Render admin page errors in the normal layout (closes #382)

Every 400, 403, 404 and 500 on an admin page now answers with an
error page in the normal layout: one fixed line for the status and a
link back to the webhook list, or to sign-in when nobody is signed
in. The router's handler for unknown paths, the CSRF middleware's
refusal and a panic in an admin page route group use the same page;
each such group has its own recoverer and error reporting for that.
The page always sends Cache-Control: no-store. Status codes are
unchanged. The receiver, the healthcheck and /metrics keep their
plain answers. If the error page cannot render, or panics, the answer
is the same status in plain text.

Model: opus-5-5

.dockerignore

@@ -3,10 +3,8 @@
 # stage of the Dockerfile.
 .git/
 bin/
-# Third-party browser assets are fetched and hash-verified inside the build by
-# script/fetch-assets. Excluding any host copy keeps a developer's working tree
-# from supplying the bytes that get shipped. The script and its
-# static/vendor.sha256 manifest stay in the context.
+# 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

.gitignore

@@ -46,7 +46,6 @@ temp/
 # CI cache barrier, written into the build context by the check workflow
 .ci-fingerprint
 
-# Third-party browser assets, fetched and hash-verified by
-# script/fetch-assets against static/vendor.sha256. Not committed:
-# REPO_POLICIES.md forbids minified bundles in version control.
+# Alpine.js, extracted by `make assets` from its tarball in 3p/, which is
+# what is committed.
 /static/js/alpine.min.js

Dockerfile

@@ -51,15 +51,8 @@ RUN go mod download
 # the lint stage above.
 COPY . .
 
-# Fetch the third-party browser assets the UI serves. They are not committed
-# (REPO_POLICIES.md forbids minified bundles in version control) and
-# .dockerignore keeps any host copy out of the build context, so this step is
-# the only way they enter the image. Each download is checked against a
-# hardcoded sha256 and the build fails on mismatch; make test re-checks the
-# hashes against the bytes go:embed actually put in the binary.
-RUN script/fetch-assets
-
-# Run tests and build
+# Run tests and build. Both first run script/assets, which extracts Alpine.js
+# from its tarball in 3p/.
 RUN make test
 
 # Version stamped into the binary. .dockerignore excludes .git/, so
@@ -67,8 +60,8 @@ RUN make test
 # 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.
 #
-# Declared here, below the test and asset steps, so a changed version
-# does not invalidate their cached layers.
+# Declared here, below the test step, so a changed version does not
+# invalidate its cached layer.
 ARG VERSION=unknown
 
 RUN make build VERSION="$VERSION"

Makefile

@@ -28,7 +28,7 @@ setup:
 	@script/setup
 
 assets:
-	@script/fetch-assets
+	@script/assets
 
 test:
 	@script/test
@@ -45,13 +45,13 @@ fmt-check:
 check:
 	@script/check
 
-build:
+build: assets
 	go build -ldflags '$(strip -X main.version=$(VERSION) $(GO_LDFLAGS))' -o bin/webhooker ./cmd/webhooker
 
 run: build
 	./bin/webhooker
 
-dev:
+dev: assets
 	go run ./cmd/webhooker
 
 deps:

README.md

@@ -21,9 +21,6 @@ before deploying one.
 - Go 1.26.1+ (the version in `go.mod`)
 - Docker (for linting, for the test stage of the CI gate, and for
   containerized deployment)
-- `curl`, used by `script/fetch-assets` to download the third-party
-  browser assets, which are not committed (`make bootstrap` installs
-  it if missing)
 
 golangci-lint is not a prerequisite and must not be installed on the
 host: `script/bootstrap` does not install it, and `make lint` runs the
@@ -36,9 +33,7 @@ digest-pinned linter image via `Dockerfile.lint`.
 git clone https://git.eeqj.de/sneak/webhooker.git
 cd webhooker
 
-# Install Go dependencies and the third-party browser assets.
-# `make deps` alone is not enough: it only runs go mod download/tidy,
-# and the checks below need the fetched assets.
+# Install the Go toolchain if missing, and the Go dependencies
 make bootstrap
 
