deploy (#365)

Reviewed-on: #365

Dockerfile

@@ -88,7 +88,9 @@ RUN CGO_ENABLED=1 make build VERSION="$VERSION" GO_LDFLAGS='-extldflags "-static
 # alpine:3.21, 2026-03-17
 FROM alpine:3.21@sha256:c3f8e73fdb79deaebaa2037150150191b9dcbfba68b4a46d70103204c53f4709
 
-RUN apk --no-cache add ca-certificates
+# su-exec 0.2-r3 (Alpine 3.21), 2026-09-29: the entrypoint runs the app
+# as webhooker with it.
+RUN apk --no-cache add ca-certificates su-exec=0.2-r3
 
 # Create non-root user
 RUN addgroup -g 1000 -S webhooker && \
@@ -99,13 +101,17 @@ WORKDIR /app
 # Copy binary from builder
 COPY --from=builder /build/bin/webhooker /app/webhooker
 
+# Not under /app, which belongs to webhooker: this script runs as root.
+COPY deploy/docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
+
 # Create data directory for all SQLite databases (main app DB +
 # per-webhook event DBs). DATA_DIR defaults to /var/lib/webhooker.
 RUN mkdir -p /var/lib/webhooker
 
 RUN chown -R webhooker:webhooker /app /var/lib/webhooker
 
-USER webhooker
+# No USER: the entrypoint starts as root to make the data directory
+# webhooker's, then runs the app as webhooker.
 
 EXPOSE 8080
 
@@ -124,4 +130,5 @@ ENV BIND_ADDRESS=0.0.0.0
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
     CMD wget --no-verbose --tries=1 --spider http://localhost:8080/.well-known/healthcheck || exit 1
 
+ENTRYPOINT ["/usr/local/bin/docker-entrypoint.sh"]
 CMD ["/app/webhooker"]

README.md

@@ -157,6 +157,11 @@ private and reserved ranges — RFC 1918, loopback, CGNAT, link-local and
 the rest — are refused, which stops a target from being used to make
 webhooker probe the network it sits in.
 
+Besides the private and reserved ranges, the default blocklist refuses
+public cloud metadata addresses: currently only `168.63.129.16`, Azure's
+WireServer, which serves an Azure VM its credentials. Because it is a
+public address, listing it in `ALLOWED_EGRESS_CIDRS` reopens it.
+
 That default is also inconvenient for the thing webhooker is mostly
 for: taking a public webhook and forwarding it to something on your own
 network. A container on the same Docker network, a box on `10.x`, a
@@ -195,15 +200,16 @@ Two things this setting cannot do:
   the list is always an allowlist; an empty list (the default) means
   every private and reserved range stays refused. Note that
   `0.0.0.0/0` gets you most of the way there anyway, per above.
-- **It cannot open link-local, or a cloud metadata endpoint that
-  discloses credentials or user data.** An address is on the list below
-  when both of these hold: the provider fixes it, so it cannot collide
-  with anything you run; and reaching it hands out credentials, user
-  data or bootstrap material. Those stay blocked no matter what you
-  list, including when you list them outright or list a supernet such
-  as `0.0.0.0/0`, `::/0`, `fd00::/8` or `100.64.0.0/10`. Treat this as
-  best effort rather than a guarantee — it is a hand-maintained list
-  and the caveat below the table applies:
+- **It cannot open link-local, or a cloud metadata endpoint at a
+  non-public address that discloses credentials or user data.** An
+  address is on the list below when it is not a public address and both
+  of these hold: the provider fixes it, so it cannot collide with
+  anything you run; and reaching it hands out credentials, user data or
+  bootstrap material. Those stay blocked no matter what you list,
+  including when you list them outright or list a supernet such as
+  `0.0.0.0/0`, `::/0`, `fd00::/8` or `100.64.0.0/10`. Treat this as best
+  effort rather than a guarantee — it is a hand-maintained list and the
+  caveat below the table applies:
 
   | Blocked unconditionally | What it is |
   | ----------------------- | ---------- |
@@ -242,7 +248,8 @@ Two things this setting cannot do:
   encodings, which the default blocklist does not match. A publicly
   routable metadata address is not listed here, because nothing on this
   list can be reopened and blocking one that way would leave you no
-  escape hatch at all.
+  escape hatch at all; Azure's `168.63.129.16` is refused by the default
+  blocklist instead, as described above.
 
   This list is not exhaustive of every cloud's metadata address — if
   yours is not here, do not allowlist the block that contains it.
@@ -531,6 +538,12 @@ its Argon2id hash. There is no second account and no forgot-password
 flow, so the banner and the reset command below are the only two ways
 in.
 
+A start that finds no `webhooker.db` in `DATA_DIR` also logs
+`created a new, empty database` at `WARN`, with the file's path,
+shortly before the banner. On a deployment that has run before, that
+line means `DATA_DIR` was empty, most often because its volume is not
+mounted.
+
 #### Recovering a lost admin password
 
 `webhooker resetpw` sets an existing account's password from the
@@ -545,8 +558,9 @@ printf '%s' "$NEW_PASSWORD" | \
     DATA_DIR=/var/lib/webhooker webhooker resetpw admin
 ```
 
-In a container it is the same binary, which the image sets as `CMD`
-rather than `ENTRYPOINT`, so the whole command has to be given:
+In a container it is the same binary. The image's `CMD` is
+`/app/webhooker`, and a command given to `docker run` replaces all of
+it, so the whole command has to be given:
 
 ```bash
 docker run --rm -v webhooker-data:/var/lib/webhooker \
@@ -683,38 +697,22 @@ those three values rather than trusting the figure. Measured at 65s on
 Docker 29.7.2.) A container `unhealthy` with `connection refused` in
 its health log, or a published port that resets connections, is this.
 
-The container runs as a non-root user (`webhooker`, UID 1000), exposes
-port 8080, and includes a health check against
-`/.well-known/healthcheck`. 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 preserve data across container
-restarts.
+The app runs as a non-root user (`webhooker`, UID 1000), exposes port
+8080, and includes a health check against `/.well-known/healthcheck`.
+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
+preserve data across container restarts.
 
-**The bind-mounted directory must be owned by UID 1000, or the
-container does not start.** Docker creates a `-v` source path that
-does not exist yet as `root:root`, and the process runs as UID 1000,
-so it cannot take its `DATA_DIR` lock:
-
-```
-webhooker: locking data directory /var/lib/webhooker: open
-/var/lib/webhooker/webhooker.lock: permission denied
-```
-
-It exits non-zero at that point, before opening any database. Create
-the directory ahead of the first `docker run`:
-
-```bash
-mkdir -p /path/to/data
-chown 1000:1000 /path/to/data
-chmod 750 /path/to/data
-```
-
-The same `chown` is what a restore needs — see step 4 of
-[Restore](#restore). A **named volume** does not have this problem:
-Docker copies the image's ownership onto a volume it initializes, and
-the image creates `/var/lib/webhooker` owned by `webhooker`.
+**The container sets its data directory's owner and mode itself
+before the app starts**, so a host directory can be mounted as it is,
+whoever owns it. The image's `ENTRYPOINT`,
+`deploy/docker-entrypoint.sh`, starts as root, creates `DATA_DIR` if
+it is missing, gives the directory and anything in it that belongs to
+another user to `webhooker`, sets the directory to `0750`, and only
+then runs the app as `webhooker`. Started with `--user`, it changes
+nothing and runs the app as that user.
 
 **The file modes are not yours to set, and do not depend on the
 directory.** `webhooker.db` holds target configuration in plaintext —
@@ -722,13 +720,10 @@ bearer tokens, API keys, Slack webhook URLs — along with the session
 encryption key, so webhooker creates every SQLite file it owns `0600`:
 each database and both of its `-wal` and `-shm` sidecars, across all
 three tiers. Files an earlier build left `0644` are tightened when
-they are opened. A `DATA_DIR` webhooker creates itself is `0750`, but
-a bind mount supplies its own directory and Docker's default for one
-it creates is `0755`; the `0600` files hold there regardless. The
-`chmod 750` above is defence in depth — it stops other local users
-listing the directory and learning your webhook UUIDs from the
-`events-{uuid}.db` filenames — not the barrier protecting the
-credentials.
+they are opened. The directory's `0750` is defence in depth — it stops
+other local users listing the directory and learning your webhook
+UUIDs from the `events-{uuid}.db` filenames — not the barrier
+protecting the credentials.
 
