finishReplay(w, r, webhook, replayInFlight)
+		redirectToEventLog(w, r, webhook, replayInFlight)
 
 		return
 	}
@@ -212,7 +175,7 @@ func (h *Handlers) queueReplay(
 	err = webhookDB.
 		First(&event, "id = ?", original.EventID).Error
 	if err != nil {
-		h.serverError(w, "failed to load event for replay", err)
+		h.serverError(w, r, "failed to load event for replay", err)
 
 		return
 	}
@@ -222,7 +185,7 @@ func (h *Handlers) queueReplay(
 	)
 	if err != nil {
 		h.serverError(
-			w, "failed to create replay delivery", err,
+			w, r, "failed to create replay delivery", err,
 		)
 
 		return
@@ -240,7 +203,7 @@ func (h *Handlers) queueReplay(
 		"delivery_id", task.DeliveryID,
 	)
 
-	h.finishReplay(w, r, webhook, replayQueued)
+	redirectToEventLog(w, r, webhook, replayQueued)
 }
 
 // replayTarget loads the delivery's target as it stands now.
@@ -253,7 +216,7 @@ func (h *Handlers) queueReplay(
 // with the returned code saying why.
 func (h *Handlers) replayTarget(
 	webhookID, targetID string,
-) (*database.Target, replayOutcomeCode) {
+) (*database.Target, noticeCode) {
 	var target database.Target
 
 	err := h.db.DB().Unscoped().Where(
@@ -363,17 +326,16 @@ func replayBody(body string) *string {
 	return &body
 }
 
-// finishReplay redirects back to the event log the replay was
-// triggered from, carrying the outcome code the page turns into a
-// banner and the page number the form submitted.
-func (h *Handlers) finishReplay(
+// redirectToEventLog redirects a replay or resubmit back to the event
+// log it was triggered from, carrying the outcome as its notice and
+// the page number the form submitted.
+func redirectToEventLog(
 	w http.ResponseWriter,
 	r *http.Request,
 	webhook database.Webhook,
-	code replayOutcomeCode,
+	code noticeCode,
 ) {
-	dest := "/hook/" + webhook.ID + "/events?" +
-		replayOutcomeParam + "=" + string(code)
+	dest := withNotice("/hook/"+webhook.ID+"/events", code)
 
 	// The page is read from the form rather than the query string:
 	// this is a POST, and its query string is what logs and Referer

internal/handlers/delivery_replay_test.go

@@ -212,7 +212,7 @@ func TestHandleDeliveryReplay_AppendsDeliveryAndLeavesOriginal(
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=queued",
+		"/hook/"+wh.ID+"/events?notice=replay-queued",
 		w.Header().Get("Location"),
 	)
 
@@ -362,7 +362,7 @@ func TestHandleDeliveryReplay_RefusesDeletedTarget(t *testing.T) {
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=target-deleted",
+		"/hook/"+wh.ID+"/events?notice=replay-target-deleted",
 		w.Header().Get("Location"),
 	)
 
@@ -390,7 +390,7 @@ func TestHandleDeliveryReplay_RefusesDeletedTarget(t *testing.T) {
 	require.Equal(t, http.StatusSeeOther, missing.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=target-missing",
+		"/hook/"+wh.ID+"/events?notice=replay-target-missing",
 		missing.Header().Get("Location"),
 	)
 }
@@ -431,7 +431,7 @@ func TestHandleDeliveryReplay_RefusesWhileEarlierReplayInFlight(
 	require.Equal(t, http.StatusSeeOther, first.Code)
 	require.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=queued",
+		"/hook/"+wh.ID+"/events?notice=replay-queued",
 		first.Header().Get("Location"),
 	)
 
@@ -439,7 +439,7 @@ func TestHandleDeliveryReplay_RefusesWhileEarlierReplayInFlight(
 	require.Equal(t, http.StatusSeeOther, second.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=in-flight",
+		"/hook/"+wh.ID+"/events?notice=replay-in-flight",
 		second.Header().Get("Location"),
 	)
 
@@ -465,7 +465,7 @@ func TestHandleDeliveryReplay_RefusesWhileEarlierReplayInFlight(
 	require.Equal(t, http.StatusSeeOther, pending.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=not-terminal",
+		"/hook/"+wh.ID+"/events?notice=replay-not-terminal",
 		pending.Header().Get("Location"),
 	)
 }
@@ -509,7 +509,7 @@ func TestHandleSourceLogs_RendersReplayControlAndBanner(t *testing.T) {
 	assert.Contains(t, body, ">Replay<")
 
 	refused := renderSourceLogsPageWithQuery(
-		t, h, sess, wh.ID, "?replay=target-deleted",
+		t, h, sess, wh.ID, "?notice=replay-target-deleted",
 	)
 
 	assert.Contains(t, refused, "alert-error")
@@ -517,7 +517,7 @@ func TestHandleSourceLogs_RendersReplayControlAndBanner(t *testing.T) {
 
 	// An outcome code nobody issued renders no banner at all.
 	unknown := renderSourceLogsPageWithQuery(
-		t, h, sess, wh.ID, "?replay=made-up",
+		t, h, sess, wh.ID, "?notice=made-up",
 	)
 
 	assert.NotContains(t, unknown, "alert-error")

internal/handlers/error_page_test.go

@@ -0,0 +1,53 @@
+package handlers_test
+
+import (
+	"context"
+	"html/template"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"sneak.berlin/go/webhooker/internal/handlers"
+)
+
+// TestErrorPage_RenderFailureKeepsStatus proves that an error page
+// which cannot render answers with the status it was reporting, as
+// plain text, and is not attempted again: a page whose own render
+// fails reaches the error page, and the error page failing as well
+// ends there with the 500.
+func TestErrorPage_RenderFailureKeepsStatus(t *testing.T) {
+	t.Parallel()
+
+	var h *handlers.Handlers
+
+	app := newTestApp(t, &h)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	// .Status is an int, so asking it for a field fails the render.
+	failing := `{{.Status.Missing}}`
+	h.AddTemplateForTest("error.html", template.Must(
+		template.New("error").Parse(failing),
+	))
+	h.AddTemplateForTest("failing.html", template.Must(
+		template.New("failing").Parse(`{{.Data.Missing}}`),
+	))
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/", nil,
+	)
+
+	w := httptest.NewRecorder()
+	h.HandleErrorPage(http.StatusNotFound).ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusNotFound, w.Code)
+	assert.Equal(t, "Not Found\n", w.Body.String())
+
+	w = httptest.NewRecorder()
+	h.RenderTemplateForTest(w, req, "failing.html", 0)
+
+	assert.Equal(t, http.StatusInternalServerError, w.Code)
+	assert.Equal(t, "Internal Server Error\n", w.Body.String())
+}

internal/handlers/event_body.go

@@ -52,7 +52,7 @@ func (h *Handlers) HandleEventBodyDownload() http.HandlerFunc {
 		// steered by a client.
 		eventID, err := uuid.Parse(chi.URLParam(r, "eventID"))
 		if err != nil {
-			http.NotFound(w, r)
+			h.renderError(w, r, http.StatusNotFound)
 
 			return
 		}
@@ -103,21 +103,21 @@ func (h *Handlers) serveEventBody(
 	eventID string,
 ) {
 	if !h.dbMgr.DBExists(webhook.ID) {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return
 	}
 
 	webhookDB, err := h.dbMgr.GetDB(webhook.ID)
 	if err != nil {
-		h.serverError(w, "failed to get webhook database", err)
+		h.serverError(w, r, "failed to get webhook database", err)
 
 		return
 	}
 
 	body, found, err := eventBody(webhookDB, webhook.ID, eventID)
 	if err != nil {
-		h.serverError(w, "failed to read event body", err)
+		h.serverError(w, r, "failed to read event body", err)
 
 		return
 	}
@@ -130,7 +130,7 @@ func (h *Handlers) serveEventBody(
 	// row and the whole body is served, or it does not and the
 	// response is a clean 404.
 	if !found {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return
 	}

internal/handlers/event_resubmit.go

@@ -3,7 +3,6 @@ package handlers
 import (
 	"errors"
 	"net/http"
-	"strconv"
 
 	"github.com/go-chi/chi"
 	"github.com/google/uuid"
@@ -11,43 +10,19 @@ import (
 	"sneak.berlin/go/webhooker/internal/database"
 )
 
-// resubmitOutcomeParam is the query parameter the resubmit POST
-// redirects with and the event log page reads its banner from.
-const resubmitOutcomeParam = "resubmit"
-
-// resubmitOutcomeCode is the outcome of a resubmit POST. The redirect
-// carries one of these fixed codes rather than a message, so nothing a
-// client submits can reach the rendered page through it.
-type resubmitOutcomeCode string
-
+// The outcomes of a resubmit POST, as the notice codes its redirect
+// carries. noticeFor holds the line each one shows.
 const (
 	// resubmitQueued reports that a new event was stored and its
 	// deliveries handed to the delivery engine.
-	resubmitQueued resubmitOutcomeCode = "queued"
+	resubmitQueued noticeCode = "resubmit-queued"
 
 	// resubmitNoTargets reports a source with no active targets. The
 	// new event is stored either way, exactly as a received event
 	// with no targets is.
-	resubmitNoTargets resubmitOutcomeCode = "no-targets"
+	resubmitNoTargets noticeCode = "resubmit-no-targets"
 )
 
-// resubmitOutcome returns the banner the event log page shows for an
-// outcome code, and whether the resubmit was queued. An unrecognised
-// code yields no banner.
-func resubmitOutcome(code string) (string, bool) {
-	switch resubmitOutcomeCode(code) {
-	case resubmitQueued:
-		return "Resubmitted: a new event was created from the stored " +
-			"one and queued to every active target.", true
-	case resubmitNoTargets:
-		return "Resubmitted: a new event was created, but this " +
-				"source has no active targets, so nothing was queued.",
-			true
-	default:
-		return "", false
-	}
-}
-
 // resubmitSource is the stored event a resubmit copies. Its body is
 // read as bytes rather than as a string so the copy is byte-identical
 // to what was received, whatever the payload's encoding.
@@ -99,7 +74,7 @@ func (h *Handlers) HandleEventResubmit() http.HandlerFunc {
 		// middleware, which runs before CSRF parses the form.
 		err := r.ParseForm()
 		if err != nil {
-			http.Error(w, "Bad request", http.StatusBadRequest)
+			h.renderError(w, r, http.StatusBadRequest)
 
 			return
 		}
@@ -120,20 +95,20 @@ func (h *Handlers) resubmitEvent(
 	// alphabet rather than from the request.
 	eventID, err := uuid.Parse(chi.URLParam(r, "eventID"))
 	if err != nil {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return
 	}
 
 	if !h.dbMgr.DBExists(webhook.ID) {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return
 	}
 
 	webhookDB, err := h.dbMgr.GetDB(webhook.ID)
 	if err != nil {
-		h.serverError(w, "failed to get webhook database", err)
+		h.serverError(w, r, "failed to get webhook database", err)
 
 		return
 	}
@@ -147,7 +122,7 @@ func (h *Handlers) resubmitEvent(
 		webhookDB, webhook.ID, eventID.String(),
 	)
 	if err != nil {
-		h.serverError(w, "failed to load event to resubmit", err)
+		h.serverError(w, r, "failed to load event to resubmit", err)
 
 		return
 	}
@@ -155,7 +130,7 @@ func (h *Handlers) resubmitEvent(
 	// A miss is a 404 whether the event was reaped, belongs to
 	// another webhook, or never existed.
 	if !found {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return
 	}
@@ -207,7 +182,7 @@ func (h *Handlers) queueResubmit(
 	// inactive one is skipped rather than refused.
 	targets, err := h.loadActiveTargets(webhook.ID)
 	if err != nil {
-		h.serverError(w, "failed to query targets", err)
+		h.serverError(w, r, "failed to query targets", err)
 
 		return
 	}
@@ -225,7 +200,7 @@ func (h *Handlers) queueResubmit(
 		targets,
 	)
 	if err != nil {
-		h.serverError(w, "failed to store resubmitted event", err)
+		h.serverError(w, r, "failed to store resubmitted event", err)
 
 		return
 	}
@@ -245,29 +220,5 @@ func (h *Handlers) queueResubmit(
 		code = resubmitNoTargets
 	}
 
-	h.finishResubmit(w, r, webhook, code)
-}
-
-// finishResubmit redirects back to the event log the resubmit was
-// triggered from, carrying the outcome code the page turns into a
-// banner and the page number the form submitted.
-func (h *Handlers) finishResubmit(
-	w http.ResponseWriter,
-	r *http.Request,
-	webhook database.Webhook,
-	code resubmitOutcomeCode,
-) {
-	dest := "/hook/" + webhook.ID + "/events?" +
-		resubmitOutcomeParam + "=" + string(code)
-
-	// The page is read from the form rather than the query string:
-	// this is a POST, and its query string is what logs and Referer
-	// headers record.
-	if page := pageOrFirst(
-		r.PostFormValue("page"),
-	); page > 1 {
-		dest += "&page=" + strconv.Itoa(page)
-	}
-
-	http.Redirect(w, r, dest, http.StatusSeeOther)
+	redirectToEventLog(w, r, webhook, code)
 }

internal/handlers/event_resubmit_test.go

@@ -154,7 +154,7 @@ func TestHandleEventResubmit_DeliversToTargetCreatedAfterTheEvent(
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?resubmit=queued",
+		"/hook/"+wh.ID+"/events?notice=resubmit-queued",
 		w.Header().Get("Location"),
 	)
 
@@ -282,7 +282,7 @@ func TestHandleEventResubmit_IsRepeatable(t *testing.T) {
 		require.Equal(t, http.StatusSeeOther, w.Code)
 		assert.Equal(
 			t,
-			"/hook/"+wh.ID+"/events?resubmit=queued",
+			"/hook/"+wh.ID+"/events?notice=resubmit-queued",
 			w.Header().Get("Location"),
 			"a resubmit must not be refused while an earlier "+
 				"one is in flight",
@@ -436,7 +436,7 @@ func TestHandleEventResubmit_SkipsInactiveTarget(t *testing.T) {
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?resubmit=queued",
+		"/hook/"+wh.ID+"/events?notice=resubmit-queued",
 		w.Header().Get("Location"),
 		"an inactive target is skipped, not an error",
 	)
@@ -482,7 +482,7 @@ func TestHandleEventResubmit_NoActiveTargetsStillStoresEvent(
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?resubmit=no-targets",
+		"/hook/"+wh.ID+"/events?notice=resubmit-no-targets",
 		w.Header().Get("Location"),
 	)
 

internal/handlers/export_test.go

@@ -1,9 +1,11 @@
 package handlers
 
 import (
+	"context"
 	"html/template"
 	"log/slog"
 	"net/http"
+	"net/http/httptest"
 	"time"
 
 	"gorm.io/gorm"
@@ -65,7 +67,7 @@ func (s *Handlers) LoadEventLogViewsForTest(
 	page int,
 ) []EventLogView {
 	views, _, _ := s.loadEventsWithDeliveries(
-		w, webhook, nil, page,
+		w, newRequestForTest(), webhook, nil, page,
 	)
 
 	return views
@@ -94,6 +96,14 @@ func FinishedByTargetForTest(
 	return finishedByTarget(webhookDB, since)
 }
 
+// newRequestForTest is the request the helpers here pass on for
+// callers that have none: it is used only to render the error page.
+func newRequestForTest() *http.Request {
+	return httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/", nil,
+	)
+}
+
 // AddTemplateForTest registers a template under a page name so that
 // the handlers_test package can drive the render path with a
 // template of its own.
@@ -147,5 +157,5 @@ func (s *Handlers) BuildDatabaseTargetConfigForTest(
 	w http.ResponseWriter,
 	expiry string,
 ) (string, error) {
-	return s.buildDatabaseTargetConfig(w, expiry)
+	return s.buildDatabaseTargetConfig(w, newRequestForTest(), expiry)
 }

internal/handlers/handlers.go

@@ -12,6 +12,7 @@ import (
 	"net/http"
 	"sync/atomic"
 
+	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/fx"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
@@ -62,8 +63,10 @@ type HandlersParams struct {
 	Session      *session.Session
 	Middleware   *middleware.Middleware
 	Notifier     delivery.Notifier
-	Evictor      delivery.WebhookEvictor
+	Archives     delivery.Archives
 	SSRFGuard    *delivery.Guard
+	Metrics      *metrics.Set
+	Registry     *prometheus.Registry
 }
 
 // Handlers provides HTTP handler methods for all application
@@ -77,7 +80,7 @@ type Handlers struct {
 	session   *session.Session
 	mw        *middleware.Middleware
 	notifier  delivery.Notifier
-	evictor   delivery.WebhookEvictor
+	archives  delivery.Archives
 	mtr       *metrics.Set
 	templates map[string]*template.Template
 
@@ -94,10 +97,10 @@ type Handlers struct {
 
 // parsePageTemplate parses a page-specific template set from the
 // embedded FS. Each page template is combined with the shared
-// base, htmlheader, and navbar templates, and with any further files
-// the page includes. The page file must be listed first so that its
-// root action ({{template "base" .}}) becomes the template set's entry
-// point.
+// base, htmlheader, navbar and notice templates, and with any further
+// files the page includes. The page file must be listed first so that
+// its root action ({{template "base" .}}) becomes the template set's
+// entry point.
 func parsePageTemplate(
 	pageFile string, included ...string,
 ) *template.Template {
@@ -106,6 +109,7 @@ func parsePageTemplate(
 		"base.html",
 		"htmlheader.html",
 		"navbar.html",
+		"notice.html",
 	}, included...)
 
 	return template.Must(
@@ -128,8 +132,8 @@ func New(
 	s.session = params.Session
 	s.mw = params.Middleware
 	s.notifier = params.Notifier
-	s.evictor = params.Evictor
-	s.mtr = metrics.Default()
+	s.archives = params.Archives
+	s.mtr = params.Metrics
 	s.ssrf = params.SSRFGuard
 
 	// Parse all page templates once at startup
@@ -142,6 +146,7 @@ func New(
 		"source_edit.html":   parsePageTemplate("source_edit.html"),
 		"source_logs.html":   parsePageTemplate("source_logs.html"),
 		"target_edit.html":   parsePageTemplate("target_edit.html"),
+		"error.html":         parsePageTemplate("error.html"),
 	}
 
 	lc.Append(fx.Hook{
@@ -153,6 +158,16 @@ func New(
 	return s, nil
 }
 
+// HandleErrorPage returns a handler that answers every request with
+// the error page for status. The router uses it for unknown paths, the
+// CSRF middleware for a refused form, and each admin page route
+// group's recoverer for a panic.
+func (s *Handlers) HandleErrorPage(status int) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		s.renderError(w, r, status)
+	}
+}
+
 func (s *Handlers) respondJSON(
 	w http.ResponseWriter,
 	_ *http.Request,
@@ -170,15 +185,78 @@ func (s *Handlers) respondJSON(
 	}
 }
 