 # Run all checks (test, lint, format check)
@@ -58,7 +53,7 @@ make docker
 ```bash
 make bootstrap  # Install all dependencies (idempotent)
 make setup      # Bootstrap + install git pre-commit hook
-make assets     # Fetch + verify third-party browser assets
+make assets     # Extract Alpine.js from 3p/ (test, check, build, dev run it)
 make fmt        # Format code (gofmt + goimports)
 make fmt-check  # Fail if gofmt would change anything (writes nothing)
 make lint       # Run golangci-lint in Docker (Dockerfile.lint)
@@ -147,7 +142,7 @@ TTY detection, and security headers are always applied.
 | `RETENTION_SWEEP_INTERVAL` | How often the retention reaper and archive sweeper run (Go duration, must be positive) | `1h` |
 | `SESSION_IDLE_TIMEOUT`  | Idle session timeout (Go duration)  | `24h`    |
 | `RECEIVER_RATE_LIMIT`   | Receiver requests/minute per IP per entrypoint (10x that per IP across the route) | `120` |
-| `TRUSTED_PROXIES`       | CIDRs whose forwarded headers are trusted (unset: all clients behind a proxy share one rate-limit bucket; a correct login password is never throttled either way) | `""` (none) |
+| `TRUSTED_PROXIES`       | CIDRs whose forwarded headers are trusted. A set value replaces the default. If any client can reach webhooker, or the proxy in front of it, from an RFC 1918 source address, set it to the proxy's address alone. See [Trusted proxies](#trusted-proxies) | `10.0.0.0/8,172.16.0.0/12,192.168.0.0/16` (RFC 1918) |
 | `ALLOWED_EGRESS_CIDRS`  | CIDRs that delivery targets may reach despite the SSRF blocklist. Read [Allowing egress to your own network](#allowing-egress-to-your-own-network) before setting it | `""` (none) |
 
 #### Allowing egress to your own network
@@ -162,6 +157,21 @@ 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 is all the default blocklist covers: the IPv4 private and reserved
+ranges; of IPv6, only loopback (`::1`), unique local addresses
+(`fc00::/7`) and link-local addresses (`fe80::/10`); and certain public
+addresses. 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. IBM Cloud, for example, serves its package
+mirrors, time servers and object storage on `161.26.0.0/16`, and the
+private endpoints of its own cloud services on `166.8.0.0/14`. Neither
+range hands out credentials that way: the token service among those
+endpoints issues a token only in exchange for something the caller
+presents, such as an API key. Reaching these services can be a
+legitimate delivery, and every cloud has some, so a partial list would
+promise coverage it does not give.
+
 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
@@ -379,41 +389,37 @@ unlocked.
 `TRUSTED_PROXIES` is a comma-separated list of CIDR blocks (a bare
 address such as `192.168.1.7` is accepted and treated as a single
 host), for example `192.168.1.7, 2001:db8::5`. It decides whose
-`X-Forwarded-For` header the rate limiters believe, so it should name
-the addresses of your reverse proxies and nothing else.
+`X-Forwarded-For` header the rate limiters believe, so it should cover
+the addresses of your reverse proxies.
 
 `X-Forwarded-For` is honoured **only** when the connecting peer is
 inside one of these blocks; for every other peer the client identity is
-the connection's own address and the header is ignored. The default is
-the empty list, which trusts nobody — anything else would let any
-client pick its own rate limit bucket, minting a fresh one per request
-or draining someone else's. Set it to the address of your reverse
-proxy, and to nothing wider. A set but unparseable value aborts
-startup.
+the connection's own address and the header is ignored. Unset (or
+empty), the list is the RFC 1918 private ranges: `10.0.0.0/8`,
+`172.16.0.0/12` and `192.168.0.0/16`. A set value replaces the default
+entirely. A set but unparseable value aborts startup.
 
-That default is safe against forged headers, but leaving it unset in
-production has a cost you must know about. Production runs behind a
-TLS-terminating reverse proxy, so with `TRUSTED_PROXIES` unset every
-request keys on the proxy's own address and all clients share a single
-bucket per limit. The receiver limits become service-wide ceilings,
-and the login endpoint's failure counting collapses onto one key, so a
-stranger's wrong passwords throttle every other client's wrong
-passwords.
+If any client can reach webhooker, or the proxy in front of it, from an
+RFC 1918 source address (directly, or through anything that can
+rewrite source addresses, such as NAT or a published container port),
+set `TRUSTED_PROXIES` to the proxy's address alone, or every rate
+limit, the webhook receiver's included, can be bypassed by those
+clients. The address to set is the `remoteIP` field of the
+`http request` log line for a request that came through the proxy.
+
+Behind a proxy the list does not cover, every request keys on the
+proxy's own address and all clients share a single bucket per limit.
+The receiver limits become service-wide ceilings, and the login
+endpoint's failure counting collapses onto one key, so a stranger's
+wrong passwords throttle every other client's wrong passwords. Set
+`TRUSTED_PROXIES` to that proxy's address to restore per-client
+buckets.
 
 What it cannot do is lock the operator out. The login endpoint
 verifies credentials **before** it consults any limit and charges only
 failures, so a correct password is never throttled no matter how full
 the bucket is. See [Rate Limiting](#rate-limiting).
 
-The remedy is to set `TRUSTED_PROXIES` to your reverse proxy's
-address, which restores per-client buckets. webhooker logs a warning
-at startup whenever `TRUSTED_PROXIES` is empty, in every environment,
-because behind a proxy every client shares one bucket in `dev` and
-`prod` alike. The warning is informational when nothing proxies to the
-process: with no proxy in front, the peer address is the client's own
-and the buckets are already per-client. See
-[Rate Limiting](#rate-limiting) for what each limit shares.
-
 `X-Real-IP` and `True-Client-IP` are **never** read, from any peer.
 Reverse proxies append to `X-Forwarded-For` but forward other client
 headers verbatim, so a single-valued header is client-controlled even
@@ -429,20 +435,10 @@ instead, since past such an entry the chain is not the shape assumed
 here. The peer address is likewise used when the header is absent or
 every hop in it is a trusted proxy.
 
-Two operator requirements follow:
-
-- Your proxy must **append** the peer address to `X-Forwarded-For`
-  (nginx `$proxy_add_x_forwarded_for`, HAProxy `option forwardfor`,
-  Caddy and AWS ALB by default), and must append a bare address with
-  no port.
-- List proxy hosts **only**. Any address inside `TRUSTED_PROXIES`
-  chooses its own rate-limit key: its `X-Forwarded-For` is walked, so
-  it can name a different address on every request to get a fresh
-  bucket each time, or name another client's address to drain that
-  client's bucket. Never list a block that also covers clients — a
-  broad `10.0.0.0/8` on a network where clients live in the same range
-  makes all three limits, including the unauthenticated webhook
-  receiver, silently bypassable by every client in the block.
+Your proxy must therefore **append** the peer address to
+`X-Forwarded-For` (nginx `$proxy_add_x_forwarded_for`, HAProxy
+`option forwardfor`, Caddy and AWS ALB by default), and must append a
+bare address with no port.
 
 #### Sessions
 
@@ -741,10 +737,15 @@ repository's `Dockerfile` and runs it. The app needs:
 - **Volume:** one host directory mounted at `/var/lib/webhooker`.
 - **Environment variables:**
     - `WEBHOOKER_ENVIRONMENT=prod`
-    - `TRUSTED_PROXIES`: your reverse proxy's address on that Docker
-      network. The `remoteIP` field of the `http request` log line for a
-      request that came through the proxy shows it; the health check's
-      own lines show `::1`. See [Trusted proxies](#trusted-proxies).
+    - `TRUSTED_PROXIES`: unset, it is the RFC 1918 ranges. Set it to
+      your reverse proxy's address alone if that address is outside
+      those ranges, or if any client can reach webhooker, or the proxy,
+      from an RFC 1918 source address (directly, or through anything
+      that can rewrite source addresses, such as NAT or a published
+      container port). The `remoteIP` field of the `http request` log
+      line for a request that came through the proxy shows that
+      address; the health check's own lines show `::1`. See
+      [Trusted proxies](#trusted-proxies).
     - Leave `BIND_ADDRESS` and `DATA_DIR` unset: the image sets
       `BIND_ADDRESS` to `0.0.0.0`, and `DATA_DIR` defaults to
       `/var/lib/webhooker`.
@@ -807,12 +808,16 @@ reports.
    behind a proxy means the `X-Forwarded-Proto` header. The block below
    sets it; without it every request is read as plaintext and cookies
    ship without `Secure`. See [Configuration](#configuration).
-3. **Set `TRUSTED_PROXIES` to the proxy's address.** Unset, every rate
-   limiter keys on the connecting peer, which behind a proxy is the
-   proxy on every request: all clients collapse into one global bucket
-   per limit and the receiver's per-IP limits become service-wide
-   ceilings. See [Trusted proxies](#trusted-proxies). List the proxy
-   and nothing else.
+3. **Make sure `TRUSTED_PROXIES` covers the proxy's address.** For a
+   proxy it does not cover, every rate limiter keys on the proxy, so
+   all clients share one bucket per limit. Unset, the list is the RFC
+   1918 ranges, which do not cover a proxy that reaches the binary
+   itself over loopback (the binary bound to `127.0.0.1`). With the
+   image, the address to check is the `remoteIP` field of the
+   `http request` log line for a request that came through the proxy.
+   If any client can reach webhooker, or the proxy, from an RFC 1918
+   source address, set the list to the proxy's address alone. See
+   [Trusted proxies](#trusted-proxies).
 4. **Send `Host` as `$http_host`, not `$host`.** `$host` strips the
    port. webhooker's Origin/Referer check compares against the host it
    was given, so on any port other than 443 `$host` makes every form
@@ -1221,14 +1226,15 @@ This repository adheres to the
 standard: normalized scripts in `script/` are the entrypoints for the
 development workflow. Ten of the Makefile's seventeen targets are thin
 shims that call them; `build`, `run`, `dev`, `deps`, `clean`, `css` and
-`version` are inline commands with no script behind them, though
-`build` and `version` both take their value from `script/version`.
+`version` are inline commands with no script behind them, though `build`,
+`run` and `dev` first run `script/assets`, and `build` and `version` both
+take their value from `script/version`.
 
-`make check` needs the third-party browser assets in `static/`, which
-are not committed, so run `make bootstrap` (or just `make assets`) once
-after cloning. Without them the tests fail with a message naming that
-remedy. `make check` does not fetch them itself because it must not
-change any files in the repo.
+`script/test`, `make build` and `make dev` each run `script/assets`
+first, which writes the ignored `static/js/alpine.min.js` (see
+[Third-party browser assets](#third-party-browser-assets)), so
+`make test`, `make check` and the pre-commit hook work on a fresh clone
+without a separate step.
 
 We provide:
 
@@ -1236,8 +1242,8 @@ We provide:
 - `script/setup` — make a fresh clone ready for development
   (bootstrap, then install-precommit)
 - `script/projectname` — output the project name ("webhooker")
-- `script/fetch-assets` — download the third-party browser assets into
-  `static/`, verifying each against its pinned sha256
+- `script/assets` — extract Alpine.js from its tarball in `3p/` (see
+  [Third-party browser assets](#third-party-browser-assets))
 - `script/test` — run the test suite
 - `script/lint` — run golangci-lint in Docker (see Linting below)
 - `script/fmt` — format all code (writes)
@@ -1259,24 +1265,25 @@ We provide:
 
 ## Third-party browser assets
 
-The web UI serves one third-party script, Alpine.js. It is **not** committed:
-a minified bundle in the tree is unreviewable, and `REPO_POLICIES.md` bars
-both committed build artifacts and unpinned external references.
+The web UI serves one third-party script, Alpine.js. Its npm package tarball
+is committed as `3p/alpinejs-3.14.9.tgz`, byte for byte as the npm registry
+publishes it. It is a dependency, not this repo's build output, so
+`REPO_POLICIES.md`'s rule against committed build artifacts does not apply.
+The directory is `3p/` rather than `vendor/` because Go treats a root
+`vendor/` directory as its module vendor directory.
 
-Instead `script/fetch-assets` downloads it from a pinned URL, checks the
-download against a hardcoded sha256, and installs it under `static/`. The
-sha256 of every installed asset is recorded in `static/vendor.sha256`, and
-`static/vendor_test.go` re-hashes the bytes `go:embed` put in the binary
-against that manifest — so the pin is enforced on what actually ships, not
-merely written down. Any mismatch fails the build.
+`script/assets` (`make assets`) extracts the browser build,
+`package/dist/cdn.min.js`, from the tarball to `static/js/alpine.min.js`,
+where `go:embed` picks it up. `script/test`, `make build` and `make dev` run
+it first, and the Dockerfile builds through `make test` and `make build`, so
+nothing downloads Alpine.js. The extracted file is not committed, and
+`.dockerignore` keeps any host copy out of the build context.
 
-`make bootstrap` runs the fetch for local development, and the Dockerfile
-runs it in the build stage; `.gitignore` and `.dockerignore` keep the
-artifact out of both the repo and the build context.
-
-To move to a new version: update the version, URL, and tarball sha256 in
-`script/fetch-assets` and the asset sha256 in `static/vendor.sha256`, then
-run `make assets && make check`.
+To move to a new version: download
+`https://registry.npmjs.org/alpinejs/-/alpinejs-<version>.tgz`, check it
+against the `dist.integrity` hash listed at
+`https://registry.npmjs.org/alpinejs/<version>`, replace the tarball in `3p/`
+with it, update its file name in `script/assets`, and run `make check`.
 
 ## Rationale
 
@@ -1363,10 +1370,11 @@ It uses:
 - **[go-chi/httprate](https://github.com/go-chi/httprate)** for
   sliding-window rate limiting of the password-change and webhook
   receiver endpoints. The bucket is per client IP only when
-  `TRUSTED_PROXIES` names the reverse proxy; unset, every client
-  behind that proxy shares one bucket per limit. The login endpoint
-  counts failed attempts itself instead, so that a correct password is
-  never throttled (see [Rate Limiting](#rate-limiting))
+  `TRUSTED_PROXIES` covers the reverse proxy (by default it covers the
+  RFC 1918 private ranges); otherwise every client behind that proxy
+  shares one bucket per limit. The login endpoint counts failed
+  attempts itself instead, so that a correct password is never
+  throttled (see [Rate Limiting](#rate-limiting))
 - **[Prometheus](https://prometheus.io)** for metrics, served at
   `/metrics` behind basic auth
 - **[Sentry](https://sentry.io)** for optional error reporting
@@ -1439,7 +1447,7 @@ A registered user of the webhooker service.
 | Field      | Type     | Description |
 | ---------- | -------- | ----------- |
 | `id`       | UUID     | Primary key |
-| `username` | string   | Unique login name |
+| `username` | string   | Unique login name, at most 1024 bytes so that it fits in the session cookie |
 | `password` | string   | Argon2id hash (never exposed via API) |
 
 **Relations:** Has many Webhooks. Has many APIKeys.
@@ -1645,6 +1653,7 @@ data for auditing, for replay, and for resubmission.
 | `headers`      | JSON   | Complete request headers |
 | `body`         | text   | Raw request body |
 | `content_type` | string | Content-Type header value |
+| `body_bytes`   | integer | The body's size in bytes, recorded when the event is stored, on receipt and on resubmit |
 | `resubmitted_from_id` | UUID | The event this one was copied from by a resubmit (nullable; empty for an event that arrived on the receiver). Not a foreign key: the source event can be reaped by retention while its copies remain |
 
 **Relations:** Belongs to Webhook. Belongs to Entrypoint. Has many
@@ -2379,14 +2388,14 @@ Removing either cap fails 14 subtests.
 
 `internal/middleware/logbound_test.go` and
 `internal/handlers/logbound_test.go` drive 8 KB of client-chosen text
-at each of these — 1 KB at `invalid password`, whose accounts are
-shared with the successful-login line, where a username past 4 KB
-overflows the session cookie and answers 500 before that line is
-written — through both handlers, and through seven fills: plain text
-as the baseline, and then the quotation mark, backslash, tab, newline,
-C0 control and astral non-printable, six characters the wider of the
-two handlers spends more on than the client spent sending them. Every
-case holds each line to the 2,560-byte ceiling. That per-line ceiling
+at each of these — just under 1 KB at `invalid password`, whose
+accounts are shared with the successful-login line and so must stay
+within the 1024-byte username limit — through both handlers, and
+through seven fills: plain text as the baseline, and then the
+quotation mark, backslash, tab, newline, C0 control and astral
+non-printable, six characters the wider of the two handlers spends
+more on than the client spent sending them. Every case holds each
+line to the 2,560-byte ceiling. That per-line ceiling
 is what the figure above states, and every row establishes it.
 
 Three of the sites go further and bound the whole flood's output — the
@@ -2536,47 +2545,44 @@ the tree is checked out: four checkouts have reported 3,959, 3,961,
 client-supplied field was cut, and that the shipped chain's stack
 arrived uncut — never the numbers.
 
-Every limiter here — receiver, login, and password change — identifies
-the client the same way, through one shared key function: the
-connection's own address, unless the peer is listed in
-`TRUSTED_PROXIES`, in which case the forwarded client address is used
-instead. That address becomes a bucket by family: IPv4 keys on the full
-address, IPv6 on its `/64` prefix. A routed `/64` is the normal
+Every limiter here — receiver, login, password change, delivery replay
+and event resubmit — identifies the client the same way, through one
+shared key function: the connection's own address, unless the peer is
+inside `TRUSTED_PROXIES`, in which case the forwarded client address is
+used instead. That address becomes a bucket by family: IPv4 keys on
+the full address, IPv6 on its `/64` prefix. A routed `/64` is the normal
 residential and mobile IPv6 allocation, so keying IPv6 per address would
 let one subscriber rotate source addresses and mint a fresh bucket per
 request, evading these limits at the network layer without spoofing
 anything; the cost is that distinct clients inside one `/64` share a
 bucket. IPv4-mapped addresses (`::ffff:1.2.3.4`) key as the IPv4 address
-they carry. See [Trusted proxies](#trusted-proxies). Deployed without that
-variable set, a client behind a reverse proxy shares one bucket with
-every other client behind the same proxy. Set `TRUSTED_PROXIES` to the
-proxy's address to get per-client limits back. What the shared bucket
+they carry. See [Trusted proxies](#trusted-proxies). When that variable
+does not cover the reverse proxy, a client behind it shares one bucket
+with every other client behind the same proxy. Set `TRUSTED_PROXIES` to
+the proxy's address to get per-client limits back. What the shared bucket
 costs is not the same for every limiter, and the two cases pull in
 opposite directions:
 
 - For the **receiver** limits it costs throughput, which is the safe
   direction to be wrong in: sharing can only make a limit bind sooner,
   never let a sender past it. It matters more for the aggregate limit
-  than for the per-entrypoint one: with `TRUSTED_PROXIES` unset behind
-  the reverse proxy a production deployment is required to run behind,
-  every request keys on the proxy, so the aggregate limit becomes a
-  service-wide ceiling of 1200 requests per minute across all senders
-  and all entrypoints, where the per-entrypoint limit's capacity still
-  grows with the number of entrypoints. Any deployment with more than a
-  handful of busy entrypoints must set `TRUSTED_PROXIES`.
+  than for the per-entrypoint one: with every request keyed on the
+  proxy, the aggregate limit becomes a service-wide ceiling of 1200
+  requests per minute across all senders and all entrypoints, where the
+  per-entrypoint limit's capacity still grows with the number of
+  entrypoints.
 - For the **login and password-change** limits it costs precision, not
   availability. Login failures from every client land in one counter,
   so a stranger's wrong passwords make the operator's own wrong
   passwords answer `429` sooner; the operator's _correct_ password is
-  never affected, because it is never counted. Production deployments
-  should still set `TRUSTED_PROXIES`; webhooker warns at startup
-  whenever it is empty, in any environment.
+  never affected, because it is never counted.
 
 #### The login endpoint
 
 The login `POST` is the one endpoint with no pre-emptive limiter in
 front of it, and that is deliberate. A limiter that spends budget on
-arrival is a lockout in this deployment shape: sharing one bucket, a
+arrival is a lockout wherever clients share one bucket, as they do
+behind a reverse proxy that `TRUSTED_PROXIES` does not cover: a
 stranger sending five POSTs a minute — about 0.08 requests per second,
 from anywhere — keeps it permanently full, and the operator has no
 second administrative path. So the handler inverts the order:
@@ -2673,8 +2679,10 @@ re-fills both verification slots on its first two requests. The
 remedies are to block the source at the reverse proxy, or to
 rate-limit `POST /pages/login` there — the one place a limit can be
 applied without reintroducing the lockout, because the proxy sees the
-real client address. Setting `TRUSTED_PROXIES` does not stop the
-saturation, but it makes the source visible in the failure logs.
+real client address. `TRUSTED_PROXIES` does not stop the saturation.
+The flood's source is in the proxy's access log: webhooker's own logs
+record the proxy's address, not the client's (see
+[Deployment behind a reverse proxy](#deployment-behind-a-reverse-proxy)).
 
 Finer-grained per-webhook rate limits (configured in the web UI and
 enforced in the webhook handler) can layer on top of this env-level
@@ -2755,6 +2763,8 @@ imports. The entry point is `cmd/webhooker/main.go`.
 