 ### Running under upaas
 
@@ -744,17 +739,6 @@ repository's `Dockerfile` and runs it. The app needs:
   app name, port `8080`. Leave `PORT` unset: the image's health check
   probes `8080`.
 - **Volume:** one host directory mounted at `/var/lib/webhooker`.
-  upaas bind-mounts the host path it is given and does not create it,
-  and the container does not start unless UID 1000 owns it (see
-  [Running with Docker](#running-with-docker)). Create it before the
-  first deploy:
-
-    ```bash
-    mkdir -p /path/to/data
-    chown 1000:1000 /path/to/data
-    chmod 750 /path/to/data
-    ```
-
 - **Environment variables:**
     - `WEBHOOKER_ENVIRONMENT=prod`
     - `TRUSTED_PROXIES`: your reverse proxy's address on that Docker
@@ -968,15 +952,10 @@ scratch file**: it holds committed transactions that are not yet in the
 have no readable schema at all. `-shm` is regenerable, but there is no
 reason to separate the two — copy the directory and you have them.
 
-A clean shutdown closes `webhooker.db` and every `events-*.db`, which
-checkpoints and removes their sidecars; a killed or crashed instance
-leaves them, and they must be carried with the `.db`. **Archive
-databases are different**: their handle is not closed at shutdown, so
-`archive-*.db-wal` and `-shm` normally survive a clean stop and the
-`-wal` can hold every row the archive has. Measured on a stopped
-instance: `archive-….db` 4096 bytes with no table, its `-wal` 157 KB
-holding all 8 archived events. Copying `DATA_DIR` in full is what makes
-this a non-issue; copying `.db` files out of it by name is not.
+A clean shutdown closes every database, which checkpoints and removes
+its sidecars; a killed or crashed instance leaves them, and they must be
+carried with the `.db`. An archive the service has not opened since a
+crash keeps that crash's sidecars, even across a later clean stop.
 
 Configuration is **not** in `DATA_DIR` — it comes from the environment
 and from a `.env` file read out of the process working directory. Back
@@ -1018,12 +997,12 @@ done
 `.backup` reads through the WAL and writes a single consistent file with
 no sidecars of its own, so the destination is complete as it stands.
 Two caveats. First, the runtime image is `alpine:3.21` with only
-`ca-certificates` added — the `sqlite3` CLI is **not** in it, so run
-this on the host against the volume path, or from a throwaway container
-that mounts the volume. Second, each file is captured at its own
-instant, so a webhook created or an event delivered between two files
-being copied lands in one and not the other. If you need the whole set
-coherent as of a single moment, stop the service.
+`ca-certificates` and `su-exec` added — the `sqlite3` CLI is **not** in
+it, so run this on the host against the volume path, or from a
+throwaway container that mounts the volume. Second, each file is
+captured at its own instant, so a webhook created or an event delivered
+between two files being copied lands in one and not the other. If you
+need the whole set coherent as of a single moment, stop the service.
 
 Note that `sqlite3 <db> .dump` is **not** one of these procedures: it is
 an export, it holds a read transaction open for as long as it runs, and
@@ -1051,10 +1030,9 @@ The file becomes self-contained again when the handle closes, which
 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.
-Shutdown is **not** on that list: the archive handle is not closed when
-the service stops. So either move `archive-{uuid}.db` together with any
-`-wal`/`-shm` beside it, or wait until there are none.
+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
+with any `-wal`/`-shm` beside it, or wait until there are none.
 
 ### Restore
 
@@ -1073,28 +1051,16 @@ the service stops. So either move `archive-{uuid}.db` together with any
    They are part of the database, and dropping a `-wal` silently
    discards every transaction it still holds. An `.backup` set will not
    contain any: it writes a single consolidated file per database. A
-   stop-and-copy set has none for `webhooker.db` or the `events-*.db`,
-   because a clean stop closes those and checkpoints their sidecars
-   away — but it will normally have them for `archive-*.db`, whose
-   handle stays open across shutdown, and those carry the archive's
-   rows. A copy salvaged from a crashed instance has them for
-   everything, and needs all of them.
+   stop-and-copy set normally has none, because a clean stop closes
+   every database and checkpoints its sidecars away; the exception is an
+   archive not opened since a crash. A copy salvaged from a crashed
+   instance has them for everything, and needs all of them.
 
-4. **Fix ownership.** The container runs as the non-root `webhooker`
-   user, UID 1000 / GID 1000. Restored files must be owned by (or
-   writable by) that UID, and so must the directory itself — SQLite
-   creates the `-wal` and `-shm` sidecars beside the database, so a
-   writable file inside a directory it cannot write is not enough:
-
-    ```bash
-    chown -R 1000:1000 /path/to/data
-    ```
-
-    Restoring as `root` on the host and forgetting this step is the
-    usual way a restore fails.
-
-5. Start the service. `AutoMigrate` runs against each restored database
-   as it is opened.
+4. Start the service. The container gives the directory and the
+   restored files to the `webhooker` user before the app starts,
+   whoever restored them (see
+   [Running with Docker](#running-with-docker)). `AutoMigrate` runs
+   against each restored database as it is opened.
 
 ### Upgrades
 
@@ -2722,7 +2688,7 @@ abuse limit later; they are tracked as future work.
 | ------ | --------------------------- | ----------- |
 | `GET`  | `/`                         | Root redirect, 303 (authenticated → `/sources`, unauthenticated → `/pages/login`) |
 | `GET`  | `/.well-known/healthcheck`  | Health check (JSON: `status`, `now`, `uptimeSeconds`, `uptimeHuman`, `version`, `appname`, `maintenanceMode`) |
-| any    | `/s/*`                      | Static file serving (embedded CSS, JS). Mounted for every method, not just `GET`/`HEAD`: chi's `Mount` registers all methods and `http.FileServer` special-cases only `HEAD` (by omitting the body), so a `POST` or `DELETE` to an asset is answered `200` with the file. Pinned by `TestStaticServesEveryMethod` |
+| `GET`, `HEAD` | `/s/*`              | Static file serving (embedded CSS, JS). `GET` and `HEAD` only — `POST`, `PUT`, `PATCH`, `DELETE`, `OPTIONS`, `TRACE` and `CONNECT` are answered `405 Method Not Allowed` with `Allow: GET, HEAD`. Any other method (such as `PROPFIND`) is refused by chi before it reaches this route, and gets `405` without an `Allow` header. Pinned by `TestStaticServesOnlyGetAndHead` |
 | `POST` | `/webhook/{uuid}`           | Webhook receiver endpoint. `POST` only — every other method is answered `405 Method Not Allowed` with `Allow: POST`. Rate limited (see [Rate Limiting](#rate-limiting)) |
 
 #### Authentication Endpoints
@@ -3072,7 +3038,11 @@ check, see [The login endpoint](#the-login-endpoint).
 - Prometheus metrics behind basic auth
 - Static assets embedded in binary (no filesystem access needed at
   runtime)
-- Container runs as non-root user (UID 1000)
+- The app runs as the non-root `webhooker` user (UID 1000) in the
+  container. The image sets no `USER`, so these run as root: the
+  `ENTRYPOINT` script, which sets the data directory's owner and mode
+  before the app starts; the image's health check; and `docker exec`,
+  unless given `--user`
 - GORM soft deletes on every entity that carries `BaseModel`, which is
   all of them but `Setting` (data preserved for audit)
 
@@ -3088,7 +3058,8 @@ each hook. The order, read off the fx stop-hook log:
 3. `server` — the HTTP drain, bounded separately by
    `server.ShutdownTimeout` (**3 seconds**), then a Sentry flush if
    `SENTRY_DSN` is set
-4. `delivery.Engine`
+4. `delivery.Engine` — waits for its workers, then closes the archive
+   databases
 5. `healthcheck`
 6. `WebhookDBManager`
 7. the database close
@@ -3198,10 +3169,13 @@ version is fixed independently of the compiler's:
    `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 [Version stamping](#version-stamping)).
-3. **Runtime stage** (`alpine:3.21`) — copies the static binary,
-   creates the `/var/lib/webhooker` directory for all SQLite databases,
-   runs as the non-root `webhooker` user (UID 1000), exposes port 8080,
-   and includes a health check against `/.well-known/healthcheck`.
+3. **Runtime stage** (`alpine:3.21`) — copies the static binary and
+   `deploy/docker-entrypoint.sh`, creates the `/var/lib/webhooker`
+   directory for all SQLite databases, exposes port 8080, and includes
+   a health check against `/.well-known/healthcheck`. It sets no
+   `USER`: the `ENTRYPOINT` script starts as root, sets the data
+   directory's owner and mode, and runs the app as the non-root
+   `webhooker` user (UID 1000) through `su-exec`.
 