-// serverError logs an error and sends a 500 response.
+// serverError logs an error and answers with the 500 error page.
 func (s *Handlers) serverError(
-	w http.ResponseWriter, msg string, err error,
+	w http.ResponseWriter, r *http.Request, msg string, err error,
 ) {
 	s.log.Error(msg, "error", err)
-	http.Error(
-		w, "Internal server error",
-		http.StatusInternalServerError,
-	)
+	s.renderError(w, r, http.StatusInternalServerError)
+}
+
+// renderError answers with status and the error page: the normal
+// layout, one fixed line explaining the status, and a link back to the
+// webhook list, or to sign-in when nobody is signed in.
+//
+// It renders the page itself rather than through renderTemplate,
+// whose own failure comes here. If the error page cannot render
+// either, the answer is the same status in plain text: never a second
+// attempt, and never a different status.
+func (s *Handlers) renderError(
+	w http.ResponseWriter,
+	r *http.Request,
+	status int,
+) {
+	// The page names the signed-in user, and some error pages are
+	// served outside the routes where NoCache runs.
+	w.Header().Set("Cache-Control", "no-store")
+
+	// No notice: one would say an action worked above a page saying
+	// the request failed.
+	data := s.pageData(r, map[string]any{
+		"Status":     status,
+		"StatusText": http.StatusText(status),
+		"Message":    errorPageText(status),
+	}, nil)
+
+	var buf bytes.Buffer
+
+	err := s.templates["error.html"].Execute(&buf, data)
+	if err != nil {
+		s.log.Error("failed to render error page", "error", err)
+		http.Error(w, http.StatusText(status), status)
+
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	w.WriteHeader(status)
+
+	_, err = buf.WriteTo(w)
+	if err != nil {
+		s.log.Error("failed to write error page", "error", err)
+	}
+}
+
+// errorPageText is the line the error page shows for status. It is
+// fixed per status, so the page tells the reader no more than the
+// plain-text answers it replaced did.
+func errorPageText(status int) string {
+	switch status {
+	case http.StatusBadRequest:
+		return "The request could not be read."
+	case http.StatusForbidden:
+		return "The request was refused. If it came from a form " +
+			"left open for a long time, reload the page and try " +
+			"again."
+	case http.StatusNotFound:
+		return "There is nothing here. It may have been deleted, " +
+			"or the address may be wrong."
+	case http.StatusServiceUnavailable:
+		return "The server is busy. Please try again in a moment."
+	default: // http.StatusInternalServerError
+		return "Something went wrong on the server. Please try " +
+			"again."
+	}
 }
 
 // UserInfo represents user information for templates
@@ -192,6 +270,7 @@ type templateDataWrapper struct {
 	User      *UserInfo
 	CSRFToken string
 	Version   string
+	Notice    *notice
 	Data      any
 }
 
@@ -231,14 +310,20 @@ func (s *Handlers) renderTemplate(
 			"template not found",
 			"template", pageTemplate,
 		)
-		http.Error(
-			w, "Internal server error",
-			http.StatusInternalServerError,
-		)
+		s.renderError(w, r, http.StatusInternalServerError)
 
 		return
 	}
 
+	s.executeTemplate(w, r, tmpl, s.pageData(r, data, noticeFor(r)))
+}
+
+// pageData adds the fields the shared layout renders to a page's own
+// data. The layout shows the notice, when there is one, above the
+// page.
+func (s *Handlers) pageData(
+	r *http.Request, data any, pageNotice *notice,
+) any {
 	userInfo := s.getUserInfo(r)
 	csrfToken := middleware.CSRFToken(r)
 
@@ -252,19 +337,18 @@ func (s *Handlers) renderTemplate(
 		m["User"] = userInfo
 		m["CSRFToken"] = csrfToken
 		m["Version"] = version
-		s.executeTemplate(w, tmpl, m)
+		m["Notice"] = pageNotice
 
-		return
+		return m
 	}
 
-	wrapper := templateDataWrapper{
+	return templateDataWrapper{
 		User:      userInfo,
 		CSRFToken: csrfToken,
 		Version:   version,
+		Notice:    pageNotice,
 		Data:      data,
 	}
-
-	s.executeTemplate(w, tmpl, wrapper)
 }
 
 // executeTemplate renders the template into a buffer and writes to
@@ -277,6 +361,7 @@ func (s *Handlers) renderTemplate(
 // this reason.
 func (s *Handlers) executeTemplate(
 	w http.ResponseWriter,
+	r *http.Request,
 	tmpl *template.Template,
 	data any,
 ) {
@@ -287,10 +372,7 @@ func (s *Handlers) executeTemplate(
 		s.log.Error(
 			"failed to execute template", "error", err,
 		)
-		http.Error(
-			w, "Internal server error",
-			http.StatusInternalServerError,
-		)
+		s.renderError(w, r, http.StatusInternalServerError)
 
 		return
 	}

internal/handlers/handlers_test.go

@@ -3,6 +3,7 @@ package handlers_test
 import (
 	"context"
 	"errors"
+	"fmt"
 	"html/template"
 	"net/http"
 	"net/http/httptest"
@@ -20,6 +21,7 @@ import (
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/healthcheck"
 	"sneak.berlin/go/webhooker/internal/logger"
+	"sneak.berlin/go/webhooker/internal/metrics"
 	"sneak.berlin/go/webhooker/internal/middleware"
 	"sneak.berlin/go/webhooker/internal/session"
 )
@@ -51,23 +53,77 @@ func (n *recordingNotifier) Tasks() []delivery.Task {
 	return out
 }
 
-// recordingEvictor is a delivery.WebhookEvictor that records
-// the webhook ids it was asked to evict, so a test can prove
-// that a deletion path reached the delivery engine.
-type recordingEvictor struct {
-	mu      sync.Mutex
-	evicted []string
+// recordingArchives is a delivery.Archives that records what it
+// was asked to do, so a test can prove that a deletion or rename
+// path reached the delivery engine. After FailRenames, every
+// rename of that target fails with the given error.
+type recordingArchives struct {
+	mu             sync.Mutex
+	evicted        []string
+	evictedTargets []string
+	renames        []archiveRename
+	renameErrs     map[string]error
 }
 
-func (r *recordingEvictor) EvictWebhook(webhookID string) {
+// errInjectedRename is the failure a test hands FailRenames.
+var errInjectedRename = errors.New("injected rename failure")
+
+// errNameTaken is what the delivery engine returns when a file
+// already has an archive's new name, here archive-taken.db.
+var errNameTaken = fmt.Errorf(
+	"%w: archive-taken.db", delivery.ErrArchiveNameTaken,
+)
+
+// archiveRename is one recorded Rename call.
+type archiveRename struct {
+	TargetID    string
+	WebhookName string
+	TargetName  string
+}
+
+func (r *recordingArchives) EvictWebhook(webhookID string) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
 	r.evicted = append(r.evicted, webhookID)
 }
 
+func (r *recordingArchives) EvictTarget(targetID string) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	r.evictedTargets = append(r.evictedTargets, targetID)
+}
+
+func (r *recordingArchives) Rename(
+	targetID, webhookName, targetName string,
+) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	r.renames = append(r.renames, archiveRename{
+		TargetID:    targetID,
+		WebhookName: webhookName,
+		TargetName:  targetName,
+	})
+
+	return r.renameErrs[targetID]
+}
+
+// FailRenames makes every later rename of targetID fail with err.
+func (r *recordingArchives) FailRenames(targetID string, err error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if r.renameErrs == nil {
+		r.renameErrs = map[string]error{}
+	}
+
+	r.renameErrs[targetID] = err
+}
+
 // Evicted returns a copy of the recorded webhook ids.
-func (r *recordingEvictor) Evicted() []string {
+func (r *recordingArchives) Evicted() []string {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
@@ -77,6 +133,28 @@ func (r *recordingEvictor) Evicted() []string {
 	return out
 }
 
+// EvictedTargets returns a copy of the recorded target ids.
+func (r *recordingArchives) EvictedTargets() []string {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	out := make([]string, len(r.evictedTargets))
+	copy(out, r.evictedTargets)
+
+	return out
+}
+
+// Renames returns a copy of the recorded renames.
+func (r *recordingArchives) Renames() []archiveRename {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	out := make([]archiveRename, len(r.renames))
+	copy(out, r.renames)
+
+	return out
+}
+
 func newTestApp(
 	t *testing.T,
 	targets ...any,
@@ -103,12 +181,14 @@ func newTestApp(
 			func(n *recordingNotifier) delivery.Notifier {
 				return n
 			},
-			func() *recordingEvictor {
-				return &recordingEvictor{}
+			func() *recordingArchives {
+				return &recordingArchives{}
 			},
-			func(r *recordingEvictor) delivery.WebhookEvictor {
+			func(r *recordingArchives) delivery.Archives {
 				return r
 			},
+			metrics.NewRegistry,
+			metrics.New,
 			middleware.New,
 			delivery.NewGuard,
 			handlers.New,
@@ -307,10 +387,14 @@ func TestRenderTemplateMidRenderErrorSendsNoPartialBody(t *testing.T) {
 		t, http.StatusInternalServerError, w.Code,
 		"a failed render must report a 500",
 	)
-	assert.Equal(
-		t, "Internal server error\n", w.Body.String(),
+	assert.NotContains(
+		t, w.Body.String(), partialPageMarker,
 		"the response must carry no part of the aborted page",
 	)
+	assert.Contains(
+		t, w.Body.String(), "500 Internal Server Error",
+		"a failed render must answer with the error page",
+	)
 }
 
 func TestBuildDatabaseTargetConfig_Valid(t *testing.T) {

internal/handlers/metrics.go

@@ -0,0 +1,21 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+// HandleMetrics returns the Prometheus scrape handler for the
+// registry built by metrics.NewRegistry, which the HTTP, delivery, Go
+// runtime and process collectors register on. It is what
+// promhttp.Handler builds for the global default registry, including
+// the promhttp_metric_handler_* series that count scrapes, pointed at
+// that registry instead.
+func (s *Handlers) HandleMetrics() http.HandlerFunc {
+	reg := s.params.Registry
+
+	return promhttp.InstrumentMetricHandler(
+		reg, promhttp.HandlerFor(reg, promhttp.HandlerOpts{}),
+	).ServeHTTP
+}

internal/handlers/notice.go

@@ -0,0 +1,109 @@
+package handlers
+
+import "net/http"
+
+// noticeParam is the query parameter an action's redirect carries its
+// notice code in.
+const noticeParam = "notice"
+
+// noticeCode names one of the fixed lines noticeFor knows. An action
+// redirects with the code rather than the line, so nothing a client
+// puts in the URL reaches the page: a code noticeFor does not know
+// shows nothing.
+type noticeCode string
+
+// The codes of the actions on the webhook pages and of signing out.
+// Replay's codes, with the reasons a replay can be refused, and
+// resubmit's codes are defined beside those actions.
+const (
+	webhookCreated        noticeCode = "webhook-created"
+	webhookSaved          noticeCode = "webhook-saved"
+	webhookDeleted        noticeCode = "webhook-deleted"
+	entrypointAdded       noticeCode = "entrypoint-added"
+	entrypointDeleted     noticeCode = "entrypoint-deleted"
+	entrypointActivated   noticeCode = "entrypoint-activated"
+	entrypointDeactivated noticeCode = "entrypoint-deactivated"
+	targetAdded           noticeCode = "target-added"
+	targetSaved           noticeCode = "target-saved"
+	targetDeleted         noticeCode = "target-deleted"
+	targetActivated       noticeCode = "target-activated"
+	targetDeactivated     noticeCode = "target-deactivated"
+	signedOut             noticeCode = "signed-out"
+)
+
+// notice is the line templates/notice.html shows above a page to say
+// what an action did.
+type notice struct {
+	Text string
+
+	// Failed shows the line as an error: the action was refused.
+	Failed bool
+}
+
+// noticeFor returns the notice the request's URL names, or nil when it
+// names none or an unknown code.
+func noticeFor(r *http.Request) *notice {
+	n, ok := map[noticeCode]notice{
+		webhookCreated:        {Text: "Webhook created."},
+		webhookSaved:          {Text: "Webhook saved."},
+		webhookDeleted:        {Text: "Webhook deleted."},
+		entrypointAdded:       {Text: "Entrypoint added."},
+		entrypointDeleted:     {Text: "Entrypoint deleted."},
+		entrypointActivated:   {Text: "Entrypoint activated."},
+		entrypointDeactivated: {Text: "Entrypoint deactivated."},
+		targetAdded:           {Text: "Target added."},
+		targetSaved:           {Text: "Target saved."},
+		targetDeleted:         {Text: "Target deleted."},
+		targetActivated:       {Text: "Target activated."},
+		targetDeactivated:     {Text: "Target deactivated."},
+		signedOut:             {Text: "Signed out."},
+
+		replayQueued: {
+			Text: "Replay queued: a new delivery was created " +
+				"against the target's current configuration.",
+		},
+		replayTargetDeleted: {
+			Text: "Not replayed: the target this delivery was for " +
+				"has been deleted. Recreate the target, then replay.",
+			Failed: true,
+		},
+		replayTargetMissing: {
+			Text: "Not replayed: the target this delivery was for " +
+				"no longer exists.",
+			Failed: true,
+		},
+		replayTargetInactive: {
+			Text: "Not replayed: the target this delivery was for " +
+				"is deactivated. Activate it, then replay.",
+			Failed: true,
+		},
+		replayNotTerminal: {
+			Text:   "Not replayed: this delivery has not finished yet.",
+			Failed: true,
+		},
+		replayInFlight: {
+			Text: "Not replayed: a delivery of this event to this " +
+				"target is already in flight.",
+			Failed: true,
+		},
+
+		resubmitQueued: {
+			Text: "Resubmitted: a new event was created from the " +
+				"stored one and queued to every active target.",
+		},
+		resubmitNoTargets: {
+			Text: "Resubmitted: a new event was created, but this " +
+				"source has no active targets, so nothing was queued.",
+		},
+	}[noticeCode(r.URL.Query().Get(noticeParam))]
+	if !ok {
+		return nil
+	}
+
+	return &n
+}
+
+// withNotice returns path with code added as its notice.
+func withNotice(path string, code noticeCode) string {
+	return path + "?" + noticeParam + "=" + string(code)
+}

internal/handlers/profile.go

@@ -1,7 +1,6 @@
 package handlers
 
 import (
-	"context"
 	"net/http"
 
 	"github.com/go-chi/chi"
@@ -37,14 +36,14 @@ func (h *Handlers) HandlePasswordChange() http.HandlerFunc {
 		err := r.ParseForm()
 		if err != nil {
 			h.log.Error("failed to parse form", "error", err)
-			http.Error(w, "Bad request", http.StatusBadRequest)
+			h.renderError(w, r, http.StatusBadRequest)
 
 			return
 		}
 
 		successMessage, errorMessage, handled := h.applyPasswordChange(
-			r.Context(),
 			w,
+			r,
 			sessionUsername,
 			// PostFormValue, not FormValue: the credential must
 			// come from the body, never from the query string.
@@ -66,12 +65,12 @@ func (h *Handlers) HandlePasswordChange() http.HandlerFunc {
 // applyPasswordChange verifies the current password and, on success,
 // persists a fresh hash for the user, reusing the same helpers that
 // bootstrap the admin user. It returns the success and error messages
-// to display on the profile page. On an internal failure it writes a
-// 500 response itself and returns handled=false, signalling the caller
+// to display on the profile page. On an internal failure it writes the
+// error page itself and returns handled=false, signalling the caller
 // to stop without re-rendering the page.
 func (h *Handlers) applyPasswordChange(
-	ctx context.Context,
 	w http.ResponseWriter,
+	r *http.Request,
 	username, currentPassword, newPassword, confirmPassword string,
 ) (string, string, bool) {
 	// This endpoint verifies one password and hashes another, at
@@ -79,15 +78,10 @@ func (h *Handlers) applyPasswordChange(
 	// endpoint uses. The bound is per hash, not per endpoint: leaving
 	// this path outside it would leave a hole in it. The slot is held
 	// across both hashes.
-	release, ok := h.mw.BeginPasswordVerification(ctx)
+	release, ok := h.mw.BeginPasswordVerification(r.Context())
 	if !ok {
 		h.log.Warn("password verification capacity exhausted")
-		http.Error(
-			w,
-			"The server is busy verifying credentials. "+
-				"Please try again.",
-			http.StatusServiceUnavailable,
-		)
+		h.renderError(w, r, http.StatusServiceUnavailable)
 
 		return "", "", false
 	}
@@ -103,7 +97,7 @@ func (h *Handlers) applyPasswordChange(
 	).First(&user).Error
 	if err != nil {
 		h.serverError(
-			w, "failed to load user for password change", err,
+			w, r, "failed to load user for password change", err,
 		)
 
 		return "", "", false
@@ -113,7 +107,7 @@ func (h *Handlers) applyPasswordChange(
 		currentPassword, user.Password,
 	)
 	if err != nil {
-		h.serverError(w, "failed to verify password", err)
+		h.serverError(w, r, "failed to verify password", err)
 
 		return "", "", false
 	}
@@ -132,7 +126,7 @@ func (h *Handlers) applyPasswordChange(
 
 	hashedPassword, err := database.HashPassword(newPassword)
 	if err != nil {
-		h.serverError(w, "failed to hash new password", err)
+		h.serverError(w, r, "failed to hash new password", err)
 
 		return "", "", false
 	}
@@ -141,7 +135,7 @@ func (h *Handlers) applyPasswordChange(
 		"password", hashedPassword,
 	).Error
 	if err != nil {
-		h.serverError(w, "failed to update password", err)
+		h.serverError(w, r, "failed to update password", err)
 
 		return "", "", false
 	}
@@ -162,7 +156,7 @@ func (h *Handlers) profileOwnerOrDeny(
 ) (string, string, bool) {
 	requestedUsername := chi.URLParam(r, "username")
 	if requestedUsername == "" {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return "", "", false
 	}
@@ -172,7 +166,7 @@ func (h *Handlers) profileOwnerOrDeny(
 	// unexpected retrieval error.
 	sess, err := h.session.Get(r)
 	if err != nil {
-		h.serverError(w, "failed to get session", err)
+		h.serverError(w, r, "failed to get session", err)
 
 		return "", "", false
 	}
@@ -180,10 +174,7 @@ func (h *Handlers) profileOwnerOrDeny(
 	sessionUsername, ok := h.session.GetUsername(sess)
 	if !ok {
 		h.log.Error("authenticated session missing username")
-		http.Error(
-			w, "Internal server error",
-			http.StatusInternalServerError,
-		)
+		h.renderError(w, r, http.StatusInternalServerError)
 
 		return "", "", false
 	}
@@ -191,17 +182,14 @@ func (h *Handlers) profileOwnerOrDeny(
 	sessionUserID, ok := h.session.GetUserID(sess)
 	if !ok {
 		h.log.Error("authenticated session missing user ID")
-		http.Error(
-			w, "Internal server error",
-			http.StatusInternalServerError,
-		)
+		h.renderError(w, r, http.StatusInternalServerError)
 
 		return "", "", false
 	}
 
 	// Only allow users to act on their own profile.
 	if requestedUsername != sessionUsername {
-		http.Error(w, "Forbidden", http.StatusForbidden)
+		h.renderError(w, r, http.StatusForbidden)
 
 		return "", "", false
 	}

internal/handlers/profile_test.go

@@ -128,7 +128,9 @@ func TestUserRoute_Unauthenticated_RedirectedByMiddleware(t *testing.T) {
 
 	var sess *session.Session
 
-	app := newTestApp(t, &log, &cfg, &sess)
+	var h *handlers.Handlers
+
+	app := newTestApp(t, &log, &cfg, &sess, &h)
 	app.RequireStart()
 
 	t.Cleanup(app.RequireStop)
@@ -139,7 +141,7 @@ func TestUserRoute_Unauthenticated_RedirectedByMiddleware(t *testing.T) {
 
 	router := chi.NewRouter()
 	router.Route("/user/{username}", func(r chi.Router) {
-		r.Use(mw.CSRF())
+		r.Use(mw.CSRF(h.HandleErrorPage(http.StatusForbidden)))
 		r.Use(mw.RequireAuth())
 		r.Get("/", func(w http.ResponseWriter, _ *http.Request) {
 			handlerReached = true

internal/handlers/source_delete_test.go

@@ -15,6 +15,7 @@ import (
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
 	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/session"
 )
@@ -79,6 +80,10 @@ func seedTarget(
 // from a delete statement.
 var errInjectedDelete = errors.New("injected delete failure")
 