 ```
 webhooker/
+├── 3p/
+│   └── alpinejs-3.14.9.tgz    # Alpine.js npm package, extracted by make assets
 ├── cmd/webhooker/
 │   └── main.go               # Entry point: subcommand dispatch; no args locks DATA_DIR and wires fx
 ├── internal/
@@ -2848,8 +2858,7 @@ webhooker/
 │   ├── css/tailwind.css       # Generated stylesheet the pages load
 │   ├── css/style.css          # Older hand-written stylesheet, no longer loaded
 │   ├── js/app.js              # Progressive-enhancement copy-to-clipboard
-│   ├── js/alpine.min.js       # Alpine.js, fetched by script/fetch-assets, not committed
-│   └── vendor.sha256          # Pinned hashes the fetched assets are verified against
+│   └── js/alpine.min.js       # Alpine.js, extracted from 3p/ by make assets, not committed
 ├── templates/                 # Go HTML templates (base, login, sources, etc.)
 ├── script/                    # Scripts to Rule Them All entrypoints
 ├── Dockerfile                 # Three stages: lint, test+build, Alpine runtime
@@ -3031,10 +3040,9 @@ check, see [The login endpoint](#the-login-endpoint).
   It runs behind session auth, so only a client already holding a
   valid session reaches it, and an operator throttled out of changing
   a password can still log in. The bucket is per client IP only when
-  `TRUSTED_PROXIES` names the reverse proxy; unset, every client
+  `TRUSTED_PROXIES` covers the reverse proxy; otherwise every client
   shares one bucket, which costs precision rather than availability
-  (see [Rate Limiting](#rate-limiting)). webhooker warns at startup
-  whenever `TRUSTED_PROXIES` is empty
+  (see [Rate Limiting](#rate-limiting))
 - Prometheus metrics behind basic auth
 - Static assets embedded in binary (no filesystem access needed at
   runtime)
@@ -3161,14 +3169,14 @@ version is fixed independently of the compiler's:
    `make fmt-check`, then `golangci-lint config verify` and
    `golangci-lint run`, both with `--network=none`.
 2. **Builder stage** (`golang:1.26.1-bookworm`) — depends on the lint
-   stage passing (it copies a file from it), runs `script/fetch-assets`
-   to download and verify the third-party browser assets, then runs
-   `make test` and `make build`, and finally 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 [Version stamping](#version-stamping)).
+   stage passing (it copies a file from it), runs `make test` and
+   `make build` (both extract Alpine.js from `3p/` first), and finally
+   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
+   [Version stamping](#version-stamping)).
 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

TODO.md

@@ -387,7 +387,7 @@ point of the branch.
 - 2026-03-05 security headers middleware, session regeneration on
   login, request body size limits (#41)
 - 2026-03-04 tests for delivery, middleware, and session packages
-  (#32); removed globals.Buildarch (#31)
+  (#32); removed the build-architecture global (#31)
 - 2026-03-04 1.0 MVP merge: Webhook/Entrypoint/Target rename, core
   delivery engine with bounded worker pool and circuit breaker,
   parallel fan-out, per-webhook event databases, management UI (#16)

go.mod

@@ -4,6 +4,7 @@ go 1.26.1
 
 require (
 	github.com/99designs/basicauth-go v0.0.0-20230316000542-bf6f9cbbf0f8
+	github.com/dustin/go-humanize v1.0.1
 	github.com/getsentry/sentry-go v0.25.0
 	github.com/go-chi/chi v1.5.5
 	github.com/go-chi/cors v1.2.1
@@ -29,7 +30,6 @@ require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
-	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/gorilla/securecookie v1.1.2 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect

internal/config/config.go

@@ -75,6 +75,11 @@ const (
 	// internet-exposed endpoint.
 	defaultReceiverRateLimit = 120
 
+	// defaultTrustedProxies is TRUSTED_PROXIES when it is unset: the
+	// RFC 1918 private ranges, which a reverse proxy reaching the
+	// process over a Docker network or a private LAN connects from.
+	defaultTrustedProxies = "10.0.0.0/8,172.16.0.0/12,192.168.0.0/16"
+
 	// maxPort is the highest valid TCP port number. The lower
 	// bound (at least 1) is enforced by envPositiveInt.
 	maxPort = 65535
@@ -172,13 +177,14 @@ type Config struct {
 
 	// TrustedProxies is the set of networks whose members are
 	// allowed to speak for the client with X-Forwarded-For, the
-	// only forwarded header read. It is empty unless
-	// TRUSTED_PROXIES is set, and empty means no peer is
-	// trusted: forwarded headers are then ignored entirely and
-	// clients are identified by the connection's own address.
-	// Members can choose their own rate-limit key, so this must
-	// name proxy hosts only, never a block that also covers
-	// clients.
+	// only forwarded header read. Unless TRUSTED_PROXIES is set it
+	// is the RFC 1918 private ranges (defaultTrustedProxies); a set
+	// value replaces them. If any client can reach the process, or
+	// the proxy in front of it, from an RFC 1918 source address
+	// (directly, or through anything that can rewrite source
+	// addresses, such as NAT or a published container port), it
+	// must be set to the proxy's address alone, or every rate limit
+	// can be bypassed by those clients.
 	TrustedProxies []netip.Prefix
 
 	// AllowedEgressCIDRs is the set of networks a delivery target
@@ -460,14 +466,15 @@ func parseCIDR(entry string) (netip.Prefix, error) {
 
 // envPrefixList returns the value of the named environment variable
 // parsed as a comma-separated list of CIDR blocks (bare addresses
-// allowed). An unset, empty, or blank value yields an empty list. A
-// set value containing an unparseable entry is a hard error naming
-// the key and the bad entry, so startup fails loudly rather than
-// silently running with a list the operator did not intend.
-func envPrefixList(key string) ([]netip.Prefix, error) {
+// allowed). An unset, empty, or blank value is read as defaultValue
+// instead. A set value containing an unparseable entry is a hard
+// error naming the key and the bad entry, so startup fails loudly
+// rather than silently running with a list the operator did not
+// intend.
+func envPrefixList(key, defaultValue string) ([]netip.Prefix, error) {
 	v := strings.TrimSpace(os.Getenv(key))
 	if v == "" {
-		return nil, nil
+		v = defaultValue
 	}
 
 	var prefixes []netip.Prefix
@@ -681,12 +688,12 @@ func loadFromEnv() (*Config, error) {
 		return nil, err
 	}
 
-	trustedProxies, err := envPrefixList("TRUSTED_PROXIES")
+	trustedProxies, err := envPrefixList("TRUSTED_PROXIES", defaultTrustedProxies)
 	if err != nil {
 		return nil, err
 	}
 
-	allowedEgressCIDRs, err := envPrefixList("ALLOWED_EGRESS_CIDRS")
+	allowedEgressCIDRs, err := envPrefixList("ALLOWED_EGRESS_CIDRS", "")
 	if err != nil {
 		return nil, err
 	}
@@ -760,50 +767,6 @@ func (c *Config) warnEgressAllowlist(log *slog.Logger) {
 	)
 }
 
-// warnSharedRateLimitBucket logs a startup warning whenever
-// TRUSTED_PROXIES is empty, in any environment.
-//
-// With no trusted proxies every rate limiter keys on the connecting
-// peer's address. Whether that is harmless or dangerous depends on
-// what is in front of the process, which this code cannot observe:
-// with nothing in front, the peer is the client and the limits are
-// per-client as intended; behind a reverse proxy the peer is the proxy
-// for every request, so all clients share one bucket per limiter.
-//
-// The login endpoint no longer spends budget on arrival — it verifies
-// credentials first and charges only failures — so a shared bucket
-// cannot deny the operator a correct password. What it does collapse
-// is the failure counting: one client's wrong passwords throttle
-// everyone else's wrong passwords, and the receiver's limits become
-// service-wide ceilings.
-//
-// The warning is deliberately not gated on WEBHOOKER_ENVIRONMENT:
-// behind a proxy every client shares one bucket in dev and prod alike.
-//
-// The default of trusting nobody is deliberate — trusting forwarded
-// headers from arbitrary peers lets any client choose its own bucket —
-// so this warns rather than failing startup or changing the key.
-func (c *Config) warnSharedRateLimitBucket(log *slog.Logger) {
-	if len(c.TrustedProxies) > 0 {
-		return
-	}
-
-	log.Warn(
-		"TRUSTED_PROXIES is empty: every rate limit keys on the "+
-			"connecting peer's address. With nothing proxying to "+
-			"this process that is the client itself and the limits "+
-			"are per-client as intended. Behind a reverse proxy the "+
-			"peer is the proxy on every request, so all clients "+
-			"share one bucket per limit: the receiver limits become "+
-			"service-wide ceilings, and one client's failed logins "+
-			"throttle every other client's failed logins — a "+
-			"correct password still gets in. If anything proxies to "+
-			"this process, set TRUSTED_PROXIES to its address.",
-		"environment", c.Environment,
-		"trustedProxies", len(c.TrustedProxies),
-	)
-}
-
 // New creates a Config by reading environment variables.
 //
 //nolint:revive // lc parameter is required by fx even if unused.
@@ -849,7 +812,6 @@ func New(lc fx.Lifecycle, params ConfigParams) (*Config, error) {
 		"hasMetricsAuth", s.MetricsAuthEnabled(),
 	)
 
-	s.warnSharedRateLimitBucket(log)
 	s.warnEgressAllowlist(log)
 
 	return s, nil

internal/config/config_test.go

@@ -551,6 +551,11 @@ func testReceiverRateLimitSuccess(
 }
 
 func TestTrustedProxies(t *testing.T) {
+	// Unset, the RFC 1918 private ranges are trusted, so a reverse
+	// proxy on a Docker network or a private LAN is covered without
+	// configuration.
+	defaultProxies := []string{cidrPrivateV4, "172.16.0.0/12", "192.168.0.0/16"}
+
 	tests := []struct {
 		name        string
 		set         bool
@@ -559,18 +564,21 @@ func TestTrustedProxies(t *testing.T) {
 		expected    []string
 	}{
 		{
-			// The default must be "trust nobody": an empty list
-			// means forwarded headers are ignored, never that
-			// every peer may speak for the client.
 			name:     caseUnsetUsesDefault,
 			set:      false,
-			expected: []string{},
+			expected: defaultProxies,
 		},
 		{
-			name:     "blank value trusts nothing",
+			name:     "blank value uses default",
 			set:      true,
 			value:    "  ",
-			expected: []string{},
+			expected: defaultProxies,
+		},
+		{
+			name:     "set value replaces the default entirely",
+			set:      true,
+			value:    "203.0.113.7",
+			expected: []string{"203.0.113.7/32"},
 		},
 		{
 			name:  caseValidValueParsed,
@@ -845,101 +853,6 @@ func TestEgressAllowlistWarning(t *testing.T) {
 	}
 }
 