 The lint stage invokes `golangci-lint` directly rather than `make lint`:
 it is already the pinned linter image, and `make lint` builds
@@ -3280,3 +3254,5 @@ MIT
 ## Author
 
 [@sneak](https://sneak.berlin)
+
+

deploy/docker-entrypoint.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+# deploy/docker-entrypoint.sh: the image's ENTRYPOINT. A bind-mounted
+# data directory keeps its owner from the host, often root, and the app
+# could not write to it. Started as root, this creates DATA_DIR if
+# needed, gives it and everything in it to webhooker, sets its mode, and
+# runs the command as webhooker, so the app never runs as root. Started
+# as another user, it only runs the command.
+set -eu
+
+main() {
+    if [ "$(id -u)" != 0 ]; then
+        exec "$@"
+    fi
+
+    dir="${DATA_DIR:-/var/lib/webhooker}"
+    mkdir -p "$dir"
+    find "$dir" ! -user webhooker -exec chown -h webhooker:webhooker {} +
+    chmod 750 "$dir"
+    exec su-exec webhooker "$@"
+}
+
+main "$@"

internal/config/config.go

@@ -192,9 +192,10 @@ type Config struct {
 	// alwaysBlockedNetworks stays blocked no matter what is listed
 	// here. That set is link-local plus the cloud metadata
 	// endpoints outside it that disclose credentials or user data
-	// at a provider-fixed address; it is not exhaustive of every
-	// cloud's metadata address. See alwaysBlockedNetworks for the
-	// authoritative list and the criterion it is built from.
+	// at a provider-fixed, non-public address; it is not
+	// exhaustive of every cloud's metadata address. See
+	// alwaysBlockedNetworks for the authoritative list and the
+	// criterion it is built from.
 	AllowedEgressCIDRs []netip.Prefix
 
 	params *ConfigParams
@@ -746,12 +747,14 @@ func (c *Config) warnEgressAllowlist(log *slog.Logger) {
 
 	log.Warn(
 		"ALLOWED_EGRESS_CIDRS lets delivery targets reach these "+
-			"otherwise-blocked private/reserved networks. Anyone "+
-			"who can create a delivery target can now make this "+
-			"process issue requests into them, and read back the "+
-			"response. Link-local and the known cloud instance "+
-			"metadata endpoints outside it stay blocked "+
-			"regardless of what is listed here.",
+			"otherwise-blocked networks. Anyone who can create a "+
+			"delivery target can now make this process issue "+
+			"requests into them, and read back the response. Only "+
+			"the addresses the README lists as blocked "+
+			"unconditionally stay blocked regardless of what is "+
+			"listed here; a public cloud metadata address such as "+
+			"168.63.129.16 is reachable once it, or a block "+
+			"covering it, is listed.",
 		"allowedEgressCIDRs",
 		strings.Join(PrefixStrings(c.AllowedEgressCIDRs), ","),
 	)

internal/config/config_test.go

@@ -834,12 +834,13 @@ func TestEgressAllowlistWarning(t *testing.T) {
 			// to be able to read back which networks are open.
 			assert.Contains(t, logged, "10.0.0.0/8")
 			assert.Contains(t, logged, "127.0.0.0/8")
-			// What stays shut. Asserted on the clause naming the
-			// wider set rather than on "Link-local" alone, so the
-			// string cannot narrow back to link-local only while
-			// the always-blocked set covers ULA, CGNAT and two
-			// public metadata addresses as well.
-			assert.Contains(t, logged, "metadata endpoints outside it")
+			// What stays shut is the whole unconditional set, not
+			// link-local alone; a public metadata address is not in
+			// it, so a listed block covering it opens it.
+			assert.Contains(t, logged, "blocked unconditionally")
+			assert.Contains(t, logged, "168.63.129.16 is reachable")
+			// The listed blocks need not be private or reserved.
+			assert.NotContains(t, logged, "private/reserved")
 		})
 	}
 }

internal/database/bootstrap_banner_test.go

@@ -3,6 +3,8 @@ package database_test
 import (
 	"bytes"
 	"context"
+	"log/slog"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -83,3 +85,37 @@ func TestFirstBoot_PrintsTheAdminPasswordAsABanner(t *testing.T) {
 		t, ok, "the printed password must open the seeded account",
 	)
 }
+
+// TestNewDatabase_IsLoggedWithItsPath is the log half of
+// https://git.eeqj.de/sneak/webhooker/issues/359. A DATA_DIR that is
+// unexpectedly empty boots exactly like a first start, so the start
+// that creates the database must say so, and where. Opening that
+// database again must not.
+func TestNewDatabase_IsLoggedWithItsPath(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+
+	open := func() string {
+		var out bytes.Buffer
+
+		db, err := database.Open(dir, slog.New(slog.NewTextHandler(&out, nil)))
+		require.NoError(t, err)
+		require.NoError(t, db.Close())
+
+		return out.String()
+	}
+
+	const created = `level=WARN msg="created a new, empty database"`
+
+	first := open()
+	second := open()
+
+	assert.Contains(
+		t, first,
+		created+" path="+filepath.Join(dir, database.MainDBFileName),
+	)
+	assert.NotContains(
+		t, second, created, "an existing database is not new",
+	)
+}

internal/database/database.go

@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"io/fs"
 	"log/slog"
 	"os"
 	"path/filepath"
@@ -199,6 +200,12 @@ func (d *Database) connectTo(dataDir string) error {
 	// Construct the main application database path inside DATA_DIR.
 	dbPath := filepath.Join(dataDir, MainDBFileName)
 
+	// Checked before opening, which creates the file. A DATA_DIR that
+	// is unexpectedly empty -- its volume not mounted, say -- looks
+	// exactly like a first start, so a new database is a warning.
+	_, statErr := os.Stat(dbPath)
+	created := errors.Is(statErr, fs.ErrNotExist)
+
 	// Opened through OpenSQLite so this handle carries the same WAL
 	// journaling, busy timeout, immediate-transaction locking, and pool
 	// bounds as every other database file. See sqlite_open.go.
@@ -229,7 +236,12 @@ func (d *Database) connectTo(dataDir string) error {
 	}
 
 	d.db = db
+
+	if created {
+		d.log.Warn("created a new, empty database", "path", dbPath)
+	} else {
 		d.log.Info("connected to database", "path", dbPath)
+	}
 
 	// Run migrations
 	return d.migrate()

internal/delivery/engine.go

@@ -362,6 +362,15 @@ func (e *Engine) start() {
 // stop cancels the worker pool's context and waits for the pool
 // to drain, bounded by the stop hook's context: a wedged worker
 // must not hang the process past fx's stop timeout.
+//
+// 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
+// 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
+// nothing closes, so it gains nothing over a kill.
 func (e *Engine) stop(ctx context.Context) error {
 	e.log.Info("delivery engine stopping")
 
@@ -376,6 +385,8 @@ func (e *Engine) stop(ctx context.Context) error {
 		return err
 	}
 
+	e.dbTarget.evictAll()
+
 	e.log.Info("delivery engine stopped")
 
 	return nil
@@ -728,9 +739,7 @@ func (e *Engine) recoverSingleRetry(
 		// webhook on one bad read would be a far larger fault than
 		// the strand it is meant to clear.
 		if errors.Is(err, gorm.ErrRecordNotFound) {
-			e.failMissingTargetRetry(
-				webhookDB, webhookID, d,
-			)
+			e.failMissingTarget(webhookDB, webhookID, d)
 
 			return
 		}
@@ -1133,9 +1142,7 @@ func (e *Engine) sweepSingleRetry(
 		// Deleted is terminal, unreadable is not; see
 		// recoverSingleRetry.
 		if errors.Is(err, gorm.ErrRecordNotFound) {
-			e.failMissingTargetRetry(
-				webhookDB, webhookID, d,
-			)
+			e.failMissingTarget(webhookDB, webhookID, d)
 
 			return
 		}
@@ -1249,19 +1256,19 @@ func (e *Engine) failUnretryableRetry(
 	e.failDelivery(webhookDB, d, target.Type, reason)
 }
 
-// failMissingTargetRetry terminally fails an orphaned retrying
-// delivery whose target row is gone. Both restart recovery and the
-// periodic sweep call it, so the transition exists once.
+// failMissingTarget terminally fails a recovered delivery, pending or
+// retrying, whose target row is gone. Restart recovery and the periodic
+// sweep call it for both statuses, so the transition exists once.
 //
-// Until it existed both paths logged the failed lookup and returned,
-// which left the delivery retrying for the life of the database and
+// Until it existed those paths logged the failed lookup and moved on,
+// which left the delivery where it was for the life of the database and
 // the sweep repeating the same error every minute forever. Failing it
 // with a recorded reason is the treatment the other orphaned-retry
 // cases already get, so all of them read alike in the event log.
 //
 // Logged at warn rather than error: a deleted target is an operator
 // action, not a system fault.
-func (e *Engine) failMissingTargetRetry(
+func (e *Engine) failMissingTarget(
 	webhookDB *gorm.DB,
 	webhookID string,
 	d *database.Delivery,
@@ -1274,13 +1281,37 @@ func (e *Engine) failMissingTargetRetry(
 
 	defer e.inflight.release(d.ID)
 