+// errInjectedSave is the failure failSaveOnTable reports from a
+// save of an existing row.
+var errInjectedSave = errors.New("injected save failure")
+
 // seedEntrypoint inserts an entrypoint for a webhook.
 func seedEntrypoint(
 	t *testing.T,
@@ -146,19 +151,42 @@ func failDeleteOnTable(
 	)
 }
 
+// failSaveOnTable is failDeleteOnTable for saves: every update of
+// an existing row in the named table fails.
+func failSaveOnTable(
+	t *testing.T,
+	db *database.Database,
+	table string,
+) {
+	t.Helper()
+
+	require.NoError(t, db.DB().Callback().Update().
+		Before("gorm:update").
+		Register(
+			"test:fail_save_"+table,
+			func(tx *gorm.DB) {
+				if tx.Statement.Table == table {
+					_ = tx.AddError(errInjectedSave)
+				}
+			},
+		),
+	)
+}
+
 // archivePathFor returns the archive database path the
-// delivery engine would use for a webhook: beside the webhook's
-// event database in the data directory.
+// delivery engine would use for a database target: beside the
+// webhook's event database in the data directory.
 func archivePathFor(
 	t *testing.T,
 	mgr *database.WebhookDBManager,
-	webhookID string,
+	wh *database.Webhook,
+	tgt *database.Target,
 ) string {
 	t.Helper()
 
 	return filepath.Join(
-		filepath.Dir(mgr.DBPath(webhookID)),
-		"archive-"+webhookID+".db",
+		filepath.Dir(mgr.DBPath(wh.ID)),
+		delivery.ArchiveFileName(wh.Name, tgt.Name, tgt.ID),
 	)
 }
 
@@ -195,8 +223,8 @@ func postRequest(
 
 // TestHandleSourceDelete_EvictsArchiveWriter proves that
 // deleting a webhook reaches the delivery engine and releases
-// the webhook's archive writer, exercised through the real
-// deletion handler rather than by calling the evictor directly.
+// the webhook's archive writers, exercised through the real
+// deletion handler rather than by calling the engine directly.
 func TestHandleSourceDelete_EvictsArchiveWriter(t *testing.T) {
 	t.Parallel()
 
@@ -204,7 +232,7 @@ func TestHandleSourceDelete_EvictsArchiveWriter(t *testing.T) {
 		h    *handlers.Handlers
 		sess *session.Session
 		db   *database.Database
-		ev   *recordingEvictor
+		ev   *recordingArchives
 	)
 
 	app := newTestApp(t, &h, &sess, &db, &ev)
@@ -254,9 +282,10 @@ func TestHandleSourceDelete_KeepsArchiveFile(t *testing.T) {
 	t.Cleanup(app.RequireStop)
 
 	wh := seedWebhook(t, db)
+	tgt := seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
 
 	// Place an archive file where the delivery engine would.
-	archivePath := archivePathFor(t, mgr, wh.ID)
+	archivePath := archivePathFor(t, mgr, wh, tgt)
 	require.NoError(
 		t,
 		writeArchivePlaceholder(archivePath),
@@ -411,7 +440,9 @@ func TestHandleSourceDelete_RemovesConfigAndEventDatabase(
 	h.HandleSourceDelete().ServeHTTP(w, req)
 
 	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(t, "/hooks", w.Header().Get("Location"))
+	assert.Equal(
+		t, "/hooks?notice=webhook-deleted", w.Header().Get("Location"),
+	)
 
 	assert.Equal(
 		t, int64(0),
@@ -435,68 +466,17 @@ func TestHandleSourceDelete_RemovesConfigAndEventDatabase(
 	)
 }
 
-// TestHandleTargetDelete_EvictsWhenLastDatabaseTargetGone
-// proves that removing the last database target releases the
-// archive writer.
-func TestHandleTargetDelete_EvictsWhenLastDatabaseTargetGone(
-	t *testing.T,
-) {
+// TestHandleTargetDelete_EvictsThatTarget proves that deleting a
+// database target releases that target's archive writer and no
+// other: the webhook's other database target keeps its own.
+func TestHandleTargetDelete_EvictsThatTarget(t *testing.T) {
 	t.Parallel()
 
 	var (
 		h    *handlers.Handlers
 		sess *session.Session
 		db   *database.Database
-		ev   *recordingEvictor
-	)
-
-	app := newTestApp(t, &h, &sess, &db, &ev)
-	app.RequireStart()
-
-	t.Cleanup(app.RequireStop)
-
-	wh := seedWebhook(t, db)
-	tgt := seedTarget(
-		t, db, wh.ID, database.TargetTypeDatabase,
-	)
-
-	cookies := authenticatedCookies(
-		t, sess, deleteTestUserID, deleteTestUsername,
-	)
-
-	req := postRequest(
-		"/hook/"+wh.ID+"/targets/"+tgt.ID+"/delete",
-		cookies,
-		map[string]string{
-			paramSourceID: wh.ID,
-			paramTargetID: tgt.ID,
-		},
-	)
-	w := httptest.NewRecorder()
-
-	h.HandleTargetDelete().ServeHTTP(w, req)
-
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, []string{wh.ID}, ev.Evicted(),
-		"removing the last database target should evict",
-	)
-}
-
-// TestHandleTargetDelete_KeepsWriterWhenDatabaseTargetRemains
-// proves that deleting one of several database targets leaves
-// the still-needed archive writer alone: the surviving target
-// keeps archiving to the same file, so the writer must stay.
-func TestHandleTargetDelete_KeepsWriterWhenDatabaseTargetRemains(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	var (
-		h    *handlers.Handlers
-		sess *session.Session
-		db   *database.Database
-		ev   *recordingEvictor
+		ev   *recordingArchives
 	)
 
 	app := newTestApp(t, &h, &sess, &db, &ev)
@@ -527,17 +507,17 @@ func TestHandleTargetDelete_KeepsWriterWhenDatabaseTargetRemains(
 	h.HandleTargetDelete().ServeHTTP(w, req)
 
 	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Empty(
-		t, ev.Evicted(),
-		"a second database target still needs the writer",
+	assert.Equal(
+		t, []string{doomed.ID}, ev.EvictedTargets(),
+		"deleting a database target should evict its writer",
 	)
+	assert.Empty(t, ev.Evicted(), "the webhook is not deleted")
 }
 
-// TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted proves
-// that deleting a target of an unrelated type leaves a
-// still-needed archive writer alone: the webhook's database
-// target is untouched, so its writer must stay.
-func TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted(
+// TestHandleTargetDelete_IgnoresAnotherWebhooksTarget proves that
+// a target id from the URL that is not a target of the webhook
+// deletes nothing and so evicts nothing.
+func TestHandleTargetDelete_IgnoresAnotherWebhooksTarget(
 	t *testing.T,
 ) {
 	t.Parallel()
@@ -546,7 +526,7 @@ func TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted(
 		h    *handlers.Handlers
 		sess *session.Session
 		db   *database.Database
-		ev   *recordingEvictor
+		ev   *recordingArchives
 	)
 
 	app := newTestApp(t, &h, &sess, &db, &ev)
@@ -555,19 +535,20 @@ func TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted(
 	t.Cleanup(app.RequireStop)
 
 	wh := seedWebhook(t, db)
-	seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
-	other := seedTarget(t, db, wh.ID, database.TargetTypeLog)
+	elsewhere := seedTarget(
+		t, db, seedWebhook(t, db).ID, database.TargetTypeDatabase,
+	)
 
 	cookies := authenticatedCookies(
 		t, sess, deleteTestUserID, deleteTestUsername,
 	)
 
 	req := postRequest(
-		"/hook/"+wh.ID+"/targets/"+other.ID+"/delete",
+		"/hook/"+wh.ID+"/targets/"+elsewhere.ID+"/delete",
 		cookies,
 		map[string]string{
 			paramSourceID: wh.ID,
-			paramTargetID: other.ID,
+			paramTargetID: elsewhere.ID,
 		},
 	)
 	w := httptest.NewRecorder()
@@ -576,7 +557,7 @@ func TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted(
 
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Empty(
-		t, ev.Evicted(),
-		"a surviving database target must keep its writer",
+		t, ev.EvictedTargets(),
+		"another webhook's target must not be evicted",
 	)
 }

internal/handlers/source_detail_test.go

@@ -241,3 +241,37 @@ func TestHandleSourceDetail_RendersNamedTargetFields(
 	assert.Contains(t, body, "(unavailable)")
 	assert.NotContains(t, body, "beak")
 }
+
+// TestHandleSourceDetail_FitsWideAndNarrowWindows pins the webhook
+// page's maximum width at 108rem (1728 px), half again the 72rem of
+// max-w-6xl that the webhook list and the event log use, so an
+// entrypoint URL fits on one line in a 1920-pixel window; and the
+// wrapping of its title row, so the buttons beside the title do not
+// push a phone-width window into scrolling sideways.
+func TestHandleSourceDetail_FitsWideAndNarrowWindows(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h    *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+	)
+
+	app := newTestApp(t, &h, &sess, &db)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+
+	body := renderSourceDetailPage(t, h, sess, wh.ID)
+
+	assert.Contains(
+		t, body,
+		`<div class="mx-auto px-6 py-8" style="max-width: 108rem"`,
+	)
+	assert.Contains(
+		t, body,
+		`<div class="flex flex-wrap justify-between items-center gap-2 mt-2">`,
+	)
+}

internal/handlers/source_management.go

@@ -149,13 +149,7 @@ func (h *Handlers) HandleSourceList() http.HandlerFunc {
 			"user_id = ?", userID,
 		).Order("created_at DESC").Find(&webhooks).Error
 		if err != nil {
-			h.log.Error(
-				"failed to list webhooks", "error", err,
-			)
-			http.Error(
-				w, "Internal server error",
-				http.StatusInternalServerError,
-			)
+			h.serverError(w, r, "failed to list webhooks", err)
 
 			return
 		}
@@ -249,9 +243,7 @@ func (h *Handlers) HandleSourceCreateSubmit() http.HandlerFunc {
 		// middleware, which runs before CSRF parses the form.
 		err := r.ParseForm()
 		if err != nil {
-			http.Error(
-				w, "Bad request", http.StatusBadRequest,
-			)
+			h.renderError(w, r, http.StatusBadRequest)
 
 			return
 		}
@@ -311,7 +303,7 @@ func (h *Handlers) createWebhookWithEntrypoint(
 
 	err := h.commitWebhook(webhook)
 	if err != nil {
-		h.serverError(w, "failed to create webhook", err)
+		h.serverError(w, r, "failed to create webhook", err)
 
 		return
 	}
@@ -330,7 +322,8 @@ func (h *Handlers) createWebhookWithEntrypoint(
 	)
 
 	http.Redirect(
-		w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+		w, r, withNotice("/hook/"+webhook.ID, webhookCreated),
+		http.StatusSeeOther,
 	)
 }
 
@@ -388,7 +381,7 @@ func (h *Handlers) HandleSourceDetail() http.HandlerFunc {
 			"id = ? AND user_id = ?", sourceID, userID,
 		).First(&webhook).Error
 		if err != nil {
-			http.NotFound(w, r)
+			h.renderError(w, r, http.StatusNotFound)
 
 			return
 		}
@@ -420,7 +413,7 @@ func (h *Handlers) renderSourceDetail(
 	if h.dbMgr.DBExists(webhook.ID) {
 		webhookDB, err := h.dbMgr.GetDB(webhook.ID)
 		if err != nil {
-			h.serverError(w, "failed to get webhook database", err)
+			h.serverError(w, r, "failed to get webhook database", err)
 
 			return
 		}
@@ -429,7 +422,7 @@ func (h *Handlers) renderSourceDetail(
 			webhookDB, webhook.ID, singleHTTPTargetID(targets),
 		)
 		if err != nil {
-			h.serverError(w, "failed to load recent events", err)
+			h.serverError(w, r, "failed to load recent events", err)
 
 			return
 		}
@@ -483,7 +476,7 @@ func (h *Handlers) HandleSourceEdit() http.HandlerFunc {
 			"id = ? AND user_id = ?", sourceID, userID,
 		).First(&webhook).Error
 		if err != nil {
-			http.NotFound(w, r)
+			h.renderError(w, r, http.StatusNotFound)
 
 			return
 		}
@@ -518,7 +511,7 @@ func (h *Handlers) HandleSourceEditSubmit() http.HandlerFunc {
 			"id = ? AND user_id = ?", sourceID, userID,
 		).First(&webhook).Error
 		if err != nil {
-			http.NotFound(w, r)
+			h.renderError(w, r, http.StatusNotFound)
 
 			return
 		}
@@ -527,9 +520,7 @@ func (h *Handlers) HandleSourceEditSubmit() http.HandlerFunc {
 		// middleware, which runs before CSRF parses the form.
 		err = r.ParseForm()
 		if err != nil {
-			http.Error(
-				w, "Bad request", http.StatusBadRequest,
-			)
+			h.renderError(w, r, http.StatusBadRequest)
 
 			return
 		}
@@ -559,6 +550,7 @@ func (h *Handlers) applyWebhookEdit(
 		return
 	}
 
+	oldName := webhook.Name
 	webhook.Name = name
 	webhook.Description = r.PostFormValue("description")
 
@@ -581,15 +573,49 @@ func (h *Handlers) applyWebhookEdit(
 
 	webhook.RetentionDays = retentionDays
 
-	err := h.db.DB().Save(webhook).Error
+	// A new name renames the archive files before it is saved (see
+	// delivery.Engine.Rename). If either step fails, they go back to
+	// the name that is still stored.
+	err := h.renameWebhookArchives(webhook.ID, oldName, webhook.Name)
+	if err == nil {
+		err = h.db.DB().Save(webhook).Error
+	}
+
 	if err != nil {
-		h.serverError(w, "failed to update webhook", err)
+		restoreErr := h.renameWebhookArchives(
+			webhook.ID, webhook.Name, oldName,
+		)
+		if restoreErr != nil {
+			h.log.Error(
+				"failed to rename archives back",
+				"webhook_id", webhook.ID,
+				"error", restoreErr,
+			)
+		}
+
+		if errors.Is(err, delivery.ErrArchiveNameTaken) {
+			data := map[string]any{
+				tmplKeyWebhook: webhook,
+				tmplKeyError: "Not saved: " + err.Error() +
+					". Move that archive out of the data directory, " +
+					"its .db together with any -wal and -shm beside " +
+					"it, then save again.",
+			}
+
+			w.WriteHeader(http.StatusConflict)
+			h.renderTemplate(w, r, "source_edit.html", data)
+
+			return
+		}
+
+		h.serverError(w, r, "failed to update webhook", err)
 
 		return
 	}
 
 	http.Redirect(
-		w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+		w, r, withNotice("/hook/"+webhook.ID, webhookSaved),
+		http.StatusSeeOther,
 	)
 }
 
@@ -613,7 +639,7 @@ func (h *Handlers) HandleSourceDelete() http.HandlerFunc {
 			"id = ? AND user_id = ?", sourceID, userID,
 		).First(&webhook).Error
 		if err != nil {
-			http.NotFound(w, r)
+			h.renderError(w, r, http.StatusNotFound)
 
 			return
 		}
@@ -640,7 +666,7 @@ func (h *Handlers) deleteWebhookResources(
 	// be removed by hand; deleted history cannot be recovered.
 	err := h.commitWebhookDeletion(&webhook)
 	if err != nil {
-		h.serverError(w, "failed to delete webhook", err)
+		h.serverError(w, r, "failed to delete webhook", err)
 
 		return
 	}
@@ -666,13 +692,15 @@ func (h *Handlers) deleteWebhookResources(
 		// redirecting as though everything succeeded: the file
 		// needs removing by hand, and the logged error names it.
 		h.serverError(
-			w, "failed to delete webhook event database", err,
+			w, r, "failed to delete webhook event database", err,
 		)
 
 		return
 	}
 
-	http.Redirect(w, r, "/hooks", http.StatusSeeOther)
+	http.Redirect(
+		w, r, withNotice("/hooks", webhookDeleted), http.StatusSeeOther,
+	)
 }
 
 // commitWebhookDeletion soft-deletes a webhook's entrypoints,
@@ -717,11 +745,11 @@ func (h *Handlers) commitWebhookDeletion(
 	return tx.Commit().Error
 }
 
-// evictArchiveWriter asks the delivery engine to drop its
-// cached archive writer for a webhook, closing the archive file
-// handle.
+// evictArchiveWriter asks the delivery engine to drop the cached
+// archive writers of a webhook's database targets, closing their
+// archive file handles.
 //
-// The archive database file is NOT deleted. Unlike the event
+// The archive database files are NOT deleted. Unlike the event
 // database — which is per-webhook working storage and is
 // hard-deleted with the webhook — an archive is explicitly
 // long-term storage that an operator may want to keep or move
@@ -729,50 +757,62 @@ func (h *Handlers) commitWebhookDeletion(
 // deleting a webhook would be a surprising and unrecoverable
 // data loss, so the file is left for the operator to handle.
 func (h *Handlers) evictArchiveWriter(webhookID string) {
-	if h.evictor == nil {
+	if h.archives == nil {
 		return
 	}
 