-// TestSharedRateLimitBucketWarning covers the startup warning that
-// tells an operator a deployment behind a reverse proxy shares one
-// rate-limit bucket between every client, which turns the receiver
-// limits into service-wide ceilings and collapses login failure
-// counting. It must fire whenever TRUSTED_PROXIES is empty, in any
-// environment, because behind a proxy every client shares one bucket
-// in dev and prod alike. It stays quiet once proxies are named.
-func TestSharedRateLimitBucketWarning(t *testing.T) {
-	tests := []struct {
-		name           string
-		environment    string
-		trustedProxies string
-		expectWarning  bool
-	}{
-		{
-			name:          "prod without trusted proxies warns",
-			environment:   config.EnvironmentProd,
-			expectWarning: true,
-		},
-		{
-			name:           "prod with trusted proxies is quiet",
-			environment:    config.EnvironmentProd,
-			trustedProxies: cidrPrivateV4,
-			expectWarning:  false,
-		},
-		{
-			name:          "dev without trusted proxies warns",
-			environment:   config.EnvironmentDev,
-			expectWarning: true,
-		},
-		{
-			name:           "dev with trusted proxies is quiet",
-			environment:    config.EnvironmentDev,
-			trustedProxies: cidrPrivateV4,
-			expectWarning:  false,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			// Cannot use t.Parallel() here because t.Setenv
-			// is incompatible with parallel subtests.
-			t.Setenv("WEBHOOKER_ENVIRONMENT", tt.environment)
-
-			if tt.trustedProxies == "" {
-				require.NoError(
-					t, os.Unsetenv("TRUSTED_PROXIES"),
-				)
-			} else {
-				t.Setenv("TRUSTED_PROXIES", tt.trustedProxies)
-			}
-
-			var buf bytes.Buffer
-
-			log := slog.New(slog.NewJSONHandler(
-				&buf, &slog.HandlerOptions{
-					Level: slog.LevelDebug,
-				},
-			))
-
-			require.NoError(
-				t,
-				config.WarnSharedRateLimitBucketForTest(log),
-			)
-
-			if !tt.expectWarning {
-				assert.Empty(t, buf.String())
-
-				return
-			}
-
-			logged := buf.String()
-
-			assert.Contains(t, logged, `"level":"WARN"`)
-			assert.Contains(t, logged, "TRUSTED_PROXIES")
-			assert.Contains(t, logged, "share one bucket")
-			assert.Contains(
-				t, logged, "throttle every other client's failed logins",
-			)
-			// The warning must not claim a lockout the login
-			// endpoint no longer permits: credentials are verified
-			// before any budget is spent.
-			assert.Contains(
-				t, logged, "a correct password still gets in",
-			)
-			// The text must stay accurate for a developer with
-			// nothing in front of the process, where an empty
-			// list costs nothing.
-			assert.Contains(
-				t, logged, "nothing proxying to this process",
-			)
-		})
-	}
-}
-
 // metricsEnv describes what one subtest below puts in the
 // environment for a single METRICS_ variable. A variable that is
 // set to the empty string and one that is not set at all are

internal/config/export_test.go

@@ -6,21 +6,6 @@ import "log/slog"
 // the external config_test package so each helper can be covered by
 // its own table-driven test without weakening the package API.
 
-// WarnSharedRateLimitBucketForTest loads a Config from the current
-// environment and emits its startup warnings to log. The real logger
-// writes to stdout, so this lets the warning's firing condition be
-// asserted against a handler the test controls.
-func WarnSharedRateLimitBucketForTest(log *slog.Logger) error {
-	c, err := loadFromEnv()
-	if err != nil {
-		return err
-	}
-
-	c.warnSharedRateLimitBucket(log)
-
-	return nil
-}
-
 // WarnEgressAllowlistForTest loads a Config from the current
 // environment and emits its egress-allowlist startup warning to
 // log, so a test can assert both that the warning fires only when

internal/database/model_event.go

@@ -31,6 +31,11 @@ type Event struct {
 	Body        string `gorm:"type:text"   json:"body"`
 	ContentType string `json:"contentType"`
 
+	// BodyBytes is the size of Body in bytes, recorded when the event
+	// is stored so the recent events list can show it without reading
+	// the body.
+	BodyBytes int64 `gorm:"not null" json:"bodyBytes"`
+
 	// ResubmittedFromID names the event this one was copied from by
 	// an operator resubmit. It is nil for an event that arrived on
 	// the receiver, which is every event created before the column

internal/database/model_user.go

@@ -1,13 +1,58 @@
 package database
 
+import (
+	"errors"
+	"fmt"
+
+	"gorm.io/gorm"
+)
+
+// MaxUsernameBytes is the longest username, in bytes, that a user may
+// have. The same number appears in the check constraint on
+// User.Username, because a struct tag cannot reference a constant.
+//
+// A login stores the username in the session cookie, and both
+// securecookie and browsers refuse a cookie value past about 4096
+// bytes. That value is the session base64-encoded twice, so it holds
+// 4096 × 3/4 × 3/4 = 2304 bytes of session, and the signature,
+// timestamp and the session's other values take about 270 of those: a
+// username longer than about 2030 bytes can never log in. The limit is
+// about half that, so the session can carry more values later without
+// locking out an account whose username is already at the limit.
+const MaxUsernameBytes = 1024
+
+// ErrUsernameTooLong is returned when a user is saved with a username
+// longer than MaxUsernameBytes.
+var ErrUsernameTooLong = errors.New("username is too long")
+
 // User represents a user of the webhooker service
+//
+//nolint:lll // a struct tag cannot wrap
 type User struct {
 	BaseModel
 
-	Username string `gorm:"uniqueIndex;not null" json:"username"`
+	Username string `gorm:"uniqueIndex;not null;check:length(CAST(username AS BLOB)) <= 1024" json:"username"`
 	Password string `gorm:"not null"                                                          json:"-"` // Argon2 hashed
 
 	// Relations
 	Webhooks []Webhook `json:"webhooks,omitempty"`
 	APIKeys  []APIKey  `json:"apiKeys,omitempty"`
 }
+
+// BeforeSave rejects a username longer than MaxUsernameBytes when a whole
+// User is created or saved, so those calls get ErrUsernameTooLong rather
+// than the database's constraint error. A column update such as
+// Update("username", ...) is caught only by the check constraint, as is
+// any path that writes the table without this model.
+func (u *User) BeforeSave(_ *gorm.DB) error {
+	if len(u.Username) > MaxUsernameBytes {
+		return fmt.Errorf(
+			"%w: %d bytes, limit is %d",
+			ErrUsernameTooLong,
+			len(u.Username),
+			MaxUsernameBytes,
+		)
+	}
+
+	return nil
+}

internal/database/model_user_test.go

@@ -0,0 +1,65 @@
+package database_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// usernameAtLimit is exactly MaxUsernameBytes long, built from a
+// two-byte character. A check that counted characters rather than bytes
+// would see half the length and let the one-byte-longer name through.
+func usernameAtLimit() string {
+	return strings.Repeat("é", database.MaxUsernameBytes/2)
+}
+
+func TestUserCreate_RejectsOverlongUsername(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	err := db.Create(&database.User{
+		Username: usernameAtLimit() + "x",
+		Password: "hash",
+	}).Error
+
+	require.ErrorIs(t, err, database.ErrUsernameTooLong)
+}
+
+func TestUserCreate_AcceptsUsernameAtLimit(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	require.NoError(t, db.Create(&database.User{
+		Username: usernameAtLimit(),
+		Password: "hash",
+	}).Error)
+}
+
+// TestUsersTable_EnforcesUsernameLimitWithoutTheModel inserts with raw
+// SQL, as a path that bypassed User.BeforeSave would, so only the
+// table's check constraint stands between it and an over-long
+// username. Accepting the name at the limit and refusing the next byte
+// also pins the constraint's number to MaxUsernameBytes.
+func TestUsersTable_EnforcesUsernameLimitWithoutTheModel(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	insert := "INSERT INTO users (id, username, password) VALUES (?, ?, ?)"
+
+	require.NoError(t, db.Exec(
+		insert, uuid.New().String(), usernameAtLimit(), "hash",
+	).Error)
+
+	err := db.Exec(
+		insert, uuid.New().String(), usernameAtLimit()+"x", "hash",
+	).Error
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "CHECK constraint failed")
+}

internal/delivery/ssrf.go

@@ -43,6 +43,13 @@ var (
 // 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.
+//
 //nolint:gochecknoglobals // package-level network list is appropriate here
 var blockedNetworks []*net.IPNet
 

internal/handlers/auth.go

@@ -36,7 +36,7 @@ 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
 		}
@@ -103,9 +103,10 @@ func (h *Handlers) renderLoginError(
 // The credential check runs BEFORE any rate-limit budget is
 // consulted, and only a failed check spends budget. That is what
 // keeps the single administrative path reachable: behind the reverse
-// proxy this deployment requires, with TRUSTED_PROXIES unset, every
-// client shares one bucket, so a limiter spent on arrival lets any
-// stranger deny the operator's own correct password indefinitely.
+// proxy this deployment requires, when TRUSTED_PROXIES does not cover
+// it, every client shares one bucket, so a limiter spent on arrival
+// lets any stranger deny the operator's own correct password
+// indefinitely.
 //
 // Verifying first means every login POST costs an Argon2id hash, so
 // the work is taken under a bounded number of verification slots.
@@ -165,11 +166,7 @@ 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
 	}
@@ -241,24 +238,14 @@ 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
 	}
@@ -267,11 +254,7 @@ 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
 	}

internal/handlers/auth_test.go

@@ -25,7 +25,7 @@ const (
 
 	// sharedProxyPeer is the whole point of this file. Production is
 	// required to run behind a TLS-terminating reverse proxy, and
-	// TRUSTED_PROXIES defaults to empty, so every client — attacker
+	// when TRUSTED_PROXIES does not cover it every client — attacker
 	// and operator alike — reaches the process from the proxy's
 	// address and shares one rate-limit bucket. Both parties in
 	// these tests therefore use the same RemoteAddr.
@@ -115,11 +115,11 @@ func floodFailures(
 // done-criterion of https://git.eeqj.de/sneak/webhooker/issues/150.
 //
 // The attacker and the operator share one rate-limit bucket, because
-// behind the mandated reverse proxy with TRUSTED_PROXIES unset every
-// client keys on the proxy's address. The attacker floods the
-// operator's own username — a single-admin product has a predictable
-// one — far past the failure limit. The operator must still be able
-// to log in with the correct password.
+// behind the mandated reverse proxy, when TRUSTED_PROXIES does not
+// cover it, every client keys on the proxy's address. The attacker
+// floods the operator's own username — a single-admin product has a
+// predictable one — far past the failure limit. The operator must
+// still be able to log in with the correct password.
 //
 // This fails if credentials stop being verified ahead of the limiter.
 func TestLogin_StrangersFloodCannotLockOutTheOperator(t *testing.T) {
@@ -453,3 +453,33 @@ func TestLogin_SuccessCreatesSession(t *testing.T) {
 		"the issued cookie must carry an authenticated session",
 	)
 }
+
+// TestLogin_UsernameAtLimitCanLogIn shows that a username of exactly
+// database.MaxUsernameBytes still fits in the session cookie. Past
+// what the cookie can carry, a correct login answers 500.
+func TestLogin_UsernameAtLimitCanLogIn(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h  *handlers.Handlers
+		db *database.Database
+	)
+
+	app := newTestApp(t, &h, &db)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	username := strings.Repeat("a", database.MaxUsernameBytes)
+
+	hash, err := database.HashPassword(operatorPassword)
+	require.NoError(t, err)
+	require.NoError(t, db.DB().Create(&database.User{
+		Username: username,
+		Password: hash,
+	}).Error)
+
+	w := submitLogin(h, sharedProxyPeer, username, operatorPassword)
+
+	assert.Equal(t, http.StatusSeeOther, w.Code)
+}

internal/handlers/delivery_replay.go

@@ -105,9 +105,7 @@ 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 +122,14 @@ 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
 	}
@@ -173,7 +171,7 @@ 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
 	}
@@ -195,7 +193,7 @@ 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
@@ -212,7 +210,7 @@ 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 +220,7 @@ 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

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

@@ -99,7 +99,7 @@ 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 +120,20 @@ 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 +147,7 @@ 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 +155,7 @@ 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 +207,7 @@ 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 +225,7 @@ 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
 	}

internal/handlers/event_resubmit_test.go

@@ -204,6 +204,7 @@ func assertEventCopy(
 	assert.Equal(t, original.Method, fresh.Method)
 	assert.Equal(t, original.Headers, fresh.Headers)
 	assert.Equal(t, original.Body, fresh.Body)
+	assert.Equal(t, int64(len(original.Body)), fresh.BodyBytes)
 	assert.Equal(t, original.ContentType, fresh.ContentType)
 	assert.Equal(t, original.EntrypointID, fresh.EntrypointID)
 	assert.Equal(t, original.WebhookID, fresh.WebhookID)

internal/handlers/export_test.go

@@ -1,9 +1,11 @@
 package handlers
 
 import (
+	"context"
 	"html/template"
 	"log/slog"
 	"net/http"
+	"net/http/httptest"
 