+	// The batch was read before ownership was taken, and a worker may
+	// have settled the delivery and let it go in between. Only a row
+	// still in the status the batch read is failed.
+	row, err := e.loadDelivery(webhookDB, d.ID)
+	if err != nil {
+		e.log.Error(
+			"failed to load delivery",
+			"delivery_id", d.ID,
+			"error", err,
+		)
+
+		return
+	}
+
+	if row.Status != d.Status {
+		e.log.Debug(
+			"delivery already handled, not failed",
+			"delivery_id", d.ID,
+			"status", row.Status,
+		)
+
+		return
+	}
+
 	targetType, reason := e.missingTargetReason(d.TargetID)
 
 	e.log.Warn(
-		"failing orphaned retrying delivery: "+
-			"its target no longer exists",
+		"failing recovered delivery: its target no longer exists",
 		"webhook_id", webhookID,
 		"delivery_id", d.ID,
+		"status", d.Status,
 		"target_id", d.TargetID,
 		"target_type", targetType,
 	)
@@ -1314,15 +1345,14 @@ func (e *Engine) missingTargetReason(
 	if err != nil {
 		return "", fmt.Sprintf(
 			"target %s no longer exists; the delivery "+
-				"cannot be retried and has been failed "+
-				"terminally",
+				"has been failed terminally",
 			targetID,
 		)
 	}
 
 	return target.Type, fmt.Sprintf(
 		"target %q (type %s) was deleted; the delivery "+
-			"cannot be retried and has been failed terminally",
+			"has been failed terminally",
 		target.Name, target.Type,
 	)
 }
@@ -2021,14 +2051,31 @@ func (e *Engine) sendRecoveredDeliveries(
 
 		target, ok := targetMap[deliveries[i].TargetID]
 		if !ok {
+			// A missing entry does not mean the target is gone: the
+			// map is also empty when its query failed. Only a lookup
+			// that finds no row ends the delivery; any other error
+			// leaves it pending for the next sweep. See
+			// recoverSingleRetry.
+			var err error
+
+			target, err = e.loadTarget(deliveries[i].TargetID)
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				e.failMissingTarget(webhookDB, webhookID, &deliveries[i])
+
+				continue
+			}
+
+			if err != nil {
 				e.log.Error(
-				"target not found for delivery",
+					"failed to load target for recovered delivery",
 					"delivery_id", deliveries[i].ID,
 					"target_id", deliveries[i].TargetID,
+					"error", err,
 				)
 
 				continue
 			}
+		}
 
 		if !e.takeForRedispatch(
 			webhookDB, deliveries[i].ID,

internal/delivery/engine_lifecycle_test.go

@@ -2,6 +2,8 @@ package delivery_test
 
 import (
 	"context"
+	"fmt"
+	"path/filepath"
 	"testing"
 	"time"
 
@@ -269,3 +271,88 @@ 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 {
+	t.Helper()
+
+	deliveryID, task := seedLogTask(t, s)
+	task.TargetType = database.TargetTypeDatabase
+
+	s.Engine.Notify([]delivery.Task{task})
+
+	iWaitForDelivered(t, s.WebhookDB, deliveryID)
+
+	return filepath.Join(
+		filepath.Dir(s.DBMgr.DBPath(s.WebhookID)),
+		fmt.Sprintf("archive-%s.db", s.WebhookID),
+	)
+}
+
+// TestEngine_StopHookClosesArchives is the regression test for an
+// archive split across two files by a clean stop. The engine never
+// closed its archive writers, so after a stop the archived rows
+// could sit in archive-{id}.db-wal while archive-{id}.db held no
+// table at all, and copying the .db on its own gave an empty
+// database.
+func TestEngine_StopHookClosesArchives(t *testing.T) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	lc := startEngineViaHook(t, s.Engine)
+
+	path := deliverToArchive(t, s)
+	require.FileExists(
+		t, path+"-wal",
+		"an open archive should have a -wal for the stop to remove",
+	)
+
+	require.NoError(t, lc.hooks[0].OnStop(context.Background()))
+
+	wals, err := filepath.Glob(
+		filepath.Join(filepath.Dir(path), "archive-*.db-wal"),
+	)
+	require.NoError(t, err)
+	require.Empty(
+		t, wals, "a clean stop must leave no archive -wal behind",
+	)
+
+	// With no -wal beside it, the row can only be in the .db.
+	count, err := countArchivedRows(path)
+	require.NoError(t, err)
+	require.Equal(t, int64(1), count)
+}
+
+// TestEngine_StopHookTimeoutLeavesArchivesOpen covers a stop whose
+// budget runs out while a worker is still running. The archive
+// writers are left open, as a kill would leave them: closing them
+// would wait for any write in progress, and that worker would then
+// open new writers that nothing closes.
+func TestEngine_StopHookTimeoutLeavesArchivesOpen(t *testing.T) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	lc := startEngineViaHook(t, s.Engine)
+
+	deliverToArchive(t, s)
+
+	release := make(chan struct{})
+
+	t.Cleanup(func() {
+		close(release)
+		s.Engine.EvictWebhook(s.WebhookID)
+	})
+
+	s.Engine.ExportWedgeWorker(release)
+
+	requireStopHookExpires(t, lc.hooks[0], "delivery engine")
+
+	require.True(
+		t, s.Engine.ExportArchiveHandleOpen(s.WebhookID),
+		"a stop that timed out must not close archive writers",
+	)
+}

internal/delivery/engine_test.go

@@ -1166,6 +1166,10 @@ func TestIsForwardableHeader(t *testing.T) {
 	assert.False(t,
 		delivery.ExportIsForwardableHeader("Content-Length"),
 	)
+
+	assert.False(t,
+		delivery.ExportIsForwardableHeader("Content-Type"),
+	)
 }
 
 func TestTruncate(t *testing.T) {
@@ -1247,6 +1251,81 @@ func TestDoHTTPRequest_ForwardsHeaders(t *testing.T) {
 	)
 }
 
+// The event's stored inbound headers carry the same Content-Type the
+// receiver saved as the event's ContentType, so a delivery could send
+// it twice. It must go out exactly once, with a Content-Type configured
+// on the target winning, then the event's ContentType.
+func TestApplyRequestHeaders_SendsOneContentType(t *testing.T) {
+	t.Parallel()
+
+	cases := map[string]struct {
+		inbound    string
+		event      string
+		configured string
+		want       []string
+	}{
+		"inbound and event agree": {
+			inbound: testContentType,
+			event:   testContentType,
+			want:    []string{testContentType},
+		},
+		"inbound and event disagree": {
+			inbound: "text/plain",
+			event:   testContentType,
+			want:    []string{testContentType},
+		},
+		"event has none": {
+			inbound: testContentType,
+			want:    nil,
+		},
+		"target configures its own": {
+			inbound:    testContentType,
+			event:      testContentType,
+			configured: "application/xml",
+			want:       []string{"application/xml"},
+		},
+	}
+
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			inbound, err := json.Marshal(map[string][]string{
+				headerContentType: {tc.inbound},
+			})
+			require.NoError(t, err)
+
+			cfg := &delivery.HTTPTargetConfig{}
+			if tc.configured != "" {
+				cfg.Headers = map[string]string{
+					headerContentType: tc.configured,
+				}
+			}
+
+			req, err := http.NewRequestWithContext(
+				context.Background(),
+				http.MethodPost,
+				"https://target.example.com/hook",
+				http.NoBody,
+			)
+			require.NoError(t, err)
+
+			delivery.ExportApplyRequestHeaders(
+				req,
+				&database.Event{
+					Headers:     string(inbound),
+					ContentType: tc.event,
+				},
+				cfg,
+			)
+
+			assert.Equal(t,
+				tc.want, req.Header.Values(headerContentType),
+			)
+		})
+	}
+}
+
 func TestProcessDelivery_RoutesToCorrectHandler(
 	t *testing.T,
 ) {

internal/delivery/export_test.go

@@ -342,6 +342,31 @@ func (e *Engine) ExportRecoverRetryingDeliveries(
 	e.recoverRetryingDeliveries(webhookDB, webhookID)
 }
 