-	h.evictor.EvictWebhook(webhookID)
+	h.archives.EvictWebhook(webhookID)
 }
 
-// evictArchiveWriterIfUnused releases a webhook's archive
-// writer once the webhook has no database target left to feed
-// it.
-//
-// It is called after any child resource of a webhook is
-// deleted, and is correct without knowing which kind was: it
-// evicts only when no database target remains, so deleting one
-// of several database targets — or deleting an unrelated
-// target type — leaves a still-needed writer alone. When no
-// database target ever existed there is no writer and eviction
-// is a no-op. Soft-deleted targets are excluded by GORM's
-// default scope, so the row just deleted is not counted.
-func (h *Handlers) evictArchiveWriterIfUnused(webhookID string) {
-	var remaining int64
+// evictTargetArchiveWriter is evictArchiveWriter for one deleted
+// target, and leaves its archive file on disk for the same reason.
+// A target that is not a database target has no writer, and
+// evicting it does nothing.
+func (h *Handlers) evictTargetArchiveWriter(targetID string) {
+	if h.archives == nil {
+		return
+	}
+
+	h.archives.EvictTarget(targetID)
+}
+
+// renameWebhookArchives renames the archive file of every database
+// target of a webhook from the webhook name oldName to newName,
+// keeping each target's own name. It does nothing when the name is
+// unchanged. It tries every target even after one fails, so that
+// moving the archives back after a failed edit leaves none under the
+// new name, and returns every failure joined.
+func (h *Handlers) renameWebhookArchives(
+	webhookID, oldName, newName string,
+) error {
+	if h.archives == nil || oldName == newName {
+		return nil
+	}
+
+	var targets []database.Target
 
 	err := h.db.DB().
-		Model(&database.Target{}).
 		Where(
 			"webhook_id = ? AND type = ?",
 			webhookID, database.TargetTypeDatabase,
 		).
-		Count(&remaining).Error
+		Find(&targets).Error
 	if err != nil {
-		h.log.Error(
-			"failed to count remaining database targets",
-			"webhook_id", webhookID,
-			"error", err,
+		return err
+	}
+
+	var errs []error
+
+	for i := range targets {
+		err = h.archives.Rename(
+			targets[i].ID, newName, targets[i].Name,
 		)
-
-		return
+		if err != nil {
+			errs = append(errs, err)
+		}
 	}
 
-	if remaining > 0 {
-		return
-	}
-
-	h.evictArchiveWriter(webhookID)
+	return errors.Join(errs...)
 }
 
 // ownedWebhook resolves the request's sourceID parameter to a
@@ -810,7 +850,7 @@ func (h *Handlers) ownedWebhook(
 		"id = ? AND user_id = ?", sourceID, userID,
 	).First(&webhook).Error
 	if err != nil {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return database.Webhook{}, false
 	}
@@ -832,7 +872,7 @@ func (h *Handlers) HandleSourceLogs() http.HandlerFunc {
 			// Without the map every delivery renders through a
 			// zero redactor, so failing the page is the only
 			// safe answer.
-			h.serverError(w, "failed to load targets", err)
+			h.serverError(w, r, "failed to load targets", err)
 
 			return
 		}
@@ -840,7 +880,7 @@ func (h *Handlers) HandleSourceLogs() http.HandlerFunc {
 		page := h.parsePage(r)
 
 		evts, total, ok := h.loadEventsWithDeliveries(
-			w, webhook, targets, page,
+			w, r, webhook, targets, page,
 		)
 		if !ok {
 			return
@@ -851,31 +891,16 @@ func (h *Handlers) HandleSourceLogs() http.HandlerFunc {
 			totalPages++
 		}
 
-		// The banner a replay or resubmit POST redirected back
-		// with. The message comes from a fixed set keyed by the
-		// outcome code, never from the query string itself.
-		replayMsg, replayOK := replayOutcome(
-			r.URL.Query().Get(replayOutcomeParam),
-		)
-
-		resubmitMsg, resubmitOK := resubmitOutcome(
-			r.URL.Query().Get(resubmitOutcomeParam),
-		)
-
 		data := map[string]any{
-			tmplKeyWebhook:    &webhook,
-			"Events":          evts,
-			"ReplayMessage":   replayMsg,
-			"ReplayQueued":    replayOK,
-			"ResubmitMessage": resubmitMsg,
-			"ResubmitQueued":  resubmitOK,
-			"Page":            page,
-			"TotalPages":      totalPages,
-			"TotalEvents":     total,
-			"HasPrev":         page > 1,
-			"HasNext":         page < totalPages,
-			"PrevPage":        page - 1,
-			"NextPage":        page + 1,
+			tmplKeyWebhook: &webhook,
+			"Events":       evts,
+			"Page":         page,
+			"TotalPages":   totalPages,
+			"TotalEvents":  total,
+			"HasPrev":      page > 1,
+			"HasNext":      page < totalPages,
+			"PrevPage":     page - 1,
+			"NextPage":     page + 1,
 		}
 
 		h.renderTemplate(w, r, "source_logs.html", data)
@@ -950,6 +975,7 @@ func (h *Handlers) parsePage(r *http.Request) int {
 // caller must then render nothing further.
 func (h *Handlers) loadEventsWithDeliveries(
 	w http.ResponseWriter,
+	r *http.Request,
 	webhook database.Webhook,
 	targetMap map[string]eventLogTarget,
 	page int,
@@ -963,7 +989,7 @@ func (h *Handlers) loadEventsWithDeliveries(
 	webhookDB, err := h.dbMgr.GetDB(webhook.ID)
 	if err != nil {
 		h.serverError(
-			w, "failed to get webhook database", err,
+			w, r, "failed to get webhook database", err,
 		)
 
 		return nil, 0, false
@@ -1000,7 +1026,7 @@ func (h *Handlers) loadEventsWithDeliveries(
 	)
 	if err != nil {
 		h.serverError(
-			w, "failed to load delivery attempts", err,
+			w, r, "failed to load delivery attempts", err,
 		)
 
 		return nil, 0, false
@@ -1009,7 +1035,7 @@ func (h *Handlers) loadEventsWithDeliveries(
 	resubmits, err := resubmitCounts(webhookDB, eventIDs)
 	if err != nil {
 		h.serverError(
-			w, "failed to count event resubmissions", err,
+			w, r, "failed to count event resubmissions", err,
 		)
 
 		return nil, 0, false
@@ -1232,7 +1258,7 @@ func (h *Handlers) HandleEntrypointCreate() http.HandlerFunc {
 			"id = ? AND user_id = ?", sourceID, userID,
 		).First(&webhook).Error
 		if err != nil {
-			http.NotFound(w, r)
+			h.renderError(w, r, http.StatusNotFound)
 
 			return
 		}
@@ -1241,9 +1267,7 @@ func (h *Handlers) HandleEntrypointCreate() http.HandlerFunc {
 		// middleware, which runs before CSRF parses the form.
 		err = r.ParseForm()
 		if err != nil {
-			http.Error(
-				w, "Bad request", http.StatusBadRequest,
-			)
+			h.renderError(w, r, http.StatusBadRequest)
 
 			return
 		}
@@ -1259,13 +1283,14 @@ func (h *Handlers) HandleEntrypointCreate() http.HandlerFunc {
 
 		err = h.db.DB().Create(entrypoint).Error
 		if err != nil {
-			h.serverError(w, "failed to create entrypoint", err)
+			h.serverError(w, r, "failed to create entrypoint", err)
 
 			return
 		}
 
 		http.Redirect(
-			w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+			w, r, withNotice("/hook/"+webhook.ID, entrypointAdded),
+			http.StatusSeeOther,
 		)
 	}
 }
@@ -1290,7 +1315,7 @@ func (h *Handlers) HandleTargetCreate() http.HandlerFunc {
 			"id = ? AND user_id = ?", sourceID, userID,
 		).First(&webhook).Error
 		if err != nil {
-			http.NotFound(w, r)
+			h.renderError(w, r, http.StatusNotFound)
 
 			return
 		}
@@ -1299,9 +1324,7 @@ func (h *Handlers) HandleTargetCreate() http.HandlerFunc {
 		// middleware, which runs before CSRF parses the form.
 		err = r.ParseForm()
 		if err != nil {
-			http.Error(
-				w, "Bad request", http.StatusBadRequest,
-			)
+			h.renderError(w, r, http.StatusBadRequest)
 
 			return
 		}
@@ -1372,13 +1395,14 @@ func (h *Handlers) processTargetCreate(
 
 	err = h.db.DB().Create(target).Error
 	if err != nil {
-		h.serverError(w, "failed to create target", err)
+		h.serverError(w, r, "failed to create target", err)
 
 		return
 	}
 
 	http.Redirect(
-		w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+		w, r, withNotice("/hook/"+webhook.ID, targetAdded),
+		http.StatusSeeOther,
 	)
 }
 
@@ -1466,7 +1490,7 @@ func (h *Handlers) buildTargetConfig(
 	case database.TargetTypeSlack:
 		return h.buildSlackTargetConfig(w, r, in.URL)
 	case database.TargetTypeDatabase:
-		return h.buildDatabaseTargetConfig(w, in.Expiry)
+		return h.buildDatabaseTargetConfig(w, r, in.Expiry)
 	case database.TargetTypeLog:
 		return "", nil
 	default:
@@ -1516,7 +1540,7 @@ func (h *Handlers) buildHTTPTargetConfig(
 		return "", err
 	}
 
-	return marshalTargetConfig(w, delivery.HTTPTargetConfig{
+	return h.marshalTargetConfig(w, r, delivery.HTTPTargetConfig{
 		URL:     in.URL,
 		Headers: headers,
 		Timeout: timeout,
@@ -1538,7 +1562,7 @@ func (h *Handlers) buildSlackTargetConfig(
 		return "", err
 	}
 
-	return marshalTargetConfig(w, delivery.SlackTargetConfig{
+	return h.marshalTargetConfig(w, r, delivery.SlackTargetConfig{
 		WebhookURL: targetURL,
 	})
 }
@@ -1578,11 +1602,22 @@ func (h *Handlers) validateTargetURL(
 			"url", delivery.MaskURL(targetURL),
 			"error", err,
 		)
-		http.Error(
-			w,
-			"Invalid target URL: "+err.Error(),
-			http.StatusBadRequest,
-		)
+
+		msg := "Invalid target URL: " + err.Error()
+
+		// Only a private or reserved address's refusal says how
+		// to allow it. Metadata refusals never do: link-local and
+		// the other unconditional metadata addresses cannot be
+		// opened, and the default blocklist's public addresses,
+		// which listing does open, hand out credentials.
+		if errors.Is(err, delivery.ErrBlockedPrivateOrReservedIP) {
+			msg += ". Private and reserved addresses are refused " +
+				"by default; the server's ALLOWED_EGRESS_CIDRS " +
+				"setting allows named networks (see \"Allowing " +
+				"egress to your own network\" in the README)."
+		}
+
+		http.Error(w, msg, http.StatusBadRequest)
 
 		return err
 	}
@@ -1592,16 +1627,14 @@ func (h *Handlers) validateTargetURL(
 
 // marshalTargetConfig serialises a target configuration for storage,
 // writing a 500 itself if it cannot.
-func marshalTargetConfig(
+func (h *Handlers) marshalTargetConfig(
 	w http.ResponseWriter,
+	r *http.Request,
 	cfg any,
 ) (string, error) {
 	configBytes, err := json.Marshal(cfg)
 	if err != nil {
-		http.Error(
-			w, "Internal server error",
-			http.StatusInternalServerError,
-		)
+		h.serverError(w, r, "failed to encode target config", err)
 
 		return "", err
 	}
@@ -1617,6 +1650,7 @@ func marshalTargetConfig(
 // expiry yields an empty config (the keep-forever default).
 func (h *Handlers) buildDatabaseTargetConfig(
 	w http.ResponseWriter,
+	r *http.Request,
 	expiry string,
 ) (string, error) {
 	expiry = strings.TrimSpace(expiry)
@@ -1635,8 +1669,8 @@ func (h *Handlers) buildDatabaseTargetConfig(
 		return "", err
 	}
 
-	return marshalTargetConfig(
-		w, map[string]any{"expiry": expiry},
+	return h.marshalTargetConfig(
+		w, r, map[string]any{"expiry": expiry},
 	)
 }
 
@@ -1646,30 +1680,33 @@ func (h *Handlers) HandleEntrypointDelete() http.HandlerFunc {
 		"entrypointID", &database.Entrypoint{},
 		"failed to delete entrypoint",
 		nil,
+		entrypointDeleted,
 	)
 }
 
-// HandleTargetDelete handles deleting a target. Deleting the
-// last database target of a webhook leaves its archive writer
-// with nothing to write, so the writer is evicted and its
-// handle closed; the archive file is left on disk.
+// HandleTargetDelete handles deleting a target. A deleted
+// database target's archive writer is evicted and its handle
+// closed; the archive file is left on disk.
 func (h *Handlers) HandleTargetDelete() http.HandlerFunc {
 	return h.deleteChildResource(
 		"targetID", &database.Target{},
 		"failed to delete target",
-		h.evictArchiveWriterIfUnused,
+		h.evictTargetArchiveWriter,
+		targetDeleted,
 	)
 }
 
 // deleteChildResource returns a handler that deletes a child
 // resource (entrypoint or target) belonging to a webhook. The
-// optional afterDelete hook runs with the webhook's id once the
-// delete has succeeded, before the redirect.
+// optional afterDelete hook runs with the child's id once the
+// delete has removed it, before the redirect, which carries done as
+// its notice.
 func (h *Handlers) deleteChildResource(
 	idParam string,
 	model any,
 	errMsg string,
-	afterDelete func(webhookID string),
+	afterDelete func(childID string),
+	done noticeCode,
 ) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		userID, ok := h.getUserID(r)
@@ -1690,7 +1727,7 @@ func (h *Handlers) deleteChildResource(
 			"id = ? AND user_id = ?", sourceID, userID,
 		).First(&webhook).Error
 		if err != nil {
-			http.NotFound(w, r)
+			h.renderError(w, r, http.StatusNotFound)
 
 			return
 		}
@@ -1700,22 +1737,20 @@ func (h *Handlers) deleteChildResource(
 			childID, webhook.ID,
 		).Delete(model)
 		if result.Error != nil {
-			h.log.Error(errMsg, "error", result.Error)
-			http.Error(
-				w, "Internal server error",
-				http.StatusInternalServerError,
-			)
+			h.serverError(w, r, errMsg, result.Error)
 
 			return
 		}
 
-		if afterDelete != nil {
-			afterDelete(webhook.ID)
+		// Only for a row this webhook really had: the id came from
+		// the URL and may name another webhook's child.
+		if afterDelete != nil && result.RowsAffected > 0 {
+			afterDelete(childID)
 		}
 
 		http.Redirect(
 			w, r,
-			"/hook/"+webhook.ID,
+			withNotice("/hook/"+webhook.ID, done),
 			http.StatusSeeOther,
 		)
 	}
@@ -1726,7 +1761,7 @@ func (h *Handlers) deleteChildResource(
 func (h *Handlers) HandleEntrypointToggle() http.HandlerFunc {
 	return h.toggleChildResource(
 		"entrypointID",
-		func(webhookID, childID string) error {
+		func(webhookID, childID string) (bool, error) {
 			var ep database.Entrypoint
 
 			err := h.db.DB().Where(
@@ -1734,14 +1769,15 @@ func (h *Handlers) HandleEntrypointToggle() http.HandlerFunc {
 				childID, webhookID,
 			).First(&ep).Error
 			if err != nil {
-				return err
+				return false, err
 			}
 
 			ep.Active = !ep.Active
 
-			return h.db.DB().Save(&ep).Error
+			return ep.Active, h.db.DB().Save(&ep).Error
 		},
 		"failed to toggle entrypoint",
+		entrypointActivated, entrypointDeactivated,
 	)
 }
 
@@ -1749,7 +1785,7 @@ func (h *Handlers) HandleEntrypointToggle() http.HandlerFunc {
 func (h *Handlers) HandleTargetToggle() http.HandlerFunc {
 	return h.toggleChildResource(
 		"targetID",
-		func(webhookID, childID string) error {
+		func(webhookID, childID string) (bool, error) {
 			var tgt database.Target
 
 			err := h.db.DB().Where(
@@ -1757,23 +1793,27 @@ func (h *Handlers) HandleTargetToggle() http.HandlerFunc {
 				childID, webhookID,
 			).First(&tgt).Error
 			if err != nil {
-				return err
+				return false, err
 			}
 
 			tgt.Active = !tgt.Active
 
-			return h.db.DB().Save(&tgt).Error
+			return tgt.Active, h.db.DB().Save(&tgt).Error
 		},
 		"failed to toggle target",
+		targetActivated, targetDeactivated,
 	)
 }
 
 // toggleChildResource returns a handler that toggles the active
-// state of a child resource belonging to a webhook.
+// state of a child resource belonging to a webhook. toggleFn returns
+// the new state, and the redirect carries activated or deactivated as
+// its notice to match.
 func (h *Handlers) toggleChildResource(
 	idParam string,
-	toggleFn func(webhookID, childID string) error,
+	toggleFn func(webhookID, childID string) (bool, error),
 	errMsg string,
+	activated, deactivated noticeCode,
 ) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		userID, ok := h.getUserID(r)
@@ -1794,25 +1834,26 @@ func (h *Handlers) toggleChildResource(
 			"id = ? AND user_id = ?", sourceID, userID,
 		).First(&webhook).Error
 		if err != nil {
-			http.NotFound(w, r)
+			h.renderError(w, r, http.StatusNotFound)
 
 			return
 		}
 
-		err = toggleFn(webhook.ID, childID)
+		active, err := toggleFn(webhook.ID, childID)
 		if err != nil {
-			h.log.Error(errMsg, "error", err)
-			http.Error(
-				w, "Internal server error",
-				http.StatusInternalServerError,
-			)
+			h.serverError(w, r, errMsg, err)
 
 			return
 		}
 
+		done := deactivated
+		if active {
+			done = activated
+		}
+
 		http.Redirect(
 			w, r,
-			"/hook/"+webhook.ID,
+			withNotice("/hook/"+webhook.ID, done),
 			http.StatusSeeOther,
 		)
 	}

internal/handlers/source_management_test.go

@@ -187,6 +187,7 @@ func storedRetentionDays(
 type sourceTestEnv struct {
 	handlers *handlers.Handlers
 	db       *database.Database
+	archives *recordingArchives
 	cookies  []*http.Cookie
 }
 
@@ -199,7 +200,9 @@ func setupSourceTest(t *testing.T) *sourceTestEnv {
 
 	var db *database.Database
 
-	app := newTestApp(t, &h, &sess, &db)
+	var archives *recordingArchives
+
+	app := newTestApp(t, &h, &sess, &db, &archives)
 	app.RequireStart()
 
 	t.Cleanup(app.RequireStop)
@@ -207,6 +210,7 @@ func setupSourceTest(t *testing.T) *sourceTestEnv {
 	return &sourceTestEnv{
 		handlers: h,
 		db:       db,
+		archives: archives,
 		cookies: authenticatedCookies(
 			t, sess, sourceTestUserID, "sourceuser",
 		),
@@ -498,6 +502,184 @@ func TestHandleSourceEditSubmit_EmptyRetentionLeavesValueUnchanged(
 	assert.Equal(t, 7, storedRetentionDays(t, env.db, wh.ID))
 }
 