 	"sneak.berlin/go/webhooker/internal/database"
 )
@@ -63,12 +65,20 @@ func (s *Handlers) LoadEventLogViewsForTest(
 	page int,
 ) []EventLogView {
 	views, _, _ := s.loadEventsWithDeliveries(
-		w, webhook, nil, page,
+		w, newRequestForTest(), webhook, nil, page,
 	)
 
 	return views
 }
 
+// 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.
@@ -122,5 +132,5 @@ 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

@@ -28,7 +28,7 @@ const (
 	// maxBodyShift is the bit shift for 1 MB body limit.
 	maxBodyShift = 20
 	// recentEventLimit is the number of recent events to show.
-	recentEventLimit = 20
+	recentEventLimit = 50
 	// paginationPerPage is the number of items per page.
 	paginationPerPage = 25
 
@@ -135,6 +135,7 @@ 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{
@@ -146,6 +147,15 @@ 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 and
+// the CSRF middleware for a refused form.
+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,
@@ -163,15 +173,76 @@ 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")
+
+	data := s.pageData(r, map[string]any{
+		"Status":     status,
+		"StatusText": http.StatusText(status),
+		"Message":    errorPageText(status),
+	})
+
+	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
@@ -224,14 +295,17 @@ 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))
+}
+
+// pageData adds the fields the shared layout renders to a page's own
+// data.
+func (s *Handlers) pageData(r *http.Request, data any) any {
 	userInfo := s.getUserInfo(r)
 	csrfToken := middleware.CSRFToken(r)
 
@@ -245,19 +319,16 @@ func (s *Handlers) renderTemplate(
 		m["User"] = userInfo
 		m["CSRFToken"] = csrfToken
 		m["Version"] = version
-		s.executeTemplate(w, tmpl, m)
 
-		return
+		return m
 	}
 
-	wrapper := templateDataWrapper{
+	return templateDataWrapper{
 		User:      userInfo,
 		CSRFToken: csrfToken,
 		Version:   version,
 		Data:      data,
 	}
-
-	s.executeTemplate(w, tmpl, wrapper)
 }
 
 // executeTemplate renders the template into a buffer and writes to
@@ -270,6 +341,7 @@ func (s *Handlers) renderTemplate(
 // this reason.
 func (s *Handlers) executeTemplate(
 	w http.ResponseWriter,
+	r *http.Request,
 	tmpl *template.Template,
 	data any,
 ) {
@@ -280,10 +352,7 @@ 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

@@ -307,10 +307,14 @@ 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/logbound_test.go

@@ -339,11 +339,9 @@ const storedUserPassword = "correct-horse-battery-staple"
 // storedFillBytes is the raw length of the client-chosen value in
 // those accounts' usernames. It is well past the 512-byte field
 // budget, so the line is still truncated, but short enough that the
-// session cookie a successful login writes stays inside
-// securecookie's 4 KB limit: the cookie is written BEFORE the
-// "user logged in" line, so an 8 KB username answers 500 and never
-// reaches it.
-const storedFillBytes = 1024
+// whole username, markers and fill name included, stays within
+// database.MaxUsernameBytes.
+const storedFillBytes = 960
 
 // storedFill builds a username fill of storedFillBytes raw bytes out
 // of repetitions of ch, with both markers at its far end.

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

@@ -88,6 +88,8 @@ func TestHandleProfile_OwnProfile_OK(t *testing.T) {
 	h.HandleProfile().ServeHTTP(w, req)
 
 	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Contains(t, w.Body.String(), "Account Information")
+	assert.NotContains(t, w.Body.String(), "Account Type")
 }
 
 func TestHandleProfile_OtherProfile_Forbidden(t *testing.T) {
@@ -126,7 +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)
@@ -137,7 +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/recent_events.go

@@ -0,0 +1,293 @@
+package handlers
+
+import (
+	"net/http"
+	"slices"
+	"strconv"
+	"time"
+
+	"github.com/dustin/go-humanize"
+	"gorm.io/gorm"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// recentEventColumns is the recent events list's projection. It
+// leaves out the body, for the reason maxRenderedBodyBytes gives,
+// and reads its size from body_bytes, recorded when the event was
+// stored.
+const recentEventColumns = "id, created_at, method, content_type, " +
+	"resubmitted_from_id, body_bytes"
+
+// recentAttemptColumns is the part of a recorded attempt the list
+// uses. The event log's deliveryResultColumns also reads response
+// bodies, which the list does not show.
+const recentAttemptColumns = "delivery_id, status_code, created_at"
+
+// RecentEventView is one row of the recent events list on a
+// webhook's page.
+type RecentEventView struct {
+	Method      string
+	ContentType string
+
+	// ResubmittedFromID names the event this one was copied from,
+	// empty for an event that arrived on the receiver.
+	ResubmittedFromID string
+
+	// Received is how long ago the event arrived, and ReceivedUTC
+	// the full timestamp the page shows on hover.
+	Received    string
+	ReceivedUTC string
+
+	// Size is the size of the stored body.
+	Size string
+
+	// ProcessingTime is how long the event's slowest delivery
+	// took; see processingTime.
+	ProcessingTime string
+
+	// Status is what the webhook's HTTP target answered, and
+	// StatusClass its colour; see targetStatus. Both are empty
+	// unless the webhook has exactly one HTTP target.
+	Status      string
+	StatusClass string
+}
+
+// recentEventRow is one row of recentEventColumns.
+type recentEventRow struct {
+	ID                string
+	CreatedAt         time.Time
+	Method            string
+	ContentType       string
+	ResubmittedFromID *string
+	BodyBytes         uint64
+}
+
+// recentAttemptRow is one row of recentAttemptColumns. CreatedAt is
+// when the attempt's result was recorded, which is when the attempt
+// finished.
+type recentAttemptRow struct {
+	DeliveryID string
+	StatusCode int
+	CreatedAt  time.Time
+}
+
+// singleHTTPTargetID returns the ID of the webhook's HTTP target
+// when it has exactly one, and "" when it has none or several.
+func singleHTTPTargetID(targets []database.Target) string {
+	id := ""
+	count := 0
+
+	for i := range targets {
+		if targets[i].Type == database.TargetTypeHTTP {
+			id = targets[i].ID
+			count++
+		}
+	}
+
+	if count != 1 {
+		return ""
+	}
+
+	return id
+}
+
+// loadRecentEvents loads the webhook's recentEventLimit newest
+// events for its page, newest first. statusTargetID is the
+// webhook's only HTTP target, or "" when the list shows no status.
+func loadRecentEvents(
+	webhookDB *gorm.DB, webhookID, statusTargetID string,
+) ([]RecentEventView, error) {
+	var rows []recentEventRow
+
+	err := webhookDB.Model(&database.Event{}).
+		Select(recentEventColumns).
+		Where("webhook_id = ?", webhookID).
+		Order("created_at DESC").
+		Limit(recentEventLimit).
+		Find(&rows).Error
+	if err != nil {
+		return nil, err
+	}
+
+	eventIDs := make([]string, len(rows))
+	for i := range rows {
+		eventIDs[i] = rows[i].ID
+	}
+
+	// Oldest first, so an event's last delivery to a target is its
+	// newest: a replay adds a delivery rather than changing the
+	// earlier one.
+	var deliveries []database.Delivery
+
+	err = webhookDB.
+		Select("id, event_id, target_id, status, created_at").
+		Where("event_id IN ?", eventIDs).
+		Order("created_at ASC").
+		Find(&deliveries).Error
+	if err != nil {
+		return nil, err
+	}
+
+	byEvent := make(map[string][]database.Delivery, len(rows))
+	deliveryIDs := make([]string, len(deliveries))
+
+	for i := range deliveries {
+		eventID := deliveries[i].EventID
+		byEvent[eventID] = append(byEvent[eventID], deliveries[i])
+		deliveryIDs[i] = deliveries[i].ID
+	}
+
+	attempts, err := loadRecentAttempts(webhookDB, deliveryIDs)
+	if err != nil {
+		return nil, err
+	}
+
+	views := make([]RecentEventView, len(rows))
+	for i := range rows {
+		views[i] = rows[i].view(
+			byEvent[rows[i].ID], attempts, statusTargetID,
+		)
+	}
+
+	return views, nil
+}
+
+// loadRecentAttempts loads the recorded attempts of the listed
+// events' deliveries, keyed by delivery ID, each delivery's in
+// attempt order. The IDs go in chunks for the reason
+// deliveryIDChunkSize gives.
+func loadRecentAttempts(
+	webhookDB *gorm.DB, deliveryIDs []string,
+) (map[string][]recentAttemptRow, error) {
+	byDelivery := make(map[string][]recentAttemptRow)
+
+	for chunk := range slices.Chunk(deliveryIDs, deliveryIDChunkSize) {
+		var rows []recentAttemptRow
+
+		err := webhookDB.Model(&database.DeliveryResult{}).
+			Select(recentAttemptColumns).
+			Where("delivery_id IN ?", chunk).
+			Order("attempt_num ASC").
+			Find(&rows).Error
+		if err != nil {
+			return nil, err
+		}
+
+		for i := range rows {
+			id := rows[i].DeliveryID
+			byDelivery[id] = append(byDelivery[id], rows[i])
+		}
+	}
+
+	return byDelivery, nil
+}
+
+// view projects a loaded row for rendering. deliveries is the
+// event's deliveries, oldest first, and attempts their recorded
+// attempts keyed by delivery ID.
+func (r *recentEventRow) view(
+	deliveries []database.Delivery,
+	attempts map[string][]recentAttemptRow,
+	statusTargetID string,
+) RecentEventView {
+	v := RecentEventView{
+		Method:         r.Method,
+		ContentType:    r.ContentType,
+		Received:       humanize.Time(r.CreatedAt),
+		ReceivedUTC:    r.CreatedAt.UTC().Format(time.DateTime) + " UTC",
+		Size:           humanize.Bytes(r.BodyBytes),
+		ProcessingTime: processingTime(deliveries, attempts),
+	}
+
+	if r.ResubmittedFromID != nil {
+		v.ResubmittedFromID = *r.ResubmittedFromID
+	}
+
+	if statusTargetID != "" {
+		v.Status, v.StatusClass = targetStatus(
+			deliveries, attempts, statusTargetID,
+		)
+	}
+
+	return v
+}
+
+// processingTime is how long the event's slowest delivery took,
+// from being queued to its last recorded attempt, time spent
+// waiting between retries included. A delivery is queued when its
+// event is received, or when an operator replays it, so a replay
+// is timed from the replay rather than from the event's arrival.
+// It is "in progress" while any delivery is pending or retrying,
+// and empty for an event with no deliveries.
+func processingTime(
+	deliveries []database.Delivery,
+	attempts map[string][]recentAttemptRow,
+) string {
+	if len(deliveries) == 0 {
+		return ""
+	}
+
+	var slowest time.Duration
+
+	for i := range deliveries {
+		if !deliveries[i].Status.Terminal() {
+			return "in progress"
+		}
+
+		tries := attempts[deliveries[i].ID]
+		if len(tries) == 0 {
+			continue
+		}
+
+		last := tries[len(tries)-1].CreatedAt
+		slowest = max(slowest, last.Sub(deliveries[i].CreatedAt))
+	}
+
+	return slowest.Round(time.Millisecond).String()
+}
+
+// targetStatus is what the target answered for the event, and the
+// colour to show it in: the HTTP status code of the last attempt of
+// the event's newest delivery to the target. Without a code it is
+// "no response" when that attempt failed before a response
+// arrived, the delivery's status ("pending") before any attempt,
+// and "not sent" when the event has no delivery to the target.
+func targetStatus(
+	deliveries []database.Delivery,
+	attempts map[string][]recentAttemptRow,
+	targetID string,
+) (string, string) {
+	newest := -1
+
+	for i := range deliveries {
+		if deliveries[i].TargetID == targetID {
+			newest = i
+		}
+	}
+
+	if newest < 0 {
+		return "not sent", "text-gray-400"
+	}
+
+	tries := attempts[deliveries[newest].ID]
+	if len(tries) == 0 {
+		return string(deliveries[newest].Status), "text-gray-400"
+	}
+
+	code := tries[len(tries)-1].StatusCode
+
+	switch {
+	case code == 0:
+		return "no response", "text-red-600"
+	case code >= http.StatusInternalServerError:
+		return strconv.Itoa(code), "text-red-600"
+	case code >= http.StatusBadRequest:
+		return strconv.Itoa(code), "text-yellow-600"
+	case code >= http.StatusMultipleChoices:
+		return strconv.Itoa(code), "text-gray-500"
+	case code >= http.StatusOK:
+		return strconv.Itoa(code), "text-green-600"
+	default:
+		return strconv.Itoa(code), "text-gray-500"
+	}
+}