+// ExportFailMissingTarget exposes failMissingTarget, so a test can hand
+// it a delivery as a batch read it earlier.
+func (e *Engine) ExportFailMissingTarget(
+	webhookDB *gorm.DB,
+	webhookID string,
+	d *database.Delivery,
+) {
+	e.failMissingTarget(webhookDB, webhookID, d)
+}
+
+// ExportSendRecoveredDeliveries exposes sendRecoveredDeliveries, so a
+// test can hand it a target map that lacks a delivery's target.
+func (e *Engine) ExportSendRecoveredDeliveries(
+	ctx context.Context,
+	webhookDB *gorm.DB,
+	deliveries []database.Delivery,
+	webhookID string,
+	targetMap map[string]database.Target,
+	settled map[string]struct{},
+) {
+	e.sendRecoveredDeliveries(
+		ctx, webhookDB, deliveries, webhookID, targetMap, settled,
+	)
+}
+
 // ExportDeliveryCh returns the delivery channel.
 func (e *Engine) ExportDeliveryCh() chan Task {
 	return e.deliveryCh

internal/delivery/redirect_test.go

@@ -339,10 +339,11 @@ func TestRedirectPolicy_StopsAtHopCap(t *testing.T) {
 // The set the redirect policy strips is whatever the delivery path
 // actually put on the wire, so a header added to the forward set is
 // covered without a second edit. A header the event never carried
-// is not in the set, and the delivery path's own two are deliberately
-// excluded: Content-Type describes the body, which a 307 carries
-// across hosts, and the inbound User-Agent every real sender supplies
-// is overwritten before the request goes out.
+// is not in the set, and neither is the inbound Content-Type, because
+// it is not forwarded. Two more are deliberately excluded: a
+// Content-Type configured on the target describes the body, which a
+// 307 carries across hosts, and the inbound User-Agent every real
+// sender supplies is overwritten before the request goes out.
 func TestApplyRequestHeaders_ReportsOriginScopedNames(t *testing.T) {
 	t.Parallel()
 
@@ -371,6 +372,7 @@ func TestApplyRequestHeaders_ReportsOriginScopedNames(t *testing.T) {
 		&delivery.HTTPTargetConfig{
 			Headers: map[string]string{
 				probeHeaderName: probeHeaderValue,
+				"Content-Type":  testContentType,
 			},
 		},
 	)
@@ -378,7 +380,11 @@ func TestApplyRequestHeaders_ReportsOriginScopedNames(t *testing.T) {
 	assert.Equal(t,
 		[]string{probeHeaderName, inboundHeaderName}, names,
 		"both header classes are reported, and only those: "+
-			"Host is never forwarded, Content-Type and "+
-			"User-Agent are the delivery path's own",
+			"Host and the inbound Content-Type are never "+
+			"forwarded, User-Agent is the delivery path's own",
+	)
+	assert.NotContains(t, names, "Content-Type",
+		"a Content-Type configured on the target must survive "+
+			"a cross-origin 307/308 with the body it describes",
 	)
 }

internal/delivery/ssrf.go

@@ -26,7 +26,7 @@ var (
 		"hostname resolved to no IP addresses",
 	)
 	errBlockedIP = errors.New(
-		"blocked private/reserved IP range",
+		"blocked private, reserved or cloud metadata address",
 	)
 	errBlockedMetadata = errors.New(
 		"blocked link-local or cloud instance metadata " +
@@ -37,9 +37,10 @@ var (
 	)
 )
 
-// blockedNetworks contains all private/reserved IP ranges
-// that should be blocked to prevent SSRF attacks. An operator
-// can permit specific blocks out of this set with
+// 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.
 //
 //nolint:gochecknoglobals // package-level network list is appropriate here
@@ -122,6 +123,8 @@ func init() {
 		"::1/128",
 		"fc00::/7",
 		"fe80::/10",
+		// Azure WireServer, a public address that serves VM credentials.
+		"168.63.129.16/32",
 	})
 
 	// Every entry is named. The set must not grow or shrink
@@ -216,8 +219,8 @@ func matchesAny(networks []*net.IPNet, ip net.IP) bool {
 }
 
 // isBlockedIP checks whether an IP address falls within
-// any blocked private/reserved network range, before any
-// operator allowlist is considered.
+// the default blocklist, before any operator allowlist is
+// considered.
 func isBlockedIP(ip net.IP) bool {
 	return matchesAny(blockedNetworks, ip)
 }
@@ -320,7 +323,7 @@ func (g *Guard) allows(ip net.IP) bool {
 //
 //  1. alwaysBlockedNetworks is refused before the allowlist is
 //     consulted, so no configured CIDR reaches link-local or a
-//     cloud instance metadata endpoint.
+//     cloud metadata endpoint at a non-public address.
 //  2. The allowlist is consulted next, so a listed private
 //     network becomes reachable.
 //  3. Everything else keeps the default blocklist's answer.

internal/delivery/ssrf_allowlist_test.go

@@ -390,6 +390,41 @@ func TestGuardAllowlist_PublicUnaffected(t *testing.T) {
 	}
 }
 
+// TestGuardAllowlist_AzureWireServerReopenable covers Azure's
+// WireServer, a public address that serves VM credentials. The
+// default guard refuses it, but because it is public it sits in
+// the default blocklist rather than the unconditional set, so an
+// operator who lists it can reach it.
+func TestGuardAllowlist_AzureWireServerReopenable(t *testing.T) {
+	t.Parallel()
+
+	const wireServerIP = "168.63.129.16"
+
+	target := "http://" + wireServerIP + "/?comp=versions"
+
+	defaultGuard := delivery.NewTestGuard()
+
+	err := defaultGuard.ValidateTargetURL(context.Background(), target)
+	require.Error(t, err,
+		"WireServer must be refused with no allowlist set",
+	)
+	assert.NotContains(t, err.Error(), metadataRefusalClause,
+		"WireServer must be refused by the default blocklist, "+
+			"which an allowlist can override",
+	)
+
+	assertDialRefused(t, defaultGuard, target)
+
+	listed := delivery.NewTestGuard(
+		netip.MustParsePrefix(wireServerIP + "/32"),
+	)
+
+	assert.NoError(t,
+		listed.ValidateTargetURL(context.Background(), target),
+		"an operator who lists WireServer must be able to reach it",
+	)
+}
+
 // TestGuardCheckIP_BothPathsShareOneDecision asserts that the
 // validator and the dialer are not two policies that happen to
 // agree: both are defined in terms of checkIP, so the exported

internal/delivery/target_database.go

@@ -277,6 +277,24 @@ func (t *databaseTarget) evict(webhookID string) {
 	)
 }
 
+// evictAll evicts every cached archive writer, exactly as evict
+// does for one webhook. 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.
+func (t *databaseTarget) evictAll() {
+	t.mu.Lock()
+
+	writers := t.writers
+	t.writers = nil
+
+	t.mu.Unlock()
+
+	for _, w := range writers {
+		w.evict()
+	}
+}
+
 // 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

internal/delivery/target_database_evict_test.go

@@ -1,6 +1,7 @@
 package delivery_test
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"net/http"
@@ -361,3 +362,46 @@ func TestEvictWebhook_LaterDeliveryRecreatesWriter(t *testing.T) {
 		"a later delivery should recreate the writer",
 	)
 }
+
+// TestEngineStop_WriteAfterStopIsRefused proves the engine's stop
+// closes each archive writer the way deleting its webhook does: a
+// write that reaches a writer after the stop is refused, reopens
+// nothing and adds no row.
+func TestEngineStop_WriteAfterStopIsRefused(t *testing.T) {
+	t.Parallel()
+
+	eng, _ := evictTestEngine(t)
+
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"archived":true}`)
+	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+
+	eng.ExportDeliverDatabase(webhookDB, d)
+
+	w := eng.ExportArchiveWriterFor(event.WebhookID)
+	require.NotNil(t, w)
+	require.True(t, w.HandleOpen())
+
+	require.NoError(t, eng.ExportStop(context.Background()))
+
+	err := w.Write(evictTestRow("ev-after-stop"), 0)
+
+	require.ErrorIs(
+		t, err, delivery.ErrExportArchiveWriterEvicted,
+		"a write after the stop must be refused",
+	)
+	assert.False(
+		t, w.HandleOpen(),
+		"a refused write must not reopen the archive",
+	)
+	assert.False(
+		t, eng.ExportHasArchiveWriter(event.WebhookID),
+		"the stop should empty the registry",
+	)
+
+	count, err := countArchivedRows(w.Path())
+	require.NoError(t, err)
+	assert.Equal(
+		t, int64(1), count, "the refused row must not be written",
+	)
+}

internal/delivery/target_headers_test.go

@@ -11,10 +11,11 @@ import (
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
-// Literals these tests repeat, named so that the header name and the
+// Literals these tests repeat, named so that the header names and the
 // keep-forever archive config each have one definition.
 const (
 	headerAuthorization = "Authorization"
+	headerContentType   = "Content-Type"
 	bearerValue         = "Bearer abc"
 	archiveConfigNever  = "{\"expiry\":\"never\"}"
 )

internal/delivery/target_http.go

@@ -541,6 +541,11 @@ func isForwardableHeader(name string) bool {
 		"Upgrade", "Proxy-Authorization",
 		"Proxy-Connection", "Content-Length":
 		return false
+	case "Content-Type":
+		// applyRequestHeaders sets Content-Type itself. The receiver
+		// already stored this inbound value as the event's
+		// ContentType, so forwarding it too would send it twice.
+		return false
 	default:
 		return true
 	}
@@ -553,6 +558,10 @@ func isForwardableHeader(name string) bool {
 // policy strips exactly that set on a hop that leaves the origin,
 // so the forward set is decided here and only here — a header added
 // to it is covered off-origin without a second edit elsewhere.
+//
+// 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.
 func applyRequestHeaders(
 	req *http.Request,
 	event *database.Event,
@@ -573,10 +582,10 @@ func applyRequestHeaders(
 
 	req.Header.Set("User-Agent", "webhooker/1.0")
 