+// renamedWebhookName is the name the rename tests give a webhook.
+const renamedWebhookName = "Renamed"
+
+// TestHandleSourceEditSubmit_RenamesArchives proves that a save
+// that keeps the webhook's name renames nothing, and that renaming a
+// webhook renames the archive of each of its database targets and
+// asks nothing of its other targets.
+func TestHandleSourceEditSubmit_RenamesArchives(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(t, env.db, 7)
+	first := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+	second := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+	seedTarget(t, env.db, wh.ID, database.TargetTypeLog)
+
+	w := submitEdit(t, env, wh, "")
+	require.Equal(t, http.StatusSeeOther, w.Code)
+	assert.Empty(t, env.archives.Renames())
+
+	wh.Name = renamedWebhookName
+
+	w = submitEdit(t, env, wh, "")
+	require.Equal(t, http.StatusSeeOther, w.Code)
+
+	assert.ElementsMatch(
+		t,
+		[]archiveRename{
+			{first.ID, renamedWebhookName, first.Name},
+			{second.ID, renamedWebhookName, second.Name},
+		},
+		env.archives.Renames(),
+	)
+}
+
+// TestHandleSourceEditSubmit_FailedRenameKeepsTheName proves that a
+// webhook whose archive cannot be renamed keeps its stored name, so
+// the name on disk and the name in the UI do not part, and that the
+// handler puts back what it may already have moved.
+func TestHandleSourceEditSubmit_FailedRenameKeepsTheName(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(t, env.db, 7)
+	tgt := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+
+	env.archives.FailRenames(tgt.ID, errInjectedRename)
+
+	oldName := wh.Name
+	wh.Name = renamedWebhookName
+
+	w := submitEdit(t, env, wh, "")
+	require.Equal(t, http.StatusInternalServerError, w.Code)
+
+	var stored database.Webhook
+
+	require.NoError(
+		t, env.db.DB().First(&stored, "id = ?", wh.ID).Error,
+	)
+	assert.Equal(t, oldName, stored.Name)
+
+	assert.Equal(
+		t,
+		[]archiveRename{
+			{tgt.ID, renamedWebhookName, tgt.Name},
+			{tgt.ID, oldName, tgt.Name},
+		},
+		env.archives.Renames(),
+	)
+}
+
+// TestHandleSourceEditSubmit_FailedSaveRenamesBack proves that when
+// the archive is renamed but the new name cannot be saved, the
+// archive is renamed back to the stored name and the stored name
+// stays.
+func TestHandleSourceEditSubmit_FailedSaveRenamesBack(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(t, env.db, 7)
+	tgt := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+
+	failSaveOnTable(t, env.db, "webhooks")
+
+	oldName := wh.Name
+	wh.Name = renamedWebhookName
+
+	w := submitEdit(t, env, wh, "")
+	require.Equal(t, http.StatusInternalServerError, w.Code)
+
+	var stored database.Webhook
+
+	require.NoError(
+		t, env.db.DB().First(&stored, "id = ?", wh.ID).Error,
+	)
+	assert.Equal(t, oldName, stored.Name)
+
+	assert.Equal(
+		t,
+		[]archiveRename{
+			{tgt.ID, renamedWebhookName, tgt.Name},
+			{tgt.ID, oldName, tgt.Name},
+		},
+		env.archives.Renames(),
+	)
+}
+
+// TestHandleSourceEditSubmit_FailedRenameRenamesTheOthersBack proves
+// that when a webhook has two database targets and only the second
+// one's archive cannot be renamed, the first is renamed back and the
+// stored name stays. Every target is tried in each direction, so this
+// holds whichever order the two come in.
+func TestHandleSourceEditSubmit_FailedRenameRenamesTheOthersBack(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(t, env.db, 7)
+	first := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+	second := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+
+	env.archives.FailRenames(second.ID, errNameTaken)
+
+	oldName := wh.Name
+	wh.Name = renamedWebhookName
+
+	w := submitEdit(t, env, wh, "")
+	require.Equal(t, http.StatusConflict, w.Code)
+
+	var stored database.Webhook
+
+	require.NoError(
+		t, env.db.DB().First(&stored, "id = ?", wh.ID).Error,
+	)
+	assert.Equal(t, oldName, stored.Name)
+
+	assert.ElementsMatch(
+		t,
+		[]archiveRename{
+			{first.ID, renamedWebhookName, first.Name},
+			{second.ID, renamedWebhookName, second.Name},
+			{first.ID, oldName, first.Name},
+			{second.ID, oldName, second.Name},
+		},
+		env.archives.Renames(),
+	)
+}
+
+// TestHandleSourceEditSubmit_ArchiveNameTaken proves that when a file
+// already has an archive's new name, the edit is refused with an
+// error naming that file, and the webhook keeps its stored name.
+func TestHandleSourceEditSubmit_ArchiveNameTaken(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(t, env.db, 7)
+	tgt := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+
+	env.archives.FailRenames(tgt.ID, errNameTaken)
+
+	oldName := wh.Name
+	wh.Name = renamedWebhookName
+
+	w := submitEdit(t, env, wh, "")
+	require.Equal(t, http.StatusConflict, w.Code)
+	assert.Contains(t, w.Body.String(), "archive-taken.db")
+
+	var stored database.Webhook
+
+	require.NoError(
+		t, env.db.DB().First(&stored, "id = ?", wh.ID).Error,
+	)
+	assert.Equal(t, oldName, stored.Name)
+}
+
 // TestSourceEditForm_ForeverWebhookRoundTrips walks the exact path that
 // the removed max="365" cap used to break: render the edit form for a
 // retain-forever webhook, confirm the pre-filled sentinel is not capped

internal/handlers/target_edit.go

@@ -1,6 +1,7 @@
 package handlers
 
 import (
+	"errors"
 	"net/http"
 
 	"github.com/go-chi/chi"
@@ -88,9 +89,7 @@ func (h *Handlers) HandleTargetEditSubmit() http.HandlerFunc {
 		// middleware, which runs before CSRF parses the form.
 		err := r.ParseForm()
 		if err != nil {
-			http.Error(
-				w, "Bad request", http.StatusBadRequest,
-			)
+			h.renderError(w, r, http.StatusBadRequest)
 
 			return
 		}
@@ -152,21 +151,69 @@ func (h *Handlers) applyTargetEdit(
 		target.MaxRetries = retries
 	}
 
+	oldName := target.Name
 	target.Name = name
 	target.Config = configJSON
 
-	err = h.db.DB().Save(target).Error
+	// A new name renames the archive file before it is saved (see
+	// delivery.Engine.Rename). If either step fails, it goes back to
+	// the name that is still stored.
+	err = h.renameTargetArchive(target, webhook.Name, oldName, name)
+	if err == nil {
+		err = h.db.DB().Save(target).Error
+	}
+
 	if err != nil {
-		h.serverError(w, "failed to update target", err)
+		restoreErr := h.renameTargetArchive(
+			target, webhook.Name, name, oldName,
+		)
+		if restoreErr != nil {
+			h.log.Error(
+				"failed to rename archive back",
+				"target_id", target.ID,
+				"error", restoreErr,
+			)
+		}
+
+		if errors.Is(err, delivery.ErrArchiveNameTaken) {
+			http.Error(
+				w,
+				"Not saved: "+err.Error()+
+					". Move that archive out of the data directory, "+
+					"its .db together with any -wal and -shm beside "+
+					"it, then save again.",
+				http.StatusConflict,
+			)
+
+			return
+		}
+
+		h.serverError(w, r, "failed to update target", err)
 
 		return
 	}
 
 	http.Redirect(
-		w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+		w, r, withNotice("/hook/"+webhook.ID, targetSaved),
+		http.StatusSeeOther,
 	)
 }
 
+// renameTargetArchive renames a database target's archive file from
+// the target name oldName to newName. It does nothing when the name
+// is unchanged; other target types have no archive.
+func (h *Handlers) renameTargetArchive(
+	target *database.Target,
+	webhookName, oldName, newName string,
+) error {
+	if h.archives == nil || oldName == newName ||
+		target.Type != database.TargetTypeDatabase {
+		return nil
+	}
+
+	return h.archives.Rename(target.ID, webhookName, newName)
+}
+
 // renderTargetEdit renders the target edit page with an optional
 // error message.
 func (h *Handlers) renderTargetEdit(
@@ -220,7 +267,7 @@ func (h *Handlers) ownedTarget(
 		chi.URLParam(r, "targetID"), webhook.ID,
 	).First(&target).Error
 	if err != nil {
-		http.NotFound(w, r)
+		h.renderError(w, r, http.StatusNotFound)
 
 		return database.Webhook{}, nil, false
 	}

internal/handlers/target_edit_test.go

@@ -635,3 +635,100 @@ func assertWebhookOfAnotherUser404s(
 
 	assert.Equal(t, http.StatusNotFound, w.Code)
 }
+
+// renamedTargetName is the name the rename tests give a target.
+const renamedTargetName = "Long Term"
+
+// TestHandleTargetEditSubmit_RenamesArchive proves that renaming a
+// database target renames its archive, that a save that keeps the
+// name renames nothing, that a target of another type has no archive
+// to rename, and that a target whose archive cannot be renamed keeps
+// its stored name. When a file already has the archive's new name,
+// the edit is refused with an error naming that file.
+func TestHandleTargetEditSubmit_RenamesArchive(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(t, env.db, 7)
+	archive := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+	rename := url.Values{"name": {renamedTargetName}}
+
+	w := submitTargetEdit(env, wh.ID, archive.ID, rename)
+	require.Equal(t, http.StatusSeeOther, w.Code, w.Body.String())
+	assert.Equal(
+		t,
+		[]archiveRename{{archive.ID, wh.Name, renamedTargetName}},
+		env.archives.Renames(),
+	)
+
+	w = submitTargetEdit(env, wh.ID, archive.ID, rename)
+	require.Equal(t, http.StatusSeeOther, w.Code, w.Body.String())
+	assert.Len(
+		t, env.archives.Renames(), 1,
+		"a save that keeps the name renames nothing",
+	)
+
+	httpWebhook, httpTarget := seedHTTPTarget(t, env, "", "")
+
+	w = submitTargetEdit(
+		env, httpWebhook.ID, httpTarget.ID,
+		editForm(editOriginalURL, "", ""),
+	)
+	require.Equal(t, http.StatusSeeOther, w.Code, w.Body.String())
+	assert.Len(
+		t, env.archives.Renames(), 1,
+		"an HTTP target has no archive to rename",
+	)
+
+	again := url.Values{"name": {"Again"}}
+
+	env.archives.FailRenames(archive.ID, errInjectedRename)
+
+	w = submitTargetEdit(env, wh.ID, archive.ID, again)
+	require.Equal(t, http.StatusInternalServerError, w.Code)
+	assert.Equal(
+		t, renamedTargetName, storedTarget(t, env, archive.ID).Name,
+		"a target whose archive was not renamed keeps its name",
+	)
+
+	env.archives.FailRenames(archive.ID, errNameTaken)
+
+	w = submitTargetEdit(env, wh.ID, archive.ID, again)
+	require.Equal(t, http.StatusConflict, w.Code)
+	assert.Contains(t, w.Body.String(), "archive-taken.db")
+	assert.Equal(
+		t, renamedTargetName, storedTarget(t, env, archive.ID).Name,
+	)
+}
+
+// TestHandleTargetEditSubmit_FailedSaveRenamesBack proves that when a
+// database target's archive is renamed but the new name cannot be
+// saved, the archive is renamed back to the stored name and the
+// stored name stays.
+func TestHandleTargetEditSubmit_FailedSaveRenamesBack(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(t, env.db, 7)
+	archive := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+
+	failSaveOnTable(t, env.db, "targets")
+
+	form := url.Values{}
+	form.Set("name", renamedTargetName)
+
+	w := submitTargetEdit(env, wh.ID, archive.ID, form)
+	require.Equal(t, http.StatusInternalServerError, w.Code)
+	assert.Equal(
+		t, archive.Name, storedTarget(t, env, archive.ID).Name,
+	)
+
+	assert.Equal(
+		t,
+		[]archiveRename{
+			{archive.ID, wh.Name, renamedTargetName},
+			{archive.ID, wh.Name, archive.Name},
+		},
+		env.archives.Renames(),
+	)
+}

internal/handlers/target_private_refusal_test.go

@@ -0,0 +1,116 @@
+package handlers_test
+
+import (
+	"net/http"
+	"net/url"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// privateRefusalHint is the sentence that tells an operator a private
+// destination is refused on purpose, and how to allow one.
+const privateRefusalHint = "Private and reserved addresses are " +
+	"refused by default; the server's ALLOWED_EGRESS_CIDRS setting " +
+	"allows named networks (see \"Allowing egress to your own " +
+	"network\" in the README)."
+
+// TestTargetRefusal_PrivateDestinationSaysHowToAllowIt covers both
+// target types that take a URL, on add and on edit.
+func TestTargetRefusal_PrivateDestinationSaysHowToAllowIt(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+
+	targetTypes := []database.TargetType{
+		database.TargetTypeHTTP,
+		database.TargetTypeSlack,
+	}
+
+	for _, targetType := range targetTypes {
+		t.Run(string(targetType), func(t *testing.T) {
+			t.Parallel()
+
+			webhook := seedWebhookWithRetention(t, env.db, 30)
+			targetsPath := "/hook/" + webhook.ID + "/targets"
+
+			form := url.Values{}
+			form.Set("name", "private")
+			form.Set("type", string(targetType))
+			form.Set("url", editBlockedURL)
+
+			added := serveTarget(
+				env, http.MethodPost, targetsPath, form,
+			)
+			assert.Equal(t, http.StatusBadRequest, added.Code)
+			assert.Contains(
+				t, added.Body.String(), privateRefusalHint,
+			)
+
+			form.Set("url", editOriginalURL)
+
+			created := serveTarget(
+				env, http.MethodPost, targetsPath, form,
+			)
+			require.Equal(
+				t, http.StatusSeeOther, created.Code,
+				created.Body.String(),
+			)
+
+			targets := targetsForWebhook(t, env.db, webhook.ID)
+			require.Len(t, targets, 1)
+
+			form.Set("url", editBlockedURL)
+
+			edited := submitTargetEdit(
+				env, webhook.ID, targets[0].ID, form,
+			)
+			assert.Equal(t, http.StatusBadRequest, edited.Code)
+			assert.Contains(
+				t, edited.Body.String(), privateRefusalHint,
+			)
+		})
+	}
+}
+
+// TestTargetRefusal_MetadataDestinationDoesNotSayHowToAllowIt: no
+// setting opens a link-local address, and Azure's WireServer hands out
+// VM credentials, so neither refusal points at the setting.
+func TestTargetRefusal_MetadataDestinationDoesNotSayHowToAllowIt(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+
+	metadataURLs := map[string]string{
+		"link-local": "http://169.254.169.254/latest/meta-data/",
+		"wireserver": "http://168.63.129.16/?comp=versions",
+	}
+
+	for name, metadataURL := range metadataURLs {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			webhook := seedWebhookWithRetention(t, env.db, 30)
+
+			form := url.Values{}
+			form.Set("name", "metadata")
+			form.Set("type", string(database.TargetTypeHTTP))
+			form.Set("url", metadataURL)
+
+			w := serveTarget(
+				env, http.MethodPost,
+				"/hook/"+webhook.ID+"/targets", form,
+			)
+			assert.Equal(t, http.StatusBadRequest, w.Code)
+			assert.NotContains(
+				t, w.Body.String(), privateRefusalHint,
+			)
+		})
+	}
+}

internal/handlers/webhook.go

@@ -88,14 +88,14 @@ func (h *Handlers) processWebhookRequest(
 
 	headersJSON, err := json.Marshal(r.Header)
 	if err != nil {
-		h.serverError(w, "failed to serialize headers", err)
+		h.receiverError(w, "failed to serialize headers", err)
 
 		return
 	}
 
 	targets, err := h.loadActiveTargets(entrypoint.WebhookID)
 	if err != nil {
-		h.serverError(w, "failed to query targets", err)
+		h.receiverError(w, "failed to query targets", err)
 
 		return
 	}
@@ -196,7 +196,7 @@ func (h *Handlers) createAndDeliverEvent(
 		targets,
 	)
 	if err != nil {
-		h.serverError(w, "failed to store webhook event", err)
+		h.receiverError(w, "failed to store webhook event", err)
 
 		return
 	}
@@ -204,6 +204,19 @@ func (h *Handlers) createAndDeliverEvent(
 	h.finishWebhookResponse(w, event, entrypoint, tasks)
 }
 
+// receiverError logs an error and answers the sender with a plain-text
+// 500. The receiver's answers are for programs, so it never sends the
+// error page the web UI uses.
+func (h *Handlers) receiverError(
+	w http.ResponseWriter, msg string, err error,
+) {
+	h.log.Error(msg, "error", err)
+	http.Error(
+		w, "Internal server error",
+		http.StatusInternalServerError,
+	)
+}
+
 // eventSource carries the fields a new event is built from. The
 // receiver fills it from the live request; the resubmit handler fills
 // it from a stored event. Both then go through createAndFanOut, so an

internal/metrics/metrics.go

@@ -3,17 +3,18 @@
 // deliveries are attempted, how they end, how long they take, how
 // deep the queues are, and how many circuit breakers are open.
 //
-// The inbound HTTP metrics come from the go-http-metrics recorder in
-// internal/middleware and land on prometheus.DefaultRegisterer. These
-// collectors register there too, so both surfaces are gathered by the
-// one promhttp handler mounted on the authenticated /metrics route.
+// It also builds the registry the authenticated /metrics route
+// serves. In production, these collectors, the inbound HTTP metrics
+// recorded in internal/middleware, and the Go runtime and process
+// collectors all register on that one registry, never on Prometheus's
+// global default.
 package metrics
 
 import (
-	"sync"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 	"sneak.berlin/go/webhooker/internal/database"
 )
@@ -57,25 +58,31 @@ var knownTargetTypes = []database.TargetType{
 	database.TargetTypeSlack,
 }
 
-// defaultSet is the process-wide metric set, registered on the same
-// registry the HTTP middleware and the /metrics handler already use.
-// It is built on first use rather than in an init so that a test
-// binary that never touches metrics never registers them.
+// NewRegistry returns the registry /metrics serves, carrying the Go
+// runtime and process collectors that Prometheus's global default
+// registry carries, so the go_* and process_* series stay in the
+// scrape.
 //
-//nolint:gochecknoglobals // one process-wide registration, by design
-var defaultSet = sync.OnceValue(func() *Set {
-	return New(prometheus.DefaultRegisterer)
-})
+// A registry of its own, rather than the global default, is what lets
+// two dependency graphs in one process — two tests, say — each
+// register their collectors without the second registration
+// panicking.
+func NewRegistry() *prometheus.Registry {
+	reg := prometheus.NewRegistry()
+	reg.MustRegister(
+		collectors.NewGoCollector(),
+		collectors.NewProcessCollector(
+			collectors.ProcessCollectorOpts{},
+		),
+	)
 