internal/handlers/recent_events_test.go

@@ -0,0 +1,362 @@
+package handlers_test
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/go-chi/chi"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+// statusTitle marks the status column's cell in a recent events
+// row; it is absent from the page when the column is not shown.
+const statusTitle = `title="HTTP status from the HTTP target"`
+
+// recentEventsFixture is one started app and a webhook whose
+// recent events list a test fills.
+type recentEventsFixture struct {
+	h         *handlers.Handlers
+	sess      *session.Session
+	db        *database.Database
+	webhook   *database.Webhook
+	webhookDB *gorm.DB
+}
+
+func newRecentEventsFixture(t *testing.T) *recentEventsFixture {
+	t.Helper()
+
+	f := &recentEventsFixture{}
+
+	var dbMgr *database.WebhookDBManager
+
+	app := newTestApp(t, &f.h, &f.sess, &f.db, &dbMgr)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	f.webhook = seedWebhook(t, f.db)
+
+	webhookDB, err := dbMgr.GetDB(f.webhook.ID)
+	require.NoError(t, err)
+
+	f.webhookDB = webhookDB
+
+	return f
+}
+
+func (f *recentEventsFixture) render(t *testing.T) string {
+	t.Helper()
+
+	return renderSourceDetailPage(t, f.h, f.sess, f.webhook.ID)
+}
+
+// event records an event received at receivedAt, with its body's
+// size as the receiver records it.
+func (f *recentEventsFixture) event(
+	t *testing.T, contentType, body string, receivedAt time.Time,
+) *database.Event {
+	t.Helper()
+
+	event := &database.Event{
+		WebhookID:   f.webhook.ID,
+		Method:      http.MethodPost,
+		Body:        body,
+		BodyBytes:   int64(len(body)),
+		ContentType: contentType,
+	}
+	event.CreatedAt = receivedAt
+
+	require.NoError(t, f.webhookDB.Omit(
+		clause.Associations,
+	).Create(event).Error)
+
+	return event
+}
+
+// delivery records a delivery of the event to the target, queued
+// when the event was received.
+func (f *recentEventsFixture) delivery(
+	t *testing.T,
+	event *database.Event,
+	targetID string,
+	status database.DeliveryStatus,
+) *database.Delivery {
+	t.Helper()
+
+	return f.deliveryQueuedAt(
+		t, event, targetID, status, event.CreatedAt,
+	)
+}
+
+// deliveryQueuedAt records a delivery of the event to the target,
+// queued at queuedAt, as a replay is.
+func (f *recentEventsFixture) deliveryQueuedAt(
+	t *testing.T,
+	event *database.Event,
+	targetID string,
+	status database.DeliveryStatus,
+	queuedAt time.Time,
+) *database.Delivery {
+	t.Helper()
+
+	dlv := &database.Delivery{
+		EventID:  event.ID,
+		TargetID: targetID,
+		Status:   status,
+	}
+	dlv.CreatedAt = queuedAt
+
+	require.NoError(t, f.webhookDB.Omit(
+		clause.Associations,
+	).Create(dlv).Error)
+
+	return dlv
+}
+
+// attempt records one attempt of the delivery that finished took
+// after the delivery was queued, with HTTP status code (0 for no
+// response).
+func (f *recentEventsFixture) attempt(
+	t *testing.T, dlv *database.Delivery, code int, took time.Duration,
+) {
+	t.Helper()
+
+	result := &database.DeliveryResult{
+		DeliveryID: dlv.ID,
+		AttemptNum: 1,
+		StatusCode: code,
+	}
+	result.CreatedAt = dlv.CreatedAt.Add(took)
+
+	require.NoError(t, f.webhookDB.Omit(
+		clause.Associations,
+	).Create(result).Error)
+}
+
+// statusCell is the status column's cell as the page renders it.
+func statusCell(class, text string) string {
+	return `<span class="font-medium ` + class + `" ` + statusTitle +
+		`>` + text + `</span>`
+}
+
+// TestHandleSourceDetail_ShowsFiftyNewestEvents proves the list is
+// headed "50 Most Recent Events" and holds the 50 newest events,
+// newest first, and not one more.
+func TestHandleSourceDetail_ShowsFiftyNewestEvents(t *testing.T) {
+	t.Parallel()
+
+	f := newRecentEventsFixture(t)
+	base := time.Now().Add(-time.Hour)
+
+	for i := range 51 {
+		f.event(
+			t, fmt.Sprintf("application/x-recent-%02d", i), "{}",
+			base.Add(time.Duration(i)*time.Second),
+		)
+	}
+
+	body := f.render(t)
+
+	assert.Contains(t, body, ">50 Most Recent Events</h2>")
+	assert.Equal(t, 50, strings.Count(body, `title="Body size"`))
+	assert.NotContains(t, body, "application/x-recent-00")
+	assert.Contains(t, body, "application/x-recent-01")
+	assert.Less(
+		t,
+		strings.Index(body, "application/x-recent-50"),
+		strings.Index(body, "application/x-recent-49"),
+	)
+}
+
+// TestHandleSourceDetail_RecentEventColumns proves a row shows its
+// time relative with the UTC timestamp on hover, its body size,
+// and its processing time once every delivery has finished.
+func TestHandleSourceDetail_RecentEventColumns(t *testing.T) {
+	t.Parallel()
+
+	f := newRecentEventsFixture(t)
+	logTarget := seedTarget(t, f.db, f.webhook.ID, database.TargetTypeLog)
+
+	receivedAt := time.Now().Add(-210 * time.Second).
+		UTC().Truncate(time.Second)
+
+	done := f.event(
+		t, contentTypeJSON, strings.Repeat("x", 2048), receivedAt,
+	)
+	f.attempt(
+		t,
+		f.delivery(t, done, logTarget.ID, database.DeliveryStatusDelivered),
+		0, 1500*time.Millisecond,
+	)
+
+	waiting := f.event(t, "text/plain", "{}", receivedAt)
+	f.delivery(t, waiting, logTarget.ID, database.DeliveryStatusPending)
+
+	body := f.render(t)
+
+	assert.Contains(
+		t, body,
+		`<span title="`+receivedAt.Format(time.DateTime)+
+			` UTC">3 minutes ago</span>`,
+	)
+	assert.Contains(t, body, `<span title="Body size">2.0 kB</span>`)
+	assert.Contains(t, body, ">1.5s</span>")
+	assert.Contains(t, body, ">in progress</span>")
+}
+
+// TestHandleSourceDetail_StatusWithSingleHTTPTarget proves that a
+// webhook with exactly one HTTP target shows, colour-coded, what
+// that target answered for each event. The log target beside it
+// does not count against "exactly one".
+func TestHandleSourceDetail_StatusWithSingleHTTPTarget(t *testing.T) {
+	t.Parallel()
+
+	f := newRecentEventsFixture(t)
+	target := seedTarget(t, f.db, f.webhook.ID, database.TargetTypeHTTP)
+	seedTarget(t, f.db, f.webhook.ID, database.TargetTypeLog)
+
+	now := time.Now()
+
+	for _, code := range []int{204, 302, 404, 503, 0} {
+		dlv := f.delivery(
+			t, f.event(t, contentTypeJSON, "{}", now), target.ID,
+			database.DeliveryStatusDelivered,
+		)
+		f.attempt(t, dlv, code, time.Second)
+	}
+
+	f.delivery(
+		t, f.event(t, contentTypeJSON, "{}", now), target.ID,
+		database.DeliveryStatusPending,
+	)
+	f.event(t, contentTypeJSON, "{}", now)
+
+	// A replay is a newer delivery, and its answer is the one shown.
+	replayed := f.event(t, contentTypeJSON, "{}", now)
+	f.attempt(t, f.delivery(
+		t, replayed, target.ID, database.DeliveryStatusFailed,
+	), 502, time.Second)
+	f.attempt(t, f.deliveryQueuedAt(
+		t, replayed, target.ID, database.DeliveryStatusDelivered,
+		now.Add(time.Minute),
+	), 200, time.Second)
+
+	body := f.render(t)
+
+	assert.Contains(t, body, statusCell("text-green-600", "204"))
+	assert.Contains(t, body, statusCell("text-gray-500", "302"))
+	assert.Contains(t, body, statusCell("text-yellow-600", "404"))
+	assert.Contains(t, body, statusCell("text-red-600", "503"))
+	assert.Contains(t, body, statusCell("text-red-600", "no response"))
+	assert.Contains(t, body, statusCell("text-gray-400", "pending"))
+	assert.Contains(t, body, statusCell("text-gray-400", "not sent"))
+	assert.Contains(t, body, statusCell("text-green-600", "200"))
+	assert.NotContains(t, body, ">502<")
+}
+
+// TestHandleSourceDetail_NoStatusWithoutSingleHTTPTarget proves the
+// status column is absent when the webhook has no HTTP target or
+// more than one.
+func TestHandleSourceDetail_NoStatusWithoutSingleHTTPTarget(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	cases := map[string][]database.TargetType{
+		"none":    {database.TargetTypeLog},
+		"several": {database.TargetTypeHTTP, database.TargetTypeHTTP},
+	}
+
+	for name, types := range cases {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			f := newRecentEventsFixture(t)
+			event := f.event(t, contentTypeJSON, "{}", time.Now())
+
+			for _, tt := range types {
+				target := seedTarget(t, f.db, f.webhook.ID, tt)
+				f.attempt(t, f.delivery(
+					t, event, target.ID,
+					database.DeliveryStatusDelivered,
+				), 200, time.Second)
+			}
+
+			body := f.render(t)
+
+			assert.Contains(t, body, `title="Body size"`)
+			assert.NotContains(t, body, statusTitle)
+		})
+	}
+}
+
+// TestHandleWebhook_RecordsBodySize proves the receiver records the
+// body's size in bytes, not characters, with the event it stores.
+func TestHandleWebhook_RecordsBodySize(t *testing.T) {
+	t.Parallel()
+
+	f := newRecentEventsFixture(t)
+	seedEntrypoint(t, f.db, f.webhook.ID)
+
+	// Two bytes per character.
+	body := strings.Repeat("é", 1024)
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodPost, "/webhook/x",
+		strings.NewReader(body),
+	)
+
+	rctx := chi.NewRouteContext()
+	rctx.URLParams.Add("uuid", "ep-"+f.webhook.ID)
+
+	req = req.WithContext(context.WithValue(
+		req.Context(), chi.RouteCtxKey, rctx,
+	))
+
+	w := httptest.NewRecorder()
+	f.h.HandleWebhook().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusOK, w.Code)
+
+	var stored database.Event
+
+	require.NoError(t, f.webhookDB.First(&stored).Error)
+	assert.Equal(t, int64(2048), stored.BodyBytes)
+}
+
+// TestHandleSourceDetail_FailedLoadIsAnError proves that when the
+// list cannot be loaded the page answers with an error, rather than
+// an empty list claiming the webhook has no events.
+func TestHandleSourceDetail_FailedLoadIsAnError(t *testing.T) {
+	t.Parallel()
+
+	f := newRecentEventsFixture(t)
+	target := seedTarget(t, f.db, f.webhook.ID, database.TargetTypeHTTP)
+
+	f.attempt(t, f.delivery(
+		t, f.event(t, contentTypeJSON, "{}", time.Now()), target.ID,
+		database.DeliveryStatusDelivered,
+	), 200, time.Second)
+
+	// The attempts are the list's last query, so its events and
+	// deliveries have already loaded when it fails.
+	require.NoError(t, f.webhookDB.Exec(
+		"DROP TABLE delivery_results",
+	).Error)
+
+	w := serveSourceDetailPage(t, f.h, f.sess, f.webhook.ID)
+
+	assert.Equal(t, http.StatusInternalServerError, w.Code)
+	assert.NotContains(t, w.Body.String(), "No events received yet.")
+}

internal/handlers/source_detail_test.go

@@ -62,6 +62,23 @@ func renderSourceDetailPage(
 ) string {
 	t.Helper()
 