-	// Content-Type describes the body being sent rather than the
-	// sender, and the delivery path sets it from the event itself.
-	// A 307/308 preserves the body across hosts, so stripping it
-	// would send that body untyped.
+	// A Content-Type configured on the target describes the body
+	// being sent rather than the sender. A 307/308 preserves the
+	// body across hosts, so stripping it would send that body
+	// untyped.
 	delete(originScoped, "Content-Type")
 
 	// User-Agent is overwritten just above, so an inbound one never

internal/delivery/terminal_state_test.go

@@ -18,16 +18,17 @@ import (
 // https://git.eeqj.de/sneak/webhooker/issues/107: a delivery failed
 // with nothing in its event log to say why, and a retrying delivery
 // whose target was deleted, which used to keep sending and then never
-// terminalise.
+// terminalise. Section 4 is the same deleted-target gap for a pending
+// delivery: https://git.eeqj.de/sneak/webhooker/issues/293.
 
 // tUnknownType is a target type no build implements. It stands in for
 // a target whose type was written by a build that knew a type this one
 // does not.
 const tUnknownType = database.TargetType("pubsub")
 
-// tSeedDeletedTarget creates a target, a retrying delivery against it
-// with one recorded failed attempt, and then deletes the target the
-// way the source page does.
+// tSeedDeletedTarget creates a target, a delivery against it at the
+// given status with one recorded failed attempt, and then deletes the
+// target the way the source page does.
 //
 // It asserts the delete is soft, because that is the whole reason the
 // engine could not tell a deleted target from a target id that never
@@ -36,6 +37,7 @@ func tSeedDeletedTarget(
 	t *testing.T,
 	s iSetup,
 	name, url string,
+	status database.DeliveryStatus,
 ) string {
 	t.Helper()
 
@@ -51,8 +53,7 @@ func tSeedDeletedTarget(
 	)
 
 	d := iSeedDelivery(
-		t, s.WebhookDB, event.ID, targetID,
-		database.DeliveryStatusRetrying,
+		t, s.WebhookDB, event.ID, targetID, status,
 	)
 
 	iSeedFailedResult(t, s.WebhookDB, d.ID)
@@ -173,6 +174,7 @@ func TestRecoverSingleRetry_TargetDeleted(t *testing.T) {
 
 	deliveryID := tSeedDeletedTarget(
 		t, s, "gone-on-recovery", "http://example.com/hook",
+		database.DeliveryStatusRetrying,
 	)
 
 	s.Engine.ExportRecoverWebhookDeliveries(
@@ -210,6 +212,7 @@ func TestSweepSingleRetry_TargetDeleted(t *testing.T) {
 
 	deliveryID := tSeedDeletedTarget(
 		t, s, "gone-on-sweep", "http://example.com/hook",
+		database.DeliveryStatusRetrying,
 	)
 
 	// Twice, because the bug was an error the sweep repeated every
@@ -278,11 +281,11 @@ func TestSweepSingleRetry_TargetNeverExisted(t *testing.T) {
 	)
 }
 
-// TestFailMissingTargetRetry_WritesNoTargetRow holds the new terminal
-// path to the same rule as the existing one: no target row, and so no
+// TestFailMissingTarget_WritesNoTargetRow holds the new terminal path
+// to the same rule as the existing one: no target row, and so no
 // plaintext target config, may be written into the per-webhook event
 // database. See https://git.eeqj.de/sneak/webhooker/issues/206.
-func TestFailMissingTargetRetry_WritesNoTargetRow(
+func TestFailMissingTarget_WritesNoTargetRow(
 	t *testing.T,
 ) {
 	t.Parallel()
@@ -297,6 +300,7 @@ func TestFailMissingTargetRetry_WritesNoTargetRow(
 
 	deliveryID := tSeedDeletedTarget(
 		t, s, "credential-bearing", hookURL,
+		database.DeliveryStatusRetrying,
 	)
 
 	s.Engine.ExportSweepWebhookRetries(
@@ -529,3 +533,260 @@ func TestRecoverSingleRetry_TargetUnreadable_LeavesDeliveryAlone(
 