-// Default returns the process-wide metric set.
-func Default() *Set {
-	return defaultSet()
+	return reg
 }
 
 // Set is one registered group of webhooker's delivery collectors.
-// Production uses the single Default set; tests build their own
-// against a private registry so assertions are not disturbed by
-// deliveries other tests are making concurrently.
+// Production builds one on the registry /metrics serves; tests build
+// one on a registry of their own so they can gather what their own
+// deliveries recorded.
 type Set struct {
 	eventsReceived      prometheus.Counter
 	deliveryAttempts    *prometheus.CounterVec
@@ -93,7 +100,7 @@ type Set struct {
 // New registers a full set of delivery collectors on reg and returns
 // it. It panics if reg already holds them, which is the intended
 // behaviour for a duplicate registration.
-func New(reg prometheus.Registerer) *Set {
+func New(reg *prometheus.Registry) *Set {
 	factory := promauto.With(reg)
 
 	s := &Set{

internal/middleware/csrf.go

@@ -19,7 +19,7 @@ func CSRFToken(r *http.Request) string {
 // key to sign a CSRF cookie and validates a masked token submitted via
 // the "csrf_token" form field (or the "X-CSRF-Token" header) on
 // POST/PUT/PATCH/DELETE requests. Requests with an invalid or missing
-// token receive a 403 Forbidden response.
+// token are logged and answered by forbidden, which must write the 403.
 //
 // The middleware detects the client-facing transport protocol
 // per-request via reqtls.IsTLS, the single TLS predicate the session
@@ -36,7 +36,9 @@ func CSRFToken(r *http.Request) string {
 // Two gorilla/csrf instances are maintained — one with Secure cookies
 // (for TLS) and one without (for plaintext HTTP) — because the
 // csrf.Secure option is set at creation time, not per-request.
-func (m *Middleware) CSRF() func(http.Handler) http.Handler {
+func (m *Middleware) CSRF(
+	forbidden http.Handler,
+) func(http.Handler) http.Handler {
 	csrfErrorHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		// CSRF is registered ahead of RequireAuth on every route
 		// group that uses it, so this WARN is reachable by an
@@ -57,7 +59,7 @@ func (m *Middleware) CSRF() func(http.Handler) http.Handler {
 			"remote_addr", r.RemoteAddr,
 			"reason", csrf.FailureReason(r),
 		)
-		http.Error(w, "Forbidden - invalid CSRF token", http.StatusForbidden)
+		forbidden.ServeHTTP(w, r)
 	})
 
 	key := m.session.GetKey()

internal/middleware/csrf_test.go

@@ -18,6 +18,12 @@ import (
 // csrfCookieName is the gorilla/csrf cookie name.
 const csrfCookieName = "_gorilla_csrf"
 
+// forbidden stands in for the error page the server hands CSRF to
+// answer a refused request with.
+func forbidden(w http.ResponseWriter, _ *http.Request) {
+	w.WriteHeader(http.StatusForbidden)
+}
+
 // csrfGetToken performs a GET request through the CSRF middleware
 // and returns the token and cookies.
 func csrfGetToken(
@@ -98,7 +104,7 @@ func TestCSRF_GETSetsToken(t *testing.T) {
 
 	var gotToken string
 
-	handler := m.CSRF()(http.HandlerFunc(
+	handler := m.CSRF(http.HandlerFunc(forbidden))(http.HandlerFunc(
 		func(_ http.ResponseWriter, r *http.Request) {
 			gotToken = middleware.CSRFToken(r)
 		},
@@ -120,7 +126,7 @@ func TestCSRF_POSTWithValidToken(t *testing.T) {
 	t.Parallel()
 
 	m, _ := testMiddleware(t, config.EnvironmentDev)
-	csrfMW := m.CSRF()
+	csrfMW := m.CSRF(http.HandlerFunc(forbidden))
 
 	getReq := httptest.NewRequestWithContext(
 		context.Background(),
@@ -152,7 +158,7 @@ func csrfPOSTWithoutTokenTest(
 	t.Helper()
 
 	m, _ := testMiddleware(t, env)
-	csrfMW := m.CSRF()
+	csrfMW := m.CSRF(http.HandlerFunc(forbidden))
 
 	// GET to establish the CSRF cookie
 	getHandler := csrfMW(http.HandlerFunc(
@@ -209,7 +215,7 @@ func TestCSRF_POSTWithInvalidToken(t *testing.T) {
 	t.Parallel()
 
 	m, _ := testMiddleware(t, config.EnvironmentDev)
-	csrfMW := m.CSRF()
+	csrfMW := m.CSRF(http.HandlerFunc(forbidden))
 
 	// GET to establish the CSRF cookie
 	getHandler := csrfMW(http.HandlerFunc(
@@ -265,7 +271,7 @@ func TestCSRF_GETDoesNotValidate(t *testing.T) {
 
 	var called bool
 
-	handler := m.CSRF()(http.HandlerFunc(
+	handler := m.CSRF(http.HandlerFunc(forbidden))(http.HandlerFunc(
 		func(_ http.ResponseWriter, _ *http.Request) {
 			called = true
 		},
@@ -328,7 +334,7 @@ func csrfTookStrictPath(
 	t.Helper()
 
 	m, _ := testMiddleware(t, env)
-	csrfMW := m.CSRF()
+	csrfMW := m.CSRF(http.HandlerFunc(forbidden))
 
 	newReq := func(method string) *http.Request {
 		r := httptest.NewRequestWithContext(
@@ -477,7 +483,7 @@ func TestCSRF_ProdMode_PlaintextHTTP_POSTWithValidToken(
 	t.Parallel()
 
 	m, _ := testMiddleware(t, config.EnvironmentProd)
-	csrfMW := m.CSRF()
+	csrfMW := m.CSRF(http.HandlerFunc(forbidden))
 
 	getReq := httptest.NewRequestWithContext(
 		context.Background(),
@@ -517,7 +523,7 @@ func TestCSRF_ProdMode_BehindProxy_POSTWithValidToken(
 	t.Parallel()
 
 	m, _ := testMiddleware(t, config.EnvironmentProd)
-	csrfMW := m.CSRF()
+	csrfMW := m.CSRF(http.HandlerFunc(forbidden))
 
 	getReq := httptest.NewRequestWithContext(
 		context.Background(),
@@ -562,7 +568,7 @@ func TestCSRF_ProdMode_DirectTLS_POSTWithValidToken(
 	t.Parallel()
 
 	m, _ := testMiddleware(t, config.EnvironmentProd)
-	csrfMW := m.CSRF()
+	csrfMW := m.CSRF(http.HandlerFunc(forbidden))
 
 	getReq := httptest.NewRequestWithContext(
 		context.Background(),

internal/middleware/export_test.go

@@ -10,8 +10,7 @@ import (
 
 // MetricsMiddlewareForTest builds the metrics recording middleware
 // against a caller-supplied recorder, so a test can gather from its
-// own Prometheus registry rather than the process-wide default one
-// that Middleware.Metrics uses.
+// own Prometheus registry without building a whole Middleware.
 func MetricsMiddlewareForTest(
 	rec httpmetrics.Recorder,
 ) func(http.Handler) http.Handler {

internal/middleware/logbound_test.go

@@ -260,7 +260,9 @@ func logSites() map[string]logSite {
 			) http.Handler {
 				t.Helper()
 
-				return m.CSRF()(unreachable(t))
+				return m.CSRF(http.HandlerFunc(forbidden))(
+					unreachable(t),
+				)
 			},
 			send:       postNoToken,
 			wantStatus: http.StatusForbidden,

internal/middleware/metrics.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/go-chi/chi"
 	httpmetrics "github.com/slok/go-http-metrics/metrics"
-	prommetrics "github.com/slok/go-http-metrics/metrics/prometheus"
 	ghmm "github.com/slok/go-http-metrics/middleware"
 	"github.com/slok/go-http-metrics/middleware/std"
 )
@@ -151,17 +150,17 @@ func (r boundedLabelRecorder) AddInflightRequests(
 
 var _ httpmetrics.Recorder = boundedLabelRecorder{}
 
-// Metrics returns middleware that records Prometheus HTTP metrics on
-// the default registry, which is the one the /metrics route gathers.
+// Metrics returns middleware that records Prometheus HTTP metrics
+// with the Middleware's one recorder, which New builds on the registry
+// the /metrics route serves and NewForTest on a registry of its own.
+// Every call reuses that recorder, so any number of routers can
+// install it.
 func (s *Middleware) Metrics() func(http.Handler) http.Handler {
-	return metricsMiddleware(
-		prommetrics.NewRecorder(prommetrics.Config{}),
-	)
+	return metricsMiddleware(s.metricsRecorder)
 }
 
 // metricsMiddleware builds the recording middleware against a given
-// recorder, so tests can gather from a registry of their own instead
-// of the process-wide default.
+// recorder, so tests can gather from a registry of their own.
 func metricsMiddleware(
 	rec httpmetrics.Recorder,
 ) func(http.Handler) http.Handler {

internal/middleware/metrics_test.go

@@ -57,9 +57,8 @@ const (
 // Server.setupWebhookRoutes inside it. That ordering is the whole
 // defect, so a test that flattens it would prove nothing.
 //
-// The recorder writes to a registry of the test's own rather than the
-// process-wide default one, so each test observes only its own
-// traffic.
+// The recorder writes to a registry of the test's own, so each test
+// observes only its own traffic.
 func metricsTestRouter(
 	t *testing.T,
 	receiverLimit int,
@@ -455,3 +454,29 @@ func TestMetrics_StatusAndSizeStillRecorded(t *testing.T) {
 		"the interceptor must still count written bytes",
 	)
 }
+
+// TestMetrics_WorksOnNewForTestMiddleware pins that a Middleware built
+// by NewForTest has a recorder of its own: its Metrics() serves a
+// request instead of panicking, and a second one does not collide
+// with the first.
+func TestMetrics_WorksOnNewForTestMiddleware(t *testing.T) {
+	t.Parallel()
+
+	log := slog.New(slog.DiscardHandler)
+	cfg := &config.Config{Environment: "prod"}
+	ok := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		_, _ = w.Write([]byte(okBody))
+	})
+
+	for range 2 {
+		h := middleware.NewForTest(log, cfg, nil).Metrics()(ok)
+
+		req := httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, okRoute, nil,
+		)
+		w := httptest.NewRecorder()
+		h.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusOK, w.Code)
+	}
+}

internal/middleware/middleware.go

@@ -14,6 +14,9 @@ import (
 	"github.com/go-chi/chi"
 	"github.com/go-chi/chi/middleware"
 	"github.com/go-chi/cors"
+	"github.com/prometheus/client_golang/prometheus"
+	httpmetrics "github.com/slok/go-http-metrics/metrics"
+	prommetrics "github.com/slok/go-http-metrics/metrics/prometheus"
 	"go.uber.org/fx"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/globals"
@@ -149,10 +152,11 @@ const (
 type MiddlewareParams struct {
 	fx.In
 
-	Logger  *logger.Logger
-	Globals *globals.Globals
-	Config  *config.Config
-	Session *session.Session
+	Logger   *logger.Logger
+	Globals  *globals.Globals
+	Config   *config.Config
+	Session  *session.Session
+	Registry *prometheus.Registry
 }
 
 // Middleware provides HTTP middleware for logging, CORS, auth, and
@@ -162,6 +166,14 @@ type Middleware struct {
 	params  *MiddlewareParams
 	session *session.Session
 
+	// metricsRecorder records the inbound HTTP metrics. New builds
+	// it on the registry /metrics serves, NewForTest on a registry
+	// of its own. Either way it is built once per Middleware and
+	// Metrics reuses it, because building it registers its
+	// collectors, and a second registration on the same registry
+	// panics.
+	metricsRecorder httpmetrics.Recorder
+
 	// loginGuard counts failed credential verifications and bounds
 	// concurrent password hashing. It is built on first use so that
 	// every construction path gets one; see guard().
@@ -180,6 +192,9 @@ func New(
 	s.params = &params
 	s.log = params.Logger.Get()
 	s.session = params.Session
+	s.metricsRecorder = prommetrics.NewRecorder(
+		prommetrics.Config{Registry: params.Registry},
+	)
 
 	return s, nil
 }

internal/middleware/recoverer.go

@@ -109,7 +109,8 @@ func (w *recoverResponseWriter) Unwrap() http.ResponseWriter {
 
 // Recoverer returns middleware that turns a handler panic into one
 // structured ERROR record and a 500, rather than a dropped
-// connection.
+// connection. The 500 is page when page is not nil, and plain text
+// when it is nil or when page panics before writing anything.
 //
 // It replaces chi's middleware.Recoverer, which does neither on a
 // current Go release. chi v1.5.5's pretty-printer scans the stack for
@@ -136,9 +137,13 @@ func (w *recoverResponseWriter) Unwrap() http.ResponseWriter {
 //
 // Unlike http.Error on its own, it deletes any Set-Cookie the handler
 // set before panicking, because a request that failed must not hand
-// the client a credential; every other header is left to http.Error.
+// the client a credential. It touches no other header: when page
+// answers, every other header the handler set goes out with it, apart
+// from any page sets itself; otherwise they are left to http.Error.
 // See https://git.eeqj.de/sneak/webhooker/issues/193.
-func (s *Middleware) Recoverer() func(http.Handler) http.Handler {
+func (s *Middleware) Recoverer(
+	page http.Handler,
+) func(http.Handler) http.Handler {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(
 			w http.ResponseWriter,
@@ -171,6 +176,14 @@ func (s *Middleware) Recoverer() func(http.Handler) http.Handler {
 
 				rw.Header().Del("Set-Cookie")
 
+				if page != nil {
+					s.servePage(rw, r, page)
+				}
+
+				if rw.committed {
+					return
+				}
+
 				http.Error(
 					rw,
 					http.StatusText(
@@ -185,6 +198,27 @@ func (s *Middleware) Recoverer() func(http.Handler) http.Handler {
 	}
 }
 
+// servePage answers with page. A panic in page itself is logged and
+// recovered here, so the Recoverer can still send its plain 500.
+func (s *Middleware) servePage(
+	w http.ResponseWriter,
+	r *http.Request,
+	page http.Handler,
+) {
+	defer func() {
+		rvr := recover()
+		if rvr != nil {
+			s.log.Error("error page panic",
+				"panic", logfield.Truncate(
+					fmt.Sprint(rvr), maxPanicValueBytes,
+				),
+			)
+		}
+	}()
+
+	page.ServeHTTP(w, r)
+}
+
 // logPanic writes the record. Every field it can grow is truncated to
 // a fixed budget, so MaxPanicLogLineBytes holds.
 //

internal/middleware/recoverer_test.go

@@ -76,7 +76,7 @@ func newRecovererProbe(
 	// Logging outside so the recovered 500 is the status it records.
 	router.Use(chimw.RequestID)
 	router.Use(m.Logging())
-	router.Use(m.Recoverer())
+	router.Use(m.Recoverer(nil))
 	router.Get("/probe", handler)
 
 	serverErrors := new(bytes.Buffer)
@@ -637,7 +637,7 @@ func TestRecovererKeepsResponseControllerWorking(t *testing.T) {
 
 	m, _ := capturingMiddleware(t)
 
-	handler := m.Recoverer()(http.HandlerFunc(
+	handler := m.Recoverer(nil)(http.HandlerFunc(
 		func(w http.ResponseWriter, _ *http.Request) {
 			_, _ = w.Write([]byte("chunk"))
 
@@ -672,3 +672,59 @@ func TestRecovererKeepsResponseControllerWorking(t *testing.T) {
 	assert.Equal(t, http.StatusOK, resp.StatusCode)
 	assert.Equal(t, "chunk", string(body))
 }
+
+// TestRecovererAnswersWithThePage covers a recoverer given a page:
+// the panic is logged as before, and the 500 is that page.
+func TestRecovererAnswersWithThePage(t *testing.T) {
+	t.Parallel()
+
+	m, logs := capturingMiddleware(t)
+
+	page := http.HandlerFunc(
+		func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusInternalServerError)
+			_, _ = w.Write([]byte("the error page"))
+		},
+	)
+
+	w := httptest.NewRecorder()
+	m.Recoverer(page)(http.HandlerFunc(panicProbe)).ServeHTTP(
+		w, httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, "/", nil,
+		),
+	)
+
+	assert.Equal(t, http.StatusInternalServerError, w.Code)
+	assert.Equal(t, "the error page", w.Body.String())
+	assert.Contains(t, logs.String(), `"msg":"handler panic"`)
+	assert.Contains(t, logs.String(), panicMarker)
+}
+
+// TestRecovererFallsBackWhenThePagePanics covers a page that panics
+// before writing anything: both panics are logged, and the client
+// still gets the plain 500.
+func TestRecovererFallsBackWhenThePagePanics(t *testing.T) {
+	t.Parallel()
+
+	m, logs := capturingMiddleware(t)
+
+	const pagePanic = "QQERRORPAGEPANICQQ"
+
+	page := http.HandlerFunc(
+		func(http.ResponseWriter, *http.Request) {
+			panic(pagePanic)
+		},
+	)
+
+	w := httptest.NewRecorder()
+	m.Recoverer(page)(http.HandlerFunc(panicProbe)).ServeHTTP(
+		w, httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, "/", nil,
+		),
+	)
+
+	assert.Equal(t, http.StatusInternalServerError, w.Code)
+	assert.Equal(t, "Internal Server Error\n", w.Body.String())
+	assert.Contains(t, logs.String(), panicMarker)
+	assert.Contains(t, logs.String(), pagePanic)
+}

internal/middleware/testing.go

@@ -3,12 +3,17 @@ package middleware
 import (
 	"log/slog"
 
+	"github.com/prometheus/client_golang/prometheus"
+	prommetrics "github.com/slok/go-http-metrics/metrics/prometheus"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/session"
 )
 