+	w := serveSourceDetailPage(t, h, sess, webhookID)
+
+	require.Equal(t, http.StatusOK, w.Code)
+
+	return w.Body.String()
+}
+
+// serveSourceDetailPage runs the real source detail handler for a
+// webhook and returns its response, whatever its status.
+func serveSourceDetailPage(
+	t *testing.T,
+	h *handlers.Handlers,
+	sess *session.Session,
+	webhookID string,
+) *httptest.ResponseRecorder {
+	t.Helper()
+
 	req := httptest.NewRequestWithContext(
 		context.Background(),
 		http.MethodGet,
@@ -87,9 +104,7 @@ func renderSourceDetailPage(
 	w := httptest.NewRecorder()
 	h.HandleSourceDetail().ServeHTTP(w, req)
 
-	require.Equal(t, http.StatusOK, w.Code)
-
-	return w.Body.String()
+	return w
 }
 
 // TestHandleSourceDetail_MasksSlackWebhookURL is the

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
 	}
@@ -388,7 +380,7 @@ 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
 		}
@@ -415,16 +407,23 @@ func (h *Handlers) renderSourceDetail(
 		"webhook_id = ?", webhook.ID,
 	).Find(&targets)
 
-	var events []database.Event
+	var events []RecentEventView
 
 	if h.dbMgr.DBExists(webhook.ID) {
-		webhookDB, dbErr := h.dbMgr.GetDB(webhook.ID)
-		if dbErr == nil {
-			webhookDB.Where(
-				"webhook_id = ?", webhook.ID,
-			).Order("created_at DESC").Limit(
-				recentEventLimit,
-			).Find(&events)
+		webhookDB, err := h.dbMgr.GetDB(webhook.ID)
+		if err != nil {
+			h.serverError(w, r, "failed to get webhook database", err)
+
+			return
+		}
+
+		events, err = loadRecentEvents(
+			webhookDB, webhook.ID, singleHTTPTargetID(targets),
+		)
+		if err != nil {
+			h.serverError(w, r, "failed to load recent events", err)
+
+			return
 		}
 	}
 
@@ -475,7 +474,7 @@ 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
 		}
@@ -510,7 +509,7 @@ 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
 		}
@@ -519,9 +518,7 @@ 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
 		}
@@ -575,7 +572,7 @@ func (h *Handlers) applyWebhookEdit(
 
 	err := h.db.DB().Save(webhook).Error
 	if err != nil {
-		h.serverError(w, "failed to update webhook", err)
+		h.serverError(w, r, "failed to update webhook", err)
 
 		return
 	}
@@ -605,7 +602,7 @@ 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
 		}
@@ -632,7 +629,7 @@ 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
 	}
@@ -658,7 +655,7 @@ 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
@@ -802,7 +799,7 @@ 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
 	}
@@ -824,7 +821,7 @@ 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
 		}
@@ -832,7 +829,7 @@ 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
@@ -942,6 +939,7 @@ 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,
@@ -955,7 +953,7 @@ 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
@@ -992,7 +990,7 @@ 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
@@ -1001,7 +999,7 @@ 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
@@ -1224,7 +1222,7 @@ 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
 		}
@@ -1233,9 +1231,7 @@ 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
 		}
@@ -1251,7 +1247,7 @@ 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
 		}
@@ -1282,7 +1278,7 @@ 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
 		}
@@ -1291,9 +1287,7 @@ 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
 		}
@@ -1364,7 +1358,7 @@ 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
 	}
@@ -1458,7 +1452,7 @@ 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:
@@ -1508,7 +1502,7 @@ 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,
@@ -1530,7 +1524,7 @@ func (h *Handlers) buildSlackTargetConfig(
 		return "", err
 	}
 
-	return marshalTargetConfig(w, delivery.SlackTargetConfig{
+	return h.marshalTargetConfig(w, r, delivery.SlackTargetConfig{
 		WebhookURL: targetURL,
 	})
 }
@@ -1584,16 +1578,14 @@ 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
 	}
@@ -1609,6 +1601,7 @@ 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)
@@ -1627,8 +1620,8 @@ func (h *Handlers) buildDatabaseTargetConfig(
 		return "", err
 	}
 
-	return marshalTargetConfig(
-		w, map[string]any{"expiry": expiry},
+	return h.marshalTargetConfig(
+		w, r, map[string]any{"expiry": expiry},
 	)
 }
 
@@ -1682,7 +1675,7 @@ 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
 		}
@@ -1692,11 +1685,7 @@ 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
 		}
@@ -1786,18 +1775,14 @@ 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)
 		if err != nil {
-			h.log.Error(errMsg, "error", err)
-			http.Error(
-				w, "Internal server error",
-				http.StatusInternalServerError,
-			)
+			h.serverError(w, r, errMsg, err)
 
 			return
 		}

internal/handlers/target_edit.go

@@ -88,9 +88,7 @@ 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
 		}
@@ -157,7 +155,7 @@ func (h *Handlers) applyTargetEdit(
 
 	err = h.db.DB().Save(target).Error
 	if err != nil {
-		h.serverError(w, "failed to update target", err)
+		h.serverError(w, r, "failed to update target", err)
 
 		return
 	}
@@ -220,7 +218,7 @@ 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/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
@@ -230,6 +243,7 @@ func (s eventSource) event() *database.Event {
 		Method:            s.Method,
 		Headers:           s.HeadersJSON,
 		Body:              string(s.Body),
+		BodyBytes:         int64(len(s.Body)),
 		ContentType:       s.ContentType,
 		ResubmittedFromID: s.ResubmittedFromID,
 	}

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/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/loginguard.go

@@ -108,10 +108,10 @@ type failureWindow struct {
 //
 // A limiter that spends budget on arrival cannot protect a
 // single-admin product: behind the reverse proxy the deployment
-// requires, with TRUSTED_PROXIES unset, every client keys on the
-// proxy, so a stranger trickling five POSTs a minute keeps the one
-// bucket full and the operator's own correct password is answered 429
-// forever. There is no second administrative path.
+// requires, when TRUSTED_PROXIES does not cover it, every client
+// keys on the proxy, so a stranger trickling five POSTs a minute
+// keeps the one bucket full and the operator's own correct password
+// is answered 429 forever. There is no second administrative path.
 //
 // So budget is spent only by a FAILED verification. A correct
 // password is never throttled, whatever the counters say, which is

internal/middleware/ratelimit.go

@@ -123,9 +123,8 @@ func bucketKey(addr netip.Addr) string {
 	return prefix.String()
 }
 
-// isTrustedProxy reports whether addr belongs to a network the
-// operator listed in TRUSTED_PROXIES. The list is empty by default,
-// so by default nothing is trusted.
+// isTrustedProxy reports whether addr belongs to a network in
+// TRUSTED_PROXIES, which by default is the RFC 1918 private ranges.
 func (m *Middleware) isTrustedProxy(addr netip.Addr) bool {
 	for _, prefix := range m.params.Config.TrustedProxies {
 		if prefix.Contains(addr) {

internal/middleware/ratelimit_test.go

@@ -384,8 +384,8 @@ const (
 	// trustedProxyCIDR is the proxy network the forwarded-path
 	// tests configure, and trustedPeer an address inside it. A
 	// production deployment is required to run behind a reverse
-	// proxy with TRUSTED_PROXIES set, so this is the shape the
-	// bucketing has to hold in.
+	// proxy that TRUSTED_PROXIES covers, either by the default or by
+	// a set value, so this is the shape the bucketing has to hold in.
 	trustedProxyCIDR = "10.0.0.0/8"
 	trustedPeer      = "10.0.0.1:44444"
 )
@@ -426,8 +426,8 @@ func assertSharedBucket(
 }
 
 // TestRateLimitKey_SpoofedForwardedFromUntrustedPeer is the test
-// this gating exists for: with no trusted proxies configured (the
-// default), a client that rotates a forwarded header on every
+// this gating exists for: from a peer that is not a trusted
+// proxy, a client that rotates a forwarded header on every
 // request must stay in one bucket. If forwarded headers were
 // trusted unconditionally, each spoofed value would mint a fresh
 // bucket and the limit would stop no one.
@@ -1097,8 +1097,9 @@ func TestPostRateLimit_IPv4IndependentPerAddress(t *testing.T) {
 // that arrives from trustedPeer — a configured trusted proxy — and
 // names forwarded as its client in X-Forwarded-For. That is the
 // production path: a deployment is required to run behind a reverse
-// proxy with TRUSTED_PROXIES set, so the forwarded address, not the
-// peer, is what the limiters bucket on there.
+// proxy that TRUSTED_PROXIES covers, either by the default or by a
+// set value, so the forwarded address, not the peer, is what the
+// limiters bucket on there.
 func forwardedKeyFor(
 	t *testing.T, m *middleware.Middleware, forwarded string,
 ) string {
@@ -1178,9 +1179,9 @@ func TestRateLimitKey_ForwardedIPv6BucketsByPrefix(t *testing.T) {
 //
 // Every existing test of this fallback uses an IPv4 proxy, where
 // bucketKey is the identity function, so replacing the call with
-// peer.String() leaves the whole suite green. Only operator-listed
-// addresses reach this line and the fallback is fail-closed, so this
-// pins behaviour rather than fixing a defect.
+// peer.String() leaves the whole suite green. Only addresses inside
+// TRUSTED_PROXIES reach this line and the fallback is fail-closed, so
+// this pins behaviour rather than fixing a defect.
 func TestRateLimitKey_TrustedPeerUnusableForwardedMasksPeer(
 	t *testing.T,
 ) {

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
@@ -138,7 +139,9 @@ func (w *recoverResponseWriter) Unwrap() http.ResponseWriter {
 // 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 {
+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 +174,14 @@ 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 +196,27 @@ 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/server/error_page_test.go

@@ -0,0 +1,220 @@
+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="/sources" 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("/source/"+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(
+		"/source/"+wh.ID+"/targets/"+tgt.ID+"/edit", cookies,
+	)
+
+	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
+}
+
+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("/source/"+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("/source/"+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("/webhook/no-such-entrypoint", 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

@@ -16,8 +16,8 @@ import (
 // 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.
+// its first middleware after the recoverer, 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)
 	}
 }
 
@@ -147,18 +165,22 @@ 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
-		// the reverse proxy production requires, with TRUSTED_PROXIES
-		// unset, every client shares one bucket, so a limiter spent
-		// on arrival lets any stranger deny the operator the only
-		// administrative path. The handler verifies credentials first
-		// and charges only failures; see Handlers.authenticateUser.
+		// the reverse proxy production requires, when TRUSTED_PROXIES
+		// does not cover it, every client shares one bucket, so a
+		// limiter spent on arrival lets any stranger deny the operator
+		// the only administrative path. The handler verifies
+		// credentials first and charges only failures; see
+		// Handlers.authenticateUser.
 		r.Get("/login", s.h.HandleLoginPage())
 		r.Post("/login", s.h.HandleLoginSubmit())
 
@@ -168,10 +190,13 @@ 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())
@@ -183,10 +208,13 @@ func (s *Server) setupUserRoutes() {
 
 func (s *Server) setupSourceRoutes() {
 	s.router.Route("/sources", 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())
@@ -195,10 +223,13 @@ func (s *Server) setupSourceRoutes() {
 	})
 
 	s.router.Route("/source/{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/static_assets_test.go