 	assert.Zero(t, s.Engine.ExportInflightHeld())
 }
+
+// --- 4. A pending delivery whose target is gone ---
+
+func TestRecoverPending_TargetDeleted(t *testing.T) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	deliveryID := tSeedDeletedTarget(
+		t, s, "gone-while-pending", "http://example.com/hook",
+		database.DeliveryStatusPending,
+	)
+
+	s.Engine.ExportRecoverWebhookDeliveries(
+		context.Background(), s.WebhookID,
+	)
+
+	iAssertStatus(
+		t, s.WebhookDB, deliveryID,
+		database.DeliveryStatusFailed,
+	)
+
+	last := tLastResult(t, s, deliveryID, 2)
+
+	assert.False(t, last.Success)
+	assert.Equal(t, 2, last.AttemptNum)
+	assert.Contains(t, last.Error, "gone-while-pending")
+	assert.Contains(t, last.Error, "was deleted")
+
+	assert.Empty(t, fDrain(s.Engine),
+		"a delivery whose target is gone was sent",
+	)
+	assert.Zero(t, s.Engine.ExportInflightHeld(),
+		"the terminal path leaked its ownership reference",
+	)
+}
+
+// TestRecoverPending_TargetDeleted_LeavesAnOwnedDeliveryAlone: the
+// terminal write takes ownership like every other recovery write, so a
+// delivery the engine still holds is not failed underneath its worker.
+func TestRecoverPending_TargetDeleted_LeavesAnOwnedDeliveryAlone(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	deliveryID := tSeedDeletedTarget(
+		t, s, "gone-but-owned", "http://example.com/hook",
+		database.DeliveryStatusPending,
+	)
+
+	require.True(t, s.Engine.ExportRetainDelivery(deliveryID))
+
+	s.Engine.ExportRecoverWebhookDeliveries(
+		context.Background(), s.WebhookID,
+	)
+
+	iAssertStatus(
+		t, s.WebhookDB, deliveryID,
+		database.DeliveryStatusPending,
+	)
+
+	assert.Len(t, iResults(t, s.WebhookDB, deliveryID), 1,
+		"a delivery the engine owns was failed underneath it",
+	)
+}
+
+// TestFailMissingTarget_LeavesASettledDeliveryAlone: the recovery paths
+// read their batch before taking ownership, and a worker may send a
+// delivery and let it go in between. The terminal write goes by the row
+// as it is now, not as the batch read it.
+func TestFailMissingTarget_LeavesASettledDeliveryAlone(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	deliveryID := tSeedDeletedTarget(
+		t, s, "gone-after-sending", "http://example.com/hook",
+		database.DeliveryStatusPending,
+	)
+
+	var batch database.Delivery
+
+	require.NoError(t, s.WebhookDB.First(
+		&batch, "id = ?", deliveryID,
+	).Error)
+
+	// A worker settles the delivery after the batch was read.
+	require.NoError(t, s.WebhookDB.Model(&database.Delivery{}).
+		Where("id = ?", deliveryID).
+		Update("status", database.DeliveryStatusDelivered).Error)
+
+	s.Engine.ExportFailMissingTarget(
+		s.WebhookDB, s.WebhookID, &batch,
+	)
+
+	iAssertStatus(
+		t, s.WebhookDB, deliveryID,
+		database.DeliveryStatusDelivered,
+	)
+
+	assert.Len(t, iResults(t, s.WebhookDB, deliveryID), 1,
+		"a delivery settled after the batch read was then failed",
+	)
+	assert.Zero(t, s.Engine.ExportInflightHeld())
+}
+
+// TestSweepPending_TargetDeleted sweeps twice over a batch that also
+// holds a healthy stranded delivery. The one whose target is gone is
+// failed once and then left alone; the healthy one is queued by the
+// first sweep and not again by the second.
+func TestSweepPending_TargetDeleted(t *testing.T) {
+	t.Parallel()
+
+	liveTargetID := uuid.New().String()
+	s := fSweepSetup(t, liveTargetID, "still-there")
+
+	deliveryID := tSeedDeletedTarget(
+		t, s, "gone-on-pending-sweep", "http://example.com/hook",
+		database.DeliveryStatusPending,
+	)
+	rAgePending(t, s.WebhookDB, deliveryID)
+
+	event := iSeedEvent(
+		t, s.WebhookDB, s.WebhookID, `{"target":"live"}`,
+	)
+
+	healthy := iSeedDelivery(
+		t, s.WebhookDB, event.ID, liveTargetID,
+		database.DeliveryStatusPending,
+	)
+	rAgePending(t, s.WebhookDB, healthy.ID)
+
+	ctx := context.Background()
+
+	s.Engine.ExportSweepWebhookRetries(ctx, s.WebhookID)
+
+	tasks := fDrain(s.Engine)
+	require.Len(t, tasks, 1,
+		"the first sweep did not queue the healthy delivery",
+	)
+	assert.Equal(t, healthy.ID, tasks[0].DeliveryID)
+
+	s.Engine.ExportSweepWebhookRetries(ctx, s.WebhookID)
+
+	assert.Empty(t, fDrain(s.Engine),
+		"the second sweep queued a delivery again",
+	)
+
+	iAssertStatus(
+		t, s.WebhookDB, deliveryID,
+		database.DeliveryStatusFailed,
+	)
+
+	last := tLastResult(t, s, deliveryID, 2)
+
+	assert.Contains(t, last.Error, "gone-on-pending-sweep")
+	assert.Contains(t, last.Error, "was deleted")
+}
+
+// TestSendRecoveredDeliveries_TargetMissingFromMap: the batch's target
+// map is empty when its query failed, so every delivery in the batch is
+// looked up on its own. A healthy one is sent to the target that lookup
+// finds.
+func TestSendRecoveredDeliveries_TargetMissingFromMap(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	targetID := uuid.New().String()
+
+	iCreateTarget(
+		t, s.MainDB, targetID, s.WebhookID, "found-on-lookup",
+		database.TargetTypeLog, "", 0,
+	)
+
+	event := iSeedEvent(
+		t, s.WebhookDB, s.WebhookID, `{"map":"empty"}`,
+	)
+
+	d := iSeedDelivery(
+		t, s.WebhookDB, event.ID, targetID,
+		database.DeliveryStatusPending,
+	)
+
+	s.Engine.ExportSendRecoveredDeliveries(
+		context.Background(), s.WebhookDB,
+		[]database.Delivery{d}, s.WebhookID,
+		map[string]database.Target{}, nil,
+	)
+
+	tasks := fDrain(s.Engine)
+	require.Len(t, tasks, 1,
+		"the healthy delivery was not queued exactly once",
+	)
+	assert.Equal(t, d.ID, tasks[0].DeliveryID)
+	assert.Equal(t, targetID, tasks[0].TargetID)
+	assert.Equal(t, database.TargetTypeLog, tasks[0].TargetType)
+
+	iAssertStatus(
+		t, s.WebhookDB, d.ID,
+		database.DeliveryStatusPending,
+	)
+}
+
+// TestRecoverPending_TargetUnreadable_LeavesDeliveryAlone: a failed
+// read of the main database is not a deleted target. Restart recovery
+// holds every pending delivery of the webhook in one batch, so failing
+// on this would fail all of them.
+func TestRecoverPending_TargetUnreadable_LeavesDeliveryAlone(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	targetID := uuid.New().String()
+
+	iCreateTarget(
+		t, s.MainDB, targetID, s.WebhookID, "healthy",
+		database.TargetTypeLog, "", 0,
+	)
+
+	event := iSeedEvent(
+		t, s.WebhookDB, s.WebhookID, `{"still":"pending"}`,
+	)
+
+	d := iSeedDelivery(
+		t, s.WebhookDB, event.ID, targetID,
+		database.DeliveryStatusPending,
+	)
+
+	sqlDB, err := s.MainDB.DB()
+	require.NoError(t, err)
+	require.NoError(t, sqlDB.Close())
+
+	s.Engine.ExportRecoverPendingDeliveries(
+		context.Background(), s.WebhookDB, s.WebhookID,
+	)
+
+	iAssertStatus(
+		t, s.WebhookDB, d.ID,
+		database.DeliveryStatusPending,
+	)
+
+	assert.Empty(t, iResults(t, s.WebhookDB, d.ID),
+		"an unreadable main database produced a terminal "+
+			"failure row",
+	)
+	assert.Empty(t, fDrain(s.Engine))
+	assert.Zero(t, s.Engine.ExportInflightHeld())
+}

internal/middleware/recoverer.go

@@ -133,6 +133,11 @@ func (w *recoverResponseWriter) Unwrap() http.ResponseWriter {
 // what the access log records and the metrics count, and outside the
 // sentryhttp handler, whose Repanic option depends on something
 // further out recovering what it re-raises.
+//
+// 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.
+// See https://git.eeqj.de/sneak/webhooker/issues/193.
 func (s *Middleware) Recoverer() func(http.Handler) http.Handler {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(
@@ -164,6 +169,8 @@ func (s *Middleware) Recoverer() func(http.Handler) http.Handler {
 					return
 				}
 
+				rw.Header().Del("Set-Cookie")
+
 				http.Error(
 					rw,
 					http.StatusText(

internal/middleware/recoverer_test.go

@@ -304,16 +304,44 @@ func TestRecovererRepanicsErrAbortHandler(t *testing.T) {
 	)
 }
 
+// TestRecovererDropsSetCookieFromTheRecovered500 covers a handler that
+// sets a cookie and a redirect target and then panics before sending
+// anything. A request that failed must not hand the client a
+// credential, so the 500 carries no cookie; Location is left alone.
+func TestRecovererDropsSetCookieFromTheRecovered500(t *testing.T) {
+	t.Parallel()
+
+	probe := newRecovererProbe(
+		t, false,
+		func(w http.ResponseWriter, _ *http.Request) {
+			w.Header().Set("Set-Cookie", "session=x")
+			w.Header().Set("Location", "/after")
+
+			panic(panicMarker)
+		},
+	)
+
+	resp, err := probe.get(t)
+	require.NoError(t, err)
+	require.NoError(t, resp.Body.Close())
+
+	assert.Equal(t, http.StatusInternalServerError, resp.StatusCode)
+	assert.Empty(t, resp.Cookies())
+	assert.Equal(t, "/after", resp.Header.Get("Location"))
+}
+
 // TestRecovererKeepsAnAlreadyCommittedResponse covers a handler that
 // panics after sending its status. The bytes are already on the wire,
-// so a second WriteHeader would change nothing the client sees and
-// would draw net/http's "superfluous response.WriteHeader" report.
+// cookie included, so a second WriteHeader would change nothing the
+// client sees and would draw net/http's "superfluous
+// response.WriteHeader" report.
 func TestRecovererKeepsAnAlreadyCommittedResponse(t *testing.T) {
 	t.Parallel()
 
 	probe := newRecovererProbe(
 		t, false,
 		func(w http.ResponseWriter, _ *http.Request) {
+			w.Header().Set("Set-Cookie", "session=x")
 			w.WriteHeader(committedStatus)
 			_, _ = w.Write([]byte("partial"))
 
@@ -331,6 +359,7 @@ func TestRecovererKeepsAnAlreadyCommittedResponse(t *testing.T) {
 
 	assert.Equal(t, committedStatus, resp.StatusCode)
 	assert.Equal(t, "partial", string(body))
+	assert.Len(t, resp.Cookies(), 1)
 
 	record := probe.panicRecord(t)
 	assert.Equal(t, panicMarker, record["panic"])

internal/server/routes.go

@@ -92,11 +92,25 @@ func (s *Server) setupGlobalMiddleware() {
 func (s *Server) setupRoutes() {
 	s.router.Get("/", s.h.HandleIndex())
 
-	s.router.Mount(
-		"/s",
-		http.StripPrefix("/s", http.FileServer(http.FS(static.Static))),
+	// Static assets answer GET and HEAD only. chi's default 405
+	// carries no Allow header, so this group supplies its own.
+	staticFiles := http.StripPrefix(
+		"/s", http.FileServer(http.FS(static.Static)),
 	)
 
+	s.router.Route("/s", func(r chi.Router) {
+		r.MethodNotAllowed(func(w http.ResponseWriter, _ *http.Request) {
+			w.Header().Set("Allow", "GET, HEAD")
+			http.Error(
+				w,
+				"Method Not Allowed",
+				http.StatusMethodNotAllowed,
+			)
+		})
+		r.Method(http.MethodGet, "/*", staticFiles)
+		r.Method(http.MethodHead, "/*", staticFiles)
+	})
+
 	s.router.Route("/api/v1", func(_ chi.Router) {
 		// API routes will be added here.
 	})

internal/server/routes_test.go

@@ -7,6 +7,7 @@ import (
 	"net/http/httptest"
 	"net/url"
 	"regexp"
+	"slices"
 	"strconv"
 	"strings"
 	"testing"
@@ -220,9 +221,21 @@ func (e *testEnv) csrfFrom(
 	// out of the markup has to be unescaped before it is submitted.
 	token := html.UnescapeString(match[1])
 