 // NewForTest creates a Middleware with the minimum dependencies
 // needed for testing. This bypasses the fx lifecycle.
+//
+// Its metrics recorder writes to a fresh registry of its own, so
+// Metrics() works on it and two of them never collide.
 func NewForTest(
 	log *slog.Logger,
 	cfg *config.Config,
@@ -20,5 +25,8 @@ func NewForTest(
 			Config: cfg,
 		},
 		session: sess,
+		metricsRecorder: prommetrics.NewRecorder(
+			prommetrics.Config{Registry: prometheus.NewRegistry()},
+		),
 	}
 }

internal/resetpw/resetpw_test.go

@@ -24,6 +24,7 @@ import (
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/healthcheck"
 	"sneak.berlin/go/webhooker/internal/logger"
+	"sneak.berlin/go/webhooker/internal/metrics"
 	"sneak.berlin/go/webhooker/internal/middleware"
 	"sneak.berlin/go/webhooker/internal/resetpw"
 	"sneak.berlin/go/webhooker/internal/session"
@@ -131,9 +132,15 @@ type noopNotifier struct{}
 
 func (n *noopNotifier) Notify([]delivery.Task) {}
 
-type noopEvictor struct{}
+type noopArchives struct{}
 
-func (n *noopEvictor) EvictWebhook(string) {}
+func (n *noopArchives) EvictWebhook(string) {}
+
+func (n *noopArchives) EvictTarget(string) {}
+
+func (n *noopArchives) Rename(_, _, _ string) error {
+	return nil
+}
 
 // newServerApp starts the real login path against dir: the handlers,
 // the middleware that bounds password verification, the session store
@@ -162,7 +169,9 @@ func newServerApp(
 			healthcheck.New,
 			session.New,
 			func() delivery.Notifier { return &noopNotifier{} },
-			func() delivery.WebhookEvictor { return &noopEvictor{} },
+			func() delivery.Archives { return &noopArchives{} },
+			metrics.NewRegistry,
+			metrics.New,
 			middleware.New,
 			delivery.NewGuard,
 			handlers.New,

internal/server/error_page_test.go

@@ -0,0 +1,238 @@
+package server_test
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strconv"
+	"testing"
+
+	"github.com/getsentry/sentry-go"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/config"
+	"sneak.berlin/go/webhooker/internal/server"
+)
+
+// The link back the error page offers: to the webhook list for a
+// signed-in user, to sign-in for anyone else.
+const (
+	backToWebhooks = `<a href="/hooks" class="btn-secondary">` +
+		`Back to webhooks</a>`
+	backToSignIn = `<a href="/pages/login" class="btn-primary">` +
+		`Sign in</a>`
+)
+
+// assertErrorPage checks that w is the error page for status, in the
+// normal layout, offering link.
+func assertErrorPage(
+	t *testing.T,
+	w *httptest.ResponseRecorder,
+	status int,
+	link string,
+) {
+	t.Helper()
+
+	body := w.Body.String()
+
+	assert.Equal(t, status, w.Code)
+	assert.Equal(
+		t, "text/html; charset=utf-8", w.Header().Get("Content-Type"),
+	)
+	assert.Equal(t, "no-store", w.Header().Get("Cache-Control"))
+	assert.Contains(t, body, `<nav class="app-bar"`)
+	assert.Contains(
+		t, body, strconv.Itoa(status)+" "+http.StatusText(status),
+	)
+	assert.Contains(t, body, link)
+}
+
+func TestErrorPage_DeletedWebhook(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	userID, _ := env.seedUser(t, "owner", "somepassword")
+	cookies := env.authCookies(t, userID, "owner")
+
+	wh := env.seedWebhook(t, userID)
+	require.NoError(t, env.db.DB().Delete(wh).Error)
+
+	w := env.get("/hook/"+wh.ID, cookies)
+
+	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
+}
+
+func TestErrorPage_DeletedTarget(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	userID, _ := env.seedUser(t, "owner", "somepassword")
+	cookies := env.authCookies(t, userID, "owner")
+
+	wh := env.seedWebhook(t, userID)
+	tgt := env.seedTarget(t, wh.ID)
+	require.NoError(t, env.db.DB().Delete(tgt).Error)
+
+	w := env.get(
+		"/hook/"+wh.ID+"/targets/"+tgt.ID+"/edit", cookies,
+	)
+
+	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
+}
+
+// TestErrorPage_ShowsNoNotice pins that a notice code in the URL of a
+// page that fails is not shown above the error.
+func TestErrorPage_ShowsNoNotice(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	userID, _ := env.seedUser(t, "owner", "somepassword")
+	cookies := env.authCookies(t, userID, "owner")
+
+	w := env.get("/hook/no-such-webhook?notice=webhook-saved", cookies)
+
+	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
+	assert.NotContains(t, w.Body.String(), "Webhook saved.")
+}
+
+func TestErrorPage_UnknownPath(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	userID, _ := env.seedUser(t, "owner", "somepassword")
+	cookies := env.authCookies(t, userID, "owner")
+
+	assertErrorPage(
+		t, env.get("/no-such-page", nil),
+		http.StatusNotFound, backToSignIn,
+	)
+
+	// Outside every route group there is no form token, so the
+	// page leaves out the logout form rather than offer one that
+	// would be refused.
+	w := env.get("/no-such-page", cookies)
+	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
+	assert.NotContains(t, w.Body.String(), `action="/pages/logout"`)
+
+	// Inside a route group the page has a token, and logout works.
+	wh := env.seedWebhook(t, userID)
+	w = env.get("/hook/"+wh.ID+"/no-such-page", cookies)
+	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
+	assert.Contains(t, w.Body.String(), `action="/pages/logout"`)
+}
+
+func TestErrorPage_BadCSRFToken(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	form := url.Values{}
+	form.Set("username", "someone")
+	form.Set("password", "irrelevant")
+	form.Set("csrf_token", "not-a-token")
+
+	assertErrorPage(
+		t, env.post("/pages/login", form, nil),
+		http.StatusForbidden, backToSignIn,
+	)
+
+	userID, _ := env.seedUser(t, "owner", "somepassword")
+	cookies := env.authCookies(t, userID, "owner")
+	wh := env.seedWebhook(t, userID)
+
+	edit := url.Values{}
+	edit.Set("name", "renamed")
+
+	assertErrorPage(
+		t, env.post("/hook/"+wh.ID+"/edit", edit, cookies),
+		http.StatusForbidden, backToWebhooks,
+	)
+}
+
+// TestErrorPage_PanicOnAdminPage sends a panicking handler in an
+// admin page route group through the real router, with error
+// tracking on: the client gets the 500 error page, and the tracker
+// still gets the panic, once. The same panic outside the admin page
+// route groups keeps the plain 500.
+func TestErrorPage_PanicOnAdminPage(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	transport := &captureTransport{}
+
+	opts := server.SentryClientOptionsForTest(
+		"https://public@sentry.invalid/1", "webhooker-test",
+	)
+	opts.Transport = transport
+
+	client, err := sentry.NewClient(opts)
+	require.NoError(t, err)
+
+	serve := func(router http.Handler, path string) *httptest.ResponseRecorder {
+		req := httptest.NewRequestWithContext(
+			sentry.SetHubOnContext(
+				context.Background(),
+				sentry.NewHub(client, sentry.NewScope()),
+			),
+			http.MethodGet, path, nil,
+		)
+
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+
+		return w
+	}
+
+	w := serve(
+		server.NewRouterWithPageProbeForTest(
+			env.log.Get(), env.cfg, env.mw, env.hnd,
+			true, panicProbeHandler,
+		),
+		server.PageProbePattern,
+	)
+	assertErrorPage(t, w, http.StatusInternalServerError, backToSignIn)
+
+	w = serve(
+		server.NewRouterWithProbeForTest(
+			env.log.Get(), env.cfg, env.mw, env.hnd,
+			true, panicProbeHandler,
+		),
+		server.ProbePattern,
+	)
+	assert.Equal(t, http.StatusInternalServerError, w.Code)
+	assert.Equal(t, "Internal Server Error\n", w.Body.String())
+
+	require.Len(t, transport.events, 2)
+
+	for _, event := range transport.events {
+		assert.Contains(t, marshalEvent(t, event), panicProbeMarker)
+	}
+}
+
+// TestErrorPage_ReceiverStaysPlain pins that the error page is for
+// the web UI only: a sender posting to an entrypoint that does not
+// exist still gets the plain-text answer.
+func TestErrorPage_ReceiverStaysPlain(t *testing.T) {
+	t.Parallel()
+
+	// newTestEnv leaves the receiver rate limit at zero, which
+	// refuses every request before it reaches the receiver.
+	env := newTestEnvWithConfig(t, &config.Config{
+		DataDir:           t.TempDir(),
+		Environment:       config.EnvironmentDev,
+		ReceiverRateLimit: 10,
+	})
+
+	w := env.post(
+		"/h/0b8f3c1e-7d2a-4e6b-9f15-3a9c2d4e6f70", url.Values{}, nil,
+	)
+
+	assert.Equal(t, http.StatusNotFound, w.Code)
+	assert.Equal(t, "404 page not found\n", w.Body.String())
+}

internal/server/export_test.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/getsentry/sentry-go"
+	"github.com/go-chi/chi"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/middleware"
@@ -101,3 +102,39 @@ func NewRouterWithProbeForTest(
 
 	return s.router
 }
+
+// PageProbePattern is where NewRouterWithPageProbeForTest serves its
+// probe: inside the /pages route group, the admin page group a
+// request reaches without signing in.
+const PageProbePattern = "/pages/probe"
+
+// NewRouterWithPageProbeForTest is NewRouterWithProbeForTest with the
+// probe added to the /pages route group once SetupRoutes has built
+// it, so the probe runs behind that group's own middleware exactly as
+// the group's real routes do.
+func NewRouterWithPageProbeForTest(
+	log *slog.Logger,
+	cfg *config.Config,
+	mw *middleware.Middleware,
+	h *handlers.Handlers,
+	sentryEnabled bool,
+	probe http.HandlerFunc,
+) http.Handler {
+	s := &Server{
+		log:    log,
+		mw:     mw,
+		h:      h,
+		params: ServerParams{Config: cfg},
+	}
+	s.sentryEnabled.Store(sentryEnabled)
+	s.SetupRoutes()
+
+	for _, route := range s.router.Routes() {
+		pages, ok := route.SubRoutes.(chi.Router)
+		if ok && route.Pattern == "/pages/*" {
+			pages.Get("/probe", probe)
+		}
+	}
+
+	return s.router
+}

internal/server/routes.go

@@ -7,7 +7,6 @@ import (
 	sentryhttp "github.com/getsentry/sentry-go/http"
 	"github.com/go-chi/chi"
 	"github.com/go-chi/chi/middleware"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"sneak.berlin/go/webhooker/static"
 )
 
@@ -15,9 +14,10 @@ import (
 // bytes) for form POST endpoints. 1 MB is generous for any form
 // submission while preventing abuse from oversized payloads.
 //
-// Every route group below installs MaxBodySize(maxFormBodySize) as
-// its FIRST middleware, ahead of both CSRF and RequireAuth. Both
-// orderings are deliberate.
+// The four admin page route groups below (/pages, /user/{username},
+// /hooks and /hook/{sourceID}) install MaxBodySize(maxFormBodySize)
+// right after their recoverer and error reporting, ahead of both CSRF
+// and RequireAuth. Both orderings are deliberate.
 //
 // Ahead of CSRF because gorilla/csrf parses the form. The cap has to
 // be installed before anything reads the body, or the parse runs
@@ -46,6 +46,14 @@ const requestTimeout = 60 * time.Second
 // server's router.
 func (s *Server) SetupRoutes() {
 	s.router = chi.NewRouter()
+
+	// An unknown path gets the error page. Registered before the
+	// global middleware, because chi wraps a not-found handler in the
+	// middleware already on its router, which would then run twice.
+	// The route groups below wrap it in their own middleware the same
+	// way; running theirs twice is harmless.
+	s.router.NotFound(s.h.HandleErrorPage(http.StatusNotFound))
+
 	s.setupGlobalMiddleware()
 	s.setupRoutes()
 }
@@ -69,23 +77,33 @@ func (s *Server) setupGlobalMiddleware() {
 	// Panic recovery, deliberately here rather than first. It has to
 	// run inside every middleware that observes the response, so the
 	// 500 it writes is the status the access log records and the
-	// metrics count, and outside the sentryhttp handler below, whose
+	// metrics count, and outside the sentryhttp handler, whose
 	// Repanic option needs something further out to catch what it
 	// re-raises. chi's own middleware.Recoverer held the first slot
 	// until it was measured: on a current Go release it crashes
 	// inside its stack pretty-printer instead of recovering, so the
 	// connection dropped and the original panic was never reported.
 	// See https://git.eeqj.de/sneak/webhooker/issues/187.
-	s.router.Use(s.mw.Recoverer())
+	s.recoverPanics(s.router, nil)
+}
+
+// recoverPanics installs on r the recoverer, answering a panic with
+// page (a plain 500 when page is nil), and inside it the Sentry error
+// reporting (if SENTRY_DSN is set). Repanic is true so panics still
+// bubble up to the recoverer.
+//
+// Each admin page route group installs its own, with the error page,
+// as its first middleware. A panic there is logged, reported and
+// answered inside the group and never reaches the global recoverer,
+// which keeps the plain 500 for every other route.
+func (s *Server) recoverPanics(r chi.Router, page http.Handler) {
+	r.Use(s.mw.Recoverer(page))
 
-	// Sentry error reporting (if SENTRY_DSN is set). Repanic is
-	// true so panics still bubble up to the Recoverer middleware
-	// registered immediately above.
 	if s.sentryEnabled.Load() {
 		sentryHandler := sentryhttp.New(sentryhttp.Options{
 			Repanic: true,
 		})
-		s.router.Use(sentryHandler.Handle)
+		r.Use(sentryHandler.Handle)
 	}
 }
 
@@ -130,12 +148,7 @@ func (s *Server) setupRoutes() {
 	if s.params.Config.MetricsAuthEnabled() {
 		s.router.Group(func(r chi.Router) {
 			r.Use(s.mw.MetricsAuth())
-			r.Get(
-				"/metrics",
-				http.HandlerFunc(
-					promhttp.Handler().ServeHTTP,
-				),
-			)
+			r.Get("/metrics", s.h.HandleMetrics())
 		})
 	}
 
@@ -147,10 +160,13 @@ func (s *Server) setupRoutes() {
 
 func (s *Server) setupPageRoutes() {
 	s.router.Route("/pages", func(r chi.Router) {
+		s.recoverPanics(
+			r, s.h.HandleErrorPage(http.StatusInternalServerError),
+		)
 		// MaxBodySize precedes CSRF and RequireAuth deliberately;
 		// see maxFormBodySize for why, and for what it costs.
 		r.Use(s.mw.MaxBodySize(maxFormBodySize))
-		r.Use(s.mw.CSRF())
+		r.Use(s.mw.CSRF(s.h.HandleErrorPage(http.StatusForbidden)))
 		r.Use(s.mw.NoCache())
 
 		// The login POST carries no pre-emptive rate limiter. Behind
@@ -169,10 +185,13 @@ func (s *Server) setupPageRoutes() {
 
 func (s *Server) setupUserRoutes() {
 	s.router.Route("/user/{username}", func(r chi.Router) {
+		s.recoverPanics(
+			r, s.h.HandleErrorPage(http.StatusInternalServerError),
+		)
 		// MaxBodySize precedes CSRF and RequireAuth deliberately;
 		// see maxFormBodySize for why, and for what it costs.
 		r.Use(s.mw.MaxBodySize(maxFormBodySize))
-		r.Use(s.mw.CSRF())
+		r.Use(s.mw.CSRF(s.h.HandleErrorPage(http.StatusForbidden)))
 		r.Use(s.mw.NoCache())
 		r.Use(s.mw.RequireAuth())
 		r.Get("/", s.h.HandleProfile())
@@ -184,10 +203,13 @@ func (s *Server) setupUserRoutes() {
 
 func (s *Server) setupSourceRoutes() {
 	s.router.Route("/hooks", func(r chi.Router) {
+		s.recoverPanics(
+			r, s.h.HandleErrorPage(http.StatusInternalServerError),
+		)
 		// MaxBodySize precedes CSRF and RequireAuth deliberately;
 		// see maxFormBodySize for why, and for what it costs.
 		r.Use(s.mw.MaxBodySize(maxFormBodySize))
-		r.Use(s.mw.CSRF())
+		r.Use(s.mw.CSRF(s.h.HandleErrorPage(http.StatusForbidden)))
 		r.Use(s.mw.NoCache())
 		r.Use(s.mw.RequireAuth())
 		r.Get("/", s.h.HandleSourceList())
@@ -196,10 +218,13 @@ func (s *Server) setupSourceRoutes() {
 	})
 
 	s.router.Route("/hook/{sourceID}", func(r chi.Router) {
+		s.recoverPanics(
+			r, s.h.HandleErrorPage(http.StatusInternalServerError),
+		)
 		// MaxBodySize precedes CSRF and RequireAuth deliberately;
 		// see maxFormBodySize for why, and for what it costs.
 		r.Use(s.mw.MaxBodySize(maxFormBodySize))
-		r.Use(s.mw.CSRF())
+		r.Use(s.mw.CSRF(s.h.HandleErrorPage(http.StatusForbidden)))
 		r.Use(s.mw.NoCache())
 		r.Use(s.mw.RequireAuth())
 		r.Get("/", s.h.HandleSourceDetail())

internal/server/routes_test.go

@@ -24,6 +24,7 @@ import (
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/healthcheck"
 	"sneak.berlin/go/webhooker/internal/logger"
+	"sneak.berlin/go/webhooker/internal/metrics"
 	"sneak.berlin/go/webhooker/internal/middleware"
 	"sneak.berlin/go/webhooker/internal/server"
 	"sneak.berlin/go/webhooker/internal/session"
@@ -46,12 +47,18 @@ type noopNotifier struct{}
 
 func (n *noopNotifier) Notify([]delivery.Task) {}
 
-// noopEvictor satisfies handlers.New's delivery.WebhookEvictor
-// dependency. No test here checks what gets evicted, so it records
-// nothing.
-type noopEvictor struct{}
+// noopArchives satisfies handlers.New's delivery.Archives
+// dependency. No test here checks what gets evicted or renamed, so
+// it records nothing.
+type noopArchives struct{}
 
-func (e *noopEvictor) EvictWebhook(string) {}
+func (e *noopArchives) EvictWebhook(string) {}
+
+func (e *noopArchives) EvictTarget(string) {}
+
+func (e *noopArchives) Rename(_, _, _ string) error {
+	return nil
+}
 
 // testEnv is the real router from routes.go plus the collaborators
 // tests need to seed users and forge sessions.
@@ -112,7 +119,9 @@ func newTestEnvWithConfig(
 			healthcheck.New,
 			session.New,
 			func() delivery.Notifier { return &noopNotifier{} },
-			func() delivery.WebhookEvictor { return &noopEvictor{} },
+			func() delivery.Archives { return &noopArchives{} },
+			metrics.NewRegistry,
+			metrics.New,
 			middleware.New,
 			delivery.NewGuard,
 			handlers.New,
@@ -260,6 +269,24 @@ func (e *testEnv) urlFrom(
 	return html.UnescapeString(match[1])
 }
 