@@ -13,9 +13,9 @@ import (
 
 // TestBaseTemplateScriptsAreServed walks every /s/ script the base
 // template loads on each page and fetches it through the real router.
-// Alpine.js is fetched at build time rather than committed, so nothing
-// in the repo guarantees it is present: this is the check that the page
-// still gets the JavaScript it asks for.
+// Alpine.js is extracted from its tarball in 3p/ at build time, so the
+// file is not in the tree: this is the check that the page still gets
+// the JavaScript it asks for.
 func TestBaseTemplateScriptsAreServed(t *testing.T) {
 	t.Parallel()
 

script/assets

@@ -0,0 +1,16 @@
+#!/bin/sh
+# script/assets: extract Alpine.js from its npm package tarball, committed
+# in 3p/, to static/js/alpine.min.js, where go:embed reads it. The
+# extracted file is not committed. script/test, make build and make dev run
+# this first.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    tar -xzOf 3p/alpinejs-3.14.9.tgz package/dist/cdn.min.js \
+        >static/js/alpine.min.js
+}
+
+main "$@"

script/bootstrap

@@ -4,9 +4,7 @@
 # installed tools are skipped. Base tooling comes from nix, apt, brew,
 # or apk (detected in that order); assumes NOTHING is present (not git,
 # make, or go). golangci-lint is deliberately not installed: linting runs
-# only in docker, via script/lint and Dockerfile.lint. Finishes by running
-# script/fetch-assets, which installs the hash-pinned third-party browser
-# assets the repo does not commit.
+# only in docker, via script/lint and Dockerfile.lint.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
@@ -69,11 +67,6 @@ main() {
 
     go mod download
 
-    # Third-party browser assets are not committed; fetch and verify them
-    # so a fresh clone can build and test.
-    if missing curl; then pkg_install curl curl curl curl; fi
-    "$ROOT/script/fetch-assets"
-
     echo "bootstrap complete"
 }
 

script/check

@@ -1,6 +1,7 @@
 #!/bin/sh
 # script/check: run all checks (test, lint, fmt-check). Our own
-# extension to scripts-to-rule-them-all. Must not modify any files.
+# extension to scripts-to-rule-them-all.
+# Writes only the ignored static/js/alpine.min.js, through script/test.
 # Generic: usually needs no adaptation.
 set -eu
 

script/fetch-assets

@@ -1,104 +0,0 @@
-#!/bin/sh
-# script/fetch-assets: download the third-party browser assets the web UI
-# ships and install them under static/. Minified bundles are not committed
-# (REPO_POLICIES.md: no build artifacts in version control), so the build
-# fetches them here. Every download is verified against a hardcoded sha256
-# before it is installed, and any mismatch aborts. Idempotent: an asset
-# already present with its pinned hash is left alone.
-set -eu
-
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
-
-# The sha256 of each installed asset lives in static/vendor.sha256, in
-# sha256sum(1) format, with paths relative to static/. That file is the
-# single source of truth: this script verifies against it, and
-# static/vendor_test.go asserts the bytes embedded into the binary match
-# it, so the hash cannot rot into a value nothing checks.
-MANIFEST="static/vendor.sha256"
-
-# Alpine.js 3.14.9, 2026-08-17. Fetched from registry.npmjs.org, the
-# publisher of record; the jsDelivr and unpkg copies are mirrors of this
-# same tarball. dist/cdn.min.js is the browser build Alpine publishes for
-# a <script> tag.
-ALPINE_VERSION="3.14.9"
-ALPINE_URL="https://registry.npmjs.org/alpinejs/-/alpinejs-${ALPINE_VERSION}.tgz"
-# sha256 of alpinejs-3.14.9.tgz
-ALPINE_TARBALL_SHA256="97dad7c0c81e659cfc8e7700055da9770f8186187cb9a8a76efb57e00d5ce52a"
-ALPINE_MEMBER="package/dist/cdn.min.js"
-ALPINE_DEST="js/alpine.min.js"
-
-sha256_of() {
-    if command -v sha256sum >/dev/null 2>&1; then
-        sha256sum "$1" | cut -d' ' -f1
-    else
-        shasum -a 256 "$1" | cut -d' ' -f1
-    fi
-}
-
-# expected_sha256 <path-relative-to-static>
-expected_sha256() {
-    awk -v want="$1" '$2 == want { print $1; found = 1 }
-        END { if (!found) exit 1 }' "$ROOT/$MANIFEST"
-}
-
-# verify <file> <expected-sha256> <what>
-verify() {
-    actual="$(sha256_of "$1")"
-    if [ "$actual" != "$2" ]; then
-        echo "fetch-assets: sha256 mismatch for $3" >&2
-        echo "  expected: $2" >&2
-        echo "  actual:   $actual" >&2
-        exit 1
-    fi
-}
-
-# up_to_date <path-relative-to-static> <expected-sha256>
-up_to_date() {
-    [ -f "$ROOT/static/$1" ] || return 1
-    [ "$(sha256_of "$ROOT/static/$1")" = "$2" ]
-}
-
-fetch_alpine() {
-    want="$(expected_sha256 "$ALPINE_DEST")"
-
-    if up_to_date "$ALPINE_DEST" "$want"; then
-        echo "fetch-assets: static/$ALPINE_DEST already at $want"
-        return 0
-    fi
-
-    echo "fetch-assets: fetching Alpine.js $ALPINE_VERSION from $ALPINE_URL"
-    tmp="$(mktemp -d)"
-    trap 'rm -rf "$tmp"' EXIT INT TERM
-    curl -fsSL -o "$tmp/alpine.tgz" "$ALPINE_URL"
-    verify "$tmp/alpine.tgz" "$ALPINE_TARBALL_SHA256" "alpinejs-${ALPINE_VERSION}.tgz"
-    tar -xzOf "$tmp/alpine.tgz" "$ALPINE_MEMBER" >"$tmp/alpine.min.js"
-    verify "$tmp/alpine.min.js" "$want" "$ALPINE_MEMBER from alpinejs-${ALPINE_VERSION}.tgz"
-
-    mkdir -p "$(dirname "$ROOT/static/$ALPINE_DEST")"
-    cp "$tmp/alpine.min.js" "$ROOT/static/$ALPINE_DEST"
-    rm -rf "$tmp"
-    trap - EXIT INT TERM
-    echo "fetch-assets: installed static/$ALPINE_DEST ($want)"
-}
-
-# Re-check every manifest entry against what is now on disk, so an entry
-# no script installs fails loudly instead of passing silently.
-verify_manifest() {
-    while read -r want path; do
-        case "$want" in '' | '#'*) continue ;; esac
-        if [ ! -f "$ROOT/static/$path" ]; then
-            echo "fetch-assets: $MANIFEST lists static/$path, which is missing" >&2
-            exit 1
-        fi
-        verify "$ROOT/static/$path" "$want" "static/$path"
-    done <"$ROOT/$MANIFEST"
-}
-
-main() {
-    cd "$ROOT"
-    fetch_alpine
-    verify_manifest
-    echo "fetch-assets: all assets in $MANIFEST verified"
-}
-
-main "$@"

script/test

@@ -28,6 +28,7 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
+    "$ROOT/script/assets"
     go test -v -race -timeout 90s ./...
 }
 

static/vendor.sha256

@@ -1 +0,0 @@
-3ed1eed252488921df65e363d6715deb04d7f92aaedb9e52199fdf73cb1e0ad3  js/alpine.min.js

static/vendor_test.go

@@ -1,92 +0,0 @@
-package static_test
-
-import (
-	"bufio"
-	"crypto/sha256"
-	"encoding/hex"
-	"os"
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-
-	"sneak.berlin/go/webhooker/static"
-)
-
-const manifestPath = "vendor.sha256"
-
-// fetchHint is appended to every failure here: the assets the manifest
-// covers are fetched by the build, not committed, so a fresh clone that
-// has not run script/fetch-assets fails this test and should be told why.
-const fetchHint = "run `script/fetch-assets` (or `make assets`) to install " +
-	"the pinned third-party assets"
-
-// TestVendoredAssetsMatchManifest asserts that every asset listed in
-// static/vendor.sha256 is embedded in the binary with exactly the pinned
-// bytes. script/fetch-assets verifies the same hashes at download time;
-// this test verifies them again on what actually ships, so a build that
-// skipped, cached, or subverted the fetch cannot produce a binary serving
-// unpinned third-party JavaScript.
-func TestVendoredAssetsMatchManifest(t *testing.T) {
-	t.Parallel()
-
-	entries := readManifest(t)
-	require.NotEmpty(t, entries, "%s lists no assets", manifestPath)
-
-	for path, want := range entries {
-		t.Run(path, func(t *testing.T) {
-			t.Parallel()
-
-			data, err := static.Static.ReadFile(path)
-			require.NoErrorf(
-				t, err,
-				"%s is listed in %s but is not embedded; %s",
-				path, manifestPath, fetchHint,
-			)
-
-			sum := sha256.Sum256(data)
-			got := hex.EncodeToString(sum[:])
-			require.Equalf(
-				t, want, got,
-				"embedded %s does not match its pinned sha256 in %s; %s",
-				path, manifestPath, fetchHint,
-			)
-		})
-	}
-}
-
-// readManifest parses static/vendor.sha256, which is in sha256sum(1)
-// format with paths relative to static/.
-func readManifest(t *testing.T) map[string]string {
-	t.Helper()
-
-	f, err := os.Open(manifestPath)
-	require.NoError(t, err, "opening %s", manifestPath)
-
-	defer func() { require.NoError(t, f.Close()) }()
-
-	entries := make(map[string]string)
-	scanner := bufio.NewScanner(f)
-
-	for scanner.Scan() {
-		line := strings.TrimSpace(scanner.Text())
-		if line == "" || strings.HasPrefix(line, "#") {
-			continue
-		}
-
-		fields := strings.Fields(line)
-		require.Lenf(
-			t, fields, 2,
-			"%s: malformed entry %q, want \"<sha256>  <path>\"",
-			manifestPath, line,
-		)
-
-		sum, path := fields[0], fields[1]
-		require.Lenf(t, sum, 64, "%s: %q is not a sha256", manifestPath, sum)
-		entries[path] = sum
-	}
-
-	require.NoError(t, scanner.Err(), "reading %s", manifestPath)
-
-	return entries
-}

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="/sources" class="btn-secondary">Back to webhooks</a>
+    {{else}}
+    <a href="/pages/login" class="btn-primary">Sign in</a>
+    {{end}}
+</div>
+{{end}}

templates/navbar.html

@@ -24,10 +24,14 @@
                 </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}}
             {{else}}
             <a href="/pages/login" class="btn-primary">Login</a>
             {{end}}
@@ -40,10 +44,12 @@
             {{if .User}}
             <a href="/sources" 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}}
             {{else}}
             <a href="/pages/login" class="btn-primary w-full">Login</a>
             {{end}}

templates/profile.html

@@ -41,10 +41,6 @@
                     <dt class="w-32 text-sm font-medium text-gray-500">Username</dt>
                     <dd class="text-sm text-gray-900">{{.User.Username}}</dd>
                 </div>
-                <div class="flex">
-                    <dt class="w-32 text-sm font-medium text-gray-500">Account Type</dt>
-                    <dd class="text-sm text-gray-900">Standard User</dd>
-                </div>
             </dl>
         </div>
     </div>

templates/source_detail.html

@@ -181,18 +181,30 @@
     <!-- Recent Events -->
     <div class="card mt-6">
         <div class="p-4 border-b border-gray-200 flex justify-between items-center">
-            <h2 class="text-lg font-medium text-gray-900">Recent Events</h2>
+            <h2 class="text-lg font-medium text-gray-900">50 Most Recent Events</h2>
             <a href="/source/{{.Webhook.ID}}/logs" class="btn-text text-sm">View All</a>
         </div>
         <div class="divide-y divide-gray-100">
             {{range .Events}}
             <div class="p-4">
-                <div class="flex items-center justify-between">
-                    <div class="flex items-center gap-3">
+                <div class="flex flex-wrap items-center justify-between gap-3">
+                    <div class="flex flex-wrap items-center gap-3">
                         <span class="badge-info">{{.Method}}</span>
-                        <span class="text-sm text-gray-500">{{.ContentType}}</span>
+                        <span class="text-sm text-gray-500 break-all">{{.ContentType}}</span>
+                        {{if .ResubmittedFromID}}
+                        <span class="text-xs text-gray-500" title="This event is a copy of {{.ResubmittedFromID}}">resubmitted copy</span>
+                        {{end}}
+                    </div>
+                    <div class="flex flex-wrap items-center gap-3 text-xs text-gray-400">
+                        <span title="Body size">{{.Size}}</span>
+                        {{if .ProcessingTime}}
+                        <span title="Processing time: how long the slowest delivery took, from being queued to its last attempt">{{.ProcessingTime}}</span>
+                        {{end}}
+                        {{if .Status}}
+                        <span class="font-medium {{.StatusClass}}" title="HTTP status from the HTTP target">{{.Status}}</span>
+                        {{end}}
+                        <span title="{{.ReceivedUTC}}">{{.Received}}</span>
                     </div>
-                    <span class="text-xs text-gray-400">{{.CreatedAt.Format "2006-01-02 15:04:05 UTC"}}</span>
                 </div>
             </div>
             {{else}}