-	combined := make([]*http.Cookie, 0, len(cookies))
-	combined = append(combined, cookies...)
-	combined = append(combined, w.Result().Cookies()...)
+	// A cookie the page sets replaces the one of the same name, as in
+	// a browser. Sent both, the server would read the first, older one.
+	set := w.Result().Cookies()
+	combined := make([]*http.Cookie, 0, len(cookies)+len(set))
+
+	for _, c := range cookies {
+		replaced := slices.ContainsFunc(set, func(n *http.Cookie) bool {
+			return n.Name == c.Name
+		})
+		if !replaced {
+			combined = append(combined, c)
+		}
+	}
+
+	combined = append(combined, set...)
 
 	return token, combined
 }
@@ -396,13 +409,15 @@ func (e *testEnv) storedHash(t *testing.T, username string) string {
 
 // --- /s static group ---
 
-// TestStaticServesEveryMethod pins what the static mount actually
-// answers. chi's Mount registers the handler for all methods and
-// http.FileServer only special-cases HEAD (by suppressing the body),
-// so a POST or a DELETE to an asset is served the file rather than
-// refused. The README documents this; the test is what keeps the two
-// from drifting.
-func TestStaticServesEveryMethod(t *testing.T) {
+// TestStaticServesOnlyGetAndHead pins the methods the static group
+// answers: GET and HEAD are served the asset, and the other methods
+// chi routes (POST, PUT, DELETE and the rest) are refused with 405
+// and an Allow header naming those two. A method chi does not route,
+// such as PROPFIND, is refused with 405 by the top-level router
+// before it reaches the static group, so it gets no Allow header.
+// The README documents this; the test is what keeps the two from
+// drifting.
+func TestStaticServesOnlyGetAndHead(t *testing.T) {
 	t.Parallel()
 
 	env := newTestEnv(t)
@@ -417,6 +432,7 @@ func TestStaticServesEveryMethod(t *testing.T) {
 		http.MethodPost,
 		http.MethodPut,
 		http.MethodDelete,
+		"PROPFIND",
 	} {
 		t.Run(method, func(t *testing.T) {
 			t.Parallel()
@@ -428,18 +444,38 @@ func TestStaticServesEveryMethod(t *testing.T) {
 			w := httptest.NewRecorder()
 			env.router.ServeHTTP(w, req)
 
-			assert.Equal(t, http.StatusOK, w.Code,
-				"static mount answers every method")
-
-			if method == http.MethodHead {
-				assert.Empty(t, w.Body.Bytes(),
-					"HEAD must not carry a body")
-
-				return
-			}
-
+			switch method {
+			case http.MethodGet:
+				assert.Equal(t, http.StatusOK, w.Code)
 				assert.Equal(t, body, w.Body.Bytes(),
 					"the asset itself is returned")
+			case http.MethodHead:
+				assert.Equal(t, http.StatusOK, w.Code)
+				assert.Empty(t, w.Body.Bytes(),
+					"HEAD must not carry a body")
+			case "PROPFIND":
+				assert.Equal(
+					t, http.StatusMethodNotAllowed, w.Code,
+				)
+				assert.Empty(t, w.Header().Get("Allow"),
+					"chi refuses a method it does not route "+
+						"before the static group runs")
+				assert.NotContains(
+					t, w.Body.String(), string(body),
+					"a refused method must not get the asset",
+				)
+			default:
+				assert.Equal(
+					t, http.StatusMethodNotAllowed, w.Code,
+				)
+				assert.Equal(
+					t, "GET, HEAD", w.Header().Get("Allow"),
+				)
+				assert.NotContains(
+					t, w.Body.String(), string(body),
+					"a refused method must not get the asset",
+				)
+			}
 		})
 	}
 }
@@ -591,6 +627,59 @@ func TestPagesLogin_CorrectPasswordSurvivesASpentBudget(
 	)
 }
 
+// TestPagesLogin_CookiesFromAnEarlierDatabase is
+// https://git.eeqj.de/sneak/webhooker/issues/359. A new database
+// brings a new session key, and the operator's browser still holds
+// the session and CSRF cookies signed with the old one. Logging in
+// must work as from a fresh browser and leave cookies the new key
+// accepts.
+func TestPagesLogin_CookiesFromAnEarlierDatabase(t *testing.T) {
+	t.Parallel()
+
+	const (
+		username = "operator"
+		password = "correct-horse-battery-staple"
+	)
+
+	earlier := newTestEnv(t)
+	earlierID, _ := earlier.seedUser(t, username, password)
+	_, stale := earlier.csrfFrom(t, "/pages/login", nil)
+	stale = append(stale, earlier.authCookies(t, earlierID, username)...)
+
+	env := newTestEnv(t)
+	env.seedUser(t, username, password)
+
+	token, cookies := env.csrfFrom(t, "/pages/login", stale)
+
+	form := url.Values{}
+	form.Set("csrf_token", token)
+	form.Set("username", username)
+	form.Set("password", password)
+
+	w := env.post("/pages/login", form, cookies)
+	require.Equal(
+		t, http.StatusSeeOther, w.Code,
+		"a session cookie from another key must not fail the login",
+	)
+
+	// The response deletes the old session cookie and then sets the
+	// new one; a browser keeps the last.
+	var fresh *http.Cookie
+
+	for _, c := range w.Result().Cookies() {
+		if c.Name == session.SessionName {
+			fresh = c
+		}
+	}
+
+	require.NotNil(t, fresh, "login must set a session cookie")
+	assert.Equal(
+		t, "/sources",
+		env.get("/", []*http.Cookie{fresh}).Header().Get("Location"),
+		"the new session cookie must authenticate",
+	)
+}
+
 // --- /user/{username} group ---
 
 // TestPasswordChange_OversizeBody_RejectedAndPasswordUnchanged

internal/session/codec_test.go

@@ -19,8 +19,8 @@ import (
 )
 
 // The tests below exercise the securecookie codecs underneath the
-// store and nothing else: Session.Get only decodes, so no server-side
-// expiry check takes part in the result. They exist because
+// store and nothing else: they decode through the store itself, so no
+// server-side expiry check takes part in the result. They exist because
 // NewCookieStore gives its codecs a 30-day max age that assigning
 // store.Options does not override, which would let the codec accept a
 // cookie weeks past the cap the cookie attribute advertises.
@@ -75,10 +75,11 @@ func restamp(
 	return base64.URLEncoding.EncodeToString(payload)
 }
 
-// decodeCookie feeds value back through the store's decode path.
+// decodeCookie feeds value back through the store's decode path. It
+// asks the store rather than Session.Get, which treats a cookie that
+// does not decode as absent and so hides the codec's reason.
 func decodeCookie(
 	t *testing.T,
-	s *session.Session,
 	value string,
 ) (*sessions.Session, error) {
 	t.Helper()
@@ -94,7 +95,7 @@ func decodeCookie(
 		SameSite: http.SameSiteLaxMode,
 	})
 
-	sess, err := s.Get(req)
+	sess, err := session.NewStore(testKey()).Get(req, session.SessionName)
 	require.NotNil(t, sess)
 
 	return sess, err
@@ -105,7 +106,7 @@ func TestCodec_AcceptsCookieInsideAbsoluteCap(t *testing.T) {
 
 	s := testSession(t)
 
-	sess, err := decodeCookie(t, s, restamp(
+	sess, err := decodeCookie(t, restamp(
 		t,
 		issuedCookie(t, s),
 		time.Now().Add(-(testAbsoluteMaxAge-time.Hour)),
@@ -126,7 +127,7 @@ func TestCodec_RejectsCookiePastAbsoluteCap(t *testing.T) {
 
 	s := testSession(t)
 
-	sess, err := decodeCookie(t, s, restamp(
+	sess, err := decodeCookie(t, restamp(
 		t,
 		issuedCookie(t, s),
 		time.Now().Add(-(testAbsoluteMaxAge+time.Hour)),

internal/session/session.go

@@ -224,10 +224,22 @@ func New(
 }
 
 // Get retrieves a session for the request.
+//
+// A session cookie that does not decode -- one signed with an earlier
+// session key, say, because the database was made anew -- is treated
+// as absent: the caller gets a new, empty session and no error, and
+// the next save replaces the cookie.
 func (s *Session) Get(
 	r *http.Request,
 ) (*sessions.Session, error) {
-	return s.store.Get(r, SessionName)
+	sess, err := s.store.Get(r, SessionName)
+	if sess == nil {
+		return nil, err
+	}
+
+	// For a cookie that does not decode, gorilla/sessions returns a
+	// new, empty session alongside the error that is dropped here.
+	return sess, nil
 }
 
 // GetKey returns the raw 32-byte authentication key used for