+// requireNotice requires w to redirect to dest carrying the notice
+// code, then renders that page and requires it to show text.
+func (e *testEnv) requireNotice(
+	t *testing.T,
+	w *httptest.ResponseRecorder,
+	dest, code, text string,
+	cookies []*http.Cookie,
+) {
+	t.Helper()
+
+	require.Equal(t, http.StatusSeeOther, w.Code)
+	require.Equal(t, dest+"?notice="+code, w.Header().Get("Location"))
+
+	page := e.get(w.Header().Get("Location"), cookies)
+	require.Equal(t, http.StatusOK, page.Code)
+	assert.Contains(t, page.Body.String(), text)
+}
+
 // authCookies forges an authenticated session for the given user.
 func (e *testEnv) authCookies(
 	t *testing.T,
@@ -738,6 +765,31 @@ func TestPagesLogin_ReturnsToTheRequestedPage(t *testing.T) {
 	assert.Equal(t, asked, w.Header().Get("Location"))
 }
 
+// TestPagesLogout_SaysSignedOut signs out with the navbar's form and
+// lands on the sign-in page, which says so.
+func TestPagesLogout_SaysSignedOut(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	userID, _ := env.seedUser(t, "leaver", "somepassword")
+	token, cookies := env.csrfFrom(
+		t, "/hooks", env.authCookies(t, userID, "leaver"),
+	)
+
+	form := url.Values{}
+	form.Set("csrf_token", token)
+
+	w := env.post(
+		env.urlFrom(t, "/hooks", `action="(/pages/logout)"`, cookies),
+		form, cookies,
+	)
+
+	// The sign-in page is requested without the session cookie, which
+	// the logout told the browser to delete.
+	env.requireNotice(t, w, "/pages/login", "signed-out", "Signed out.", nil)
+}
+
 // --- /user/{username} group ---
 
 // TestPasswordChange_OversizeBody_RejectedAndPasswordUnchanged
@@ -855,9 +907,9 @@ func TestHooks_ListAndNewWebhookForm(t *testing.T) {
 	require.NoError(t,
 		env.db.DB().Where("name = ?", "created").First(&created).Error,
 	)
-	assert.Equal(
-		t, "/hook/"+created.ID, w.Header().Get("Location"),
-		"creating a webhook should redirect to its page",
+	env.requireNotice(
+		t, w, "/hook/"+created.ID, "webhook-created", "Webhook created.",
+		cookies,
 	)
 }
 
@@ -888,8 +940,7 @@ func TestHook_EditFormAndDelete(t *testing.T) {
 		env.urlFrom(t, editPage, `action="(/hook/[^/"]+/edit)"`, cookies),
 		form, cookies,
 	)
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(t, page, w.Header().Get("Location"))
+	env.requireNotice(t, w, page, "webhook-saved", "Webhook saved.", cookies)
 
 	var edited database.Webhook
 
@@ -903,16 +954,17 @@ func TestHook_EditFormAndDelete(t *testing.T) {
 		env.urlFrom(t, page, `action="(/hook/[^/"]+/delete)"`, cookies),
 		form, cookies,
 	)
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(t, "/hooks", w.Header().Get("Location"))
+	env.requireNotice(
+		t, w, "/hooks", "webhook-deleted", "Webhook deleted.", cookies,
+	)
 	assert.Equal(
 		t, http.StatusNotFound, env.get(page, cookies).Code,
 		"a deleted webhook's page should be gone",
 	)
 }
 
-// TestHook_EntrypointActions adds, deactivates and deletes an
-// entrypoint with the forms on the webhook page, each submitted to
+// TestHook_EntrypointActions adds, deactivates, activates and deletes
+// an entrypoint with the forms on the webhook page, each submitted to
 // the action and with the token the page rendered.
 func TestHook_EntrypointActions(t *testing.T) {
 	t.Parallel()
@@ -930,16 +982,19 @@ func TestHook_EntrypointActions(t *testing.T) {
 	form.Set("csrf_token", token)
 
 	// submit posts the webhook page's form whose action pattern
-	// captures, and requires the redirect back to that page.
-	submit := func(pattern string) {
+	// captures, and requires the redirect back to that page with the
+	// notice code, and the page to show text.
+	submit := func(pattern, code, text string) {
 		t.Helper()
 
 		w := env.post(env.urlFrom(t, page, pattern, cookies), form, cookies)
-		require.Equal(t, http.StatusSeeOther, w.Code)
-		require.Equal(t, page, w.Header().Get("Location"))
+		env.requireNotice(t, w, page, code, text, cookies)
 	}
 
-	submit(`action="(/hook/[^/"]+/entrypoints)"`)
+	toggle := `action="(/hook/[^/"]+/entrypoints/[^/"]+/toggle)"`
+
+	submit(`action="(/hook/[^/"]+/entrypoints)"`,
+		"entrypoint-added", "Entrypoint added.")
 
 	var added database.Entrypoint
 
@@ -948,7 +1003,7 @@ func TestHook_EntrypointActions(t *testing.T) {
 	)
 	require.True(t, added.Active)
 
-	submit(`action="(/hook/[^/"]+/entrypoints/[^/"]+/toggle)"`)
+	submit(toggle, "entrypoint-deactivated", "Entrypoint deactivated.")
 
 	var toggled database.Entrypoint
 
@@ -957,7 +1012,10 @@ func TestHook_EntrypointActions(t *testing.T) {
 	)
 	assert.False(t, toggled.Active, "the toggle should deactivate it")
 
-	submit(`action="(/hook/[^/"]+/entrypoints/[^/"]+/delete)"`)
+	submit(toggle, "entrypoint-activated", "Entrypoint activated.")
+
+	submit(`action="(/hook/[^/"]+/entrypoints/[^/"]+/delete)"`,
+		"entrypoint-deleted", "Entrypoint deleted.")
 
 	var left int64
 
@@ -968,8 +1026,8 @@ func TestHook_EntrypointActions(t *testing.T) {
 
 // TestHook_TargetActions adds a target with the form on the webhook
 // page, follows its Edit link to the target edit form and submits
-// it, then deactivates and deletes it, every URL and token taken from
-// the rendered pages.
+// it, then deactivates, activates and deletes it, every URL and token
+// taken from the rendered pages.
 func TestHook_TargetActions(t *testing.T) {
 	t.Parallel()
 
@@ -984,27 +1042,29 @@ func TestHook_TargetActions(t *testing.T) {
 
 	// submit posts form, with the token, to the action pattern
 	// captures on the page at from, and requires the redirect back to
-	// the webhook page.
-	submit := func(from, pattern string, form url.Values) {
+	// the webhook page with the notice code, and that page to show
+	// text.
+	submit := func(from, pattern string, form url.Values, code, text string) {
 		t.Helper()
 
 		form.Set("csrf_token", token)
 
 		w := env.post(env.urlFrom(t, from, pattern, cookies), form, cookies)
-		require.Equal(t, http.StatusSeeOther, w.Code)
-		require.Equal(t, page, w.Header().Get("Location"))
+		env.requireNotice(t, w, page, code, text, cookies)
 	}
 
+	toggle := `action="(/hook/[^/"]+/targets/[^/"]+/toggle)"`
+
 	submit(page, `action="(/hook/[^/"]+/targets)"`, url.Values{
 		"name": {"added"},
 		"type": {string(database.TargetTypeLog)},
-	})
+	}, "target-added", "Target added.")
 
 	editPage := env.urlFrom(
 		t, page, `href="(/hook/[^/"]+/targets/[^/"]+/edit)"`, cookies,
 	)
 	submit(editPage, `action="(/hook/[^/"]+/targets/[^/"]+/edit)"`,
-		url.Values{"name": {"renamed"}})
+		url.Values{"name": {"renamed"}}, "target-saved", "Target saved.")
 
 	var edited database.Target
 
@@ -1014,8 +1074,8 @@ func TestHook_TargetActions(t *testing.T) {
 	assert.Equal(t, "renamed", edited.Name)
 	require.True(t, edited.Active)
 
-	submit(page, `action="(/hook/[^/"]+/targets/[^/"]+/toggle)"`,
-		url.Values{})
+	submit(page, toggle, url.Values{},
+		"target-deactivated", "Target deactivated.")
 
 	var toggled database.Target
 
@@ -1024,8 +1084,11 @@ func TestHook_TargetActions(t *testing.T) {
 	)
 	assert.False(t, toggled.Active, "the toggle should deactivate it")
 
+	submit(page, toggle, url.Values{},
+		"target-activated", "Target activated.")
+
 	submit(page, `action="(/hook/[^/"]+/targets/[^/"]+/delete)"`,
-		url.Values{})
+		url.Values{}, "target-deleted", "Target deleted.")
 
 	var left int64
 
@@ -1061,9 +1124,9 @@ func TestHook_ResubmitFromEventLog(t *testing.T) {
 		env.urlFrom(t, logsPath, `action="(/hook/[^"]+/resubmit)"`, cookies),
 		form, cookies,
 	)
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, logsPath+"?resubmit=no-targets", w.Header().Get("Location"),
+	env.requireNotice(
+		t, w, logsPath, "resubmit-no-targets",
+		"this source has no active targets", cookies,
 	)
 
 	webhookDB, err := env.dbMgr.GetDB(wh.ID)
@@ -1299,10 +1362,8 @@ func TestDeliveryReplay_PostOnlyAndCSRFProtected(t *testing.T) {
 		html.UnescapeString(action[1]), form, cookies,
 	)
 
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, logsPath+"?replay=queued",
-		w.Header().Get("Location"),
+	env.requireNotice(
+		t, w, logsPath, "replay-queued", "Replay queued:", cookies,
 	)
 	assert.Equal(
 		t, int64(2), env.countDeliveries(t, wh.ID),
@@ -1478,3 +1539,46 @@ func TestMetricsRouteUnmountedOnHalfSetConfig(t *testing.T) {
 		})
 	}
 }
+
+// TestTwoMetricsRoutersInOneProcess pins
+// https://git.eeqj.de/sneak/webhooker/issues/227: a second
+// metrics-enabled router in one process used to panic, because the
+// HTTP metrics registered on Prometheus's global default registry.
+// Two routers are built over separate dependency graphs and a third
+// over the first graph again, and each must still serve the HTTP,
+// delivery, Go runtime and process series, and the series counting
+// scrapes of /metrics itself.
+func TestTwoMetricsRoutersInOneProcess(t *testing.T) {
+	t.Parallel()
+
+	first := newTestEnvWithConfig(
+		t, metricsConfig(t, metricsUser, metricsAuthValue),
+	)
+	second := newTestEnvWithConfig(
+		t, metricsConfig(t, metricsUser, metricsAuthValue),
+	)
+	third := &testEnv{
+		router: server.NewRouterForTest(
+			first.log.Get(), first.cfg, first.mw, first.hnd,
+		),
+	}
+
+	for _, env := range []*testEnv{first, second, third} {
+		env.get("/", nil)
+
+		scrape := env.metricsRequest(metricsUser, metricsAuthValue)
+		require.Equal(t, http.StatusOK, scrape.Code)
+
+		for _, series := range []string{
+			"http_request_duration_seconds",
+			"http_response_size_bytes",
+			"http_requests_inflight",
+			"webhooker_events_received_total",
+			"go_goroutines",
+			"process_start_time_seconds",
+			"promhttp_metric_handler_requests_total",
+		} {
+			assert.Contains(t, scrape.Body.String(), series)
+		}
+	}
+}

internal/versionscript/version_script_test.go

@@ -115,8 +115,8 @@ func TestVersion_EnclosingRepositoryIsNotUsed(t *testing.T) {
 	require.Equal(t, unknown, runScript(t, inner, nil))
 }
 
-// The Docker build has no git metadata, so the version arrives as an
-// environment override. It wins over anything derivable.
+// An explicit VERSION, such as the Dockerfile's build arg, wins over
+// anything derivable.
 func TestVersion_EnvironmentOverrideWins(t *testing.T) {
 	t.Parallel()
 
@@ -128,8 +128,8 @@ func TestVersion_EnvironmentOverrideWins(t *testing.T) {
 }
 
 // An empty VERSION is treated as unset rather than stamping an empty
-// string: the Dockerfile's build arg has a non-empty default, but a
-// caller exporting VERSION= must not produce a binary reporting "".
+// string: a caller exporting VERSION= must not produce a binary
+// reporting "".
 func TestVersion_EmptyOverrideFallsBackToGit(t *testing.T) {
 	t.Parallel()
 
@@ -168,8 +168,8 @@ func TestMakefile_BuildComposesVersionAndExtraFlags(t *testing.T) {
 }
 
 // A caller can define VERSION as the empty string -- `make build
-// VERSION=`, or a `--build-arg VERSION=` reaching the Dockerfile's `make
-// build VERSION="$VERSION"`. script/version's own guard does not cover
+// VERSION=`, or the Dockerfile's `make build VERSION="$VERSION"` when no
+// VERSION build arg was given. script/version's own guard does not cover
 // that: the value never passes through the script. Stamping "" would
 // leave the binary reporting no version and the footer on "dev", which
 // is the defect this package exists for.
@@ -231,7 +231,7 @@ func TestDockerfile_BuildsThroughTheMakeTarget(t *testing.T) {
 
 	require.NotContains(t, dockerfile, "go build",
 		"a raw go build bypasses the Makefile's -X flag")
-	require.Contains(t, dockerfile, "ARG VERSION=")
+	require.Contains(t, dockerfile, "ARG VERSION")
 	require.Contains(t, dockerfile,
 		`make build VERSION="$VERSION" GO_LDFLAGS='-extldflags "-static"'`)
 }

script/docker

@@ -2,9 +2,9 @@
 # script/docker: build the Docker image tagged with the project name.
 # The tag comes from script/projectname.
 #
-# .dockerignore excludes .git/, so the builder stage cannot derive the
-# version itself. It is resolved here, where the checkout is, and passed
-# in as a build arg; without it the image would stamp itself "unknown".
+# The version script/version resolves here goes in as the VERSION build
+# arg, which takes precedence over what the build would derive from the
+# .git in its context.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"

script/version

@@ -7,18 +7,16 @@
 #
 # Order of precedence:
 #
-#   1. $VERSION, if set and non-empty. This is how the value reaches a
-#      build that cannot derive it: .dockerignore excludes .git/, so the
-#      builder stage has no git metadata and the Dockerfile takes the
-#      value as a build arg instead.
+#   1. $VERSION, if set and non-empty: an explicit value, such as the
+#      Dockerfile's VERSION build arg.
 #   2. `git describe --tags --always --dirty` against this checkout. At
 #      a clean tagged commit that is exactly the tag; otherwise it
 #      carries the short SHA, the commit distance when a tag is
 #      reachable, and a -dirty suffix for uncommitted changes.
 #   3. "unknown", for a tree with no git metadata and no $VERSION -- a
-#      source tarball, or `docker build .` with no --build-arg. That
-#      case must not fail the build and must not name a tag the tree may
-#      not be at, so it names nothing.
+#      source tarball, or a `docker build` with no .git in its context
+#      and no VERSION build arg. That case must not fail the build and
+#      must not name a tag the tree may not be at, so it names nothing.
 #
 # The git step insists the enclosing repository is this checkout, not
 # merely some repository above it: an unpacked tarball sitting inside an

templates/base.html

@@ -7,6 +7,7 @@
 <body class="bg-gray-50 min-h-screen flex flex-col">
     <div class="flex-grow">
         {{template "navbar" .}}
+        {{template "notice" .}}
         {{block "content" .}}{{end}}
     </div>
     {{template "footer" .}}

templates/error.html

@@ -0,0 +1,15 @@
+{{template "base" .}}
+
+{{define "title"}}{{.StatusText}} - Webhooker{{end}}
+
+{{define "content"}}
+<div class="max-w-4xl mx-auto px-6 py-12">
+    <h1 class="text-2xl font-medium text-gray-900 mb-4">{{.Status}} {{.StatusText}}</h1>
+    <p class="text-gray-600 mb-6">{{.Message}}</p>
+    {{if .User}}
+    <a href="/hooks" class="btn-secondary">Back to webhooks</a>
+    {{else}}
+    <a href="/pages/login" class="btn-primary">Sign in</a>
+    {{end}}
+</div>
+{{end}}

templates/navbar.html

@@ -26,11 +26,15 @@
                 </svg>
                 {{.User.Username}}
             </a>
+            {{/* An error page can be served before a form token is issued,
+                 and a logout without one is refused. */}}
+            {{if .CSRFToken}}
             <form method="POST" action="/pages/logout" class="inline">
                 <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
                 <button type="submit" class="btn-text">Logout</button>
             </form>
             {{end}}
+            {{end}}
         </div>
     </div>
 
@@ -40,11 +44,13 @@
             {{if .User}}
             <a href="/hooks" class="btn-text w-full text-left">Webhooks</a>
             <a href="/user/{{.User.Username}}" class="btn-text w-full text-left">Profile</a>
+            {{if .CSRFToken}}
             <form method="POST" action="/pages/logout">
                 <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
                 <button type="submit" class="btn-text w-full text-left">Logout</button>
             </form>
             {{end}}
+            {{end}}
         </div>
     </div>
 </nav>

templates/notice.html

@@ -0,0 +1,7 @@
+{{define "notice"}}
+{{with .Notice}}
+<div class="max-w-6xl mx-auto px-6 pt-4">
+    <div class="{{if .Failed}}alert-error{{else}}alert-success{{end}}">{{.Text}}</div>
+</div>
+{{end}}
+{{end}}

templates/source_detail.html

@@ -3,10 +3,14 @@
 {{define "title"}}{{.Webhook.Name}} - Webhooker{{end}}
 
 {{define "content"}}
-<div class="max-w-6xl mx-auto px-6 py-8" x-data="{ showAddEntrypoint: false, showAddTarget: false }">
+<!-- 108rem, half again the 72rem (max-w-6xl) of the webhook list, the
+     event log, the navbar and the footer, so an entrypoint URL fits on
+     one line. An inline style, because the committed tailwind.css has
+     no class this wide. -->
+<div class="mx-auto px-6 py-8" style="max-width: 108rem" x-data="{ showAddEntrypoint: false, showAddTarget: false }">
     <div class="mb-6">
         <a href="/hooks" class="text-sm text-primary-600 hover:text-primary-700">&larr; Back to webhooks</a>
-        <div class="flex justify-between items-center mt-2">
+        <div class="flex flex-wrap justify-between items-center gap-2 mt-2">
             <div>
                 <h1 class="text-2xl font-medium text-gray-900">{{.Webhook.Name}}</h1>
                 {{if .Webhook.Description}}

templates/source_logs.html

@@ -12,14 +12,6 @@
         </div>
     </div>
 
-    {{if .ReplayMessage}}
-    <div class="{{if .ReplayQueued}}alert-success{{else}}alert-error{{end}}">{{.ReplayMessage}}</div>
-    {{end}}
-
-    {{if .ResubmitMessage}}
-    <div class="{{if .ResubmitQueued}}alert-success{{else}}alert-error{{end}}">{{.ResubmitMessage}}</div>
-    {{end}}
-
     <div class="card">
         <div class="divide-y divide-gray-100">
             {{range .Events}}