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 and the CSRF middleware's
refusal use the same page. Status codes are unchanged. The receiver,
the healthcheck and /metrics keep their plain answers. If the error
page itself cannot render, the answer is the same status in plain
text.

Model: opus-5-5

README.md

@@ -142,7 +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. 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) |
+| `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) |
 | `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
@@ -157,21 +157,6 @@ 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
@@ -389,37 +374,41 @@ 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 cover
-the addresses of your reverse proxies.
+`X-Forwarded-For` header the rate limiters believe, so it should name
+the addresses of your reverse proxies and nothing else.
 
 `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. 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.
+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.
 
-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.
+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.
 
 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
@@ -435,10 +424,20 @@ 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.
 
-Your proxy must therefore **append** the peer address to
-`X-Forwarded-For` (nginx `$proxy_add_x_forwarded_for`, HAProxy
-`option forwardfor`, Caddy and AWS ALB by default), and must append a
-bare address with no port.
+Two operator requirements follow:
+
+- Your proxy must **append** the peer address to `X-Forwarded-For`
+  (nginx `$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.
 
 #### Sessions
 
@@ -737,15 +736,10 @@ 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`: 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).
+    - `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).
     - 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`.
@@ -808,16 +802,12 @@ 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. **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).
+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.
 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
@@ -1370,11 +1360,10 @@ 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` 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))
+  `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))
 - **[Prometheus](https://prometheus.io)** for metrics, served at
   `/metrics` behind basic auth
 - **[Sentry](https://sentry.io)** for optional error reporting
@@ -1653,7 +1642,6 @@ 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
@@ -2545,44 +2533,47 @@ 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, 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
+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
 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). 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
+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
 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 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.
+  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`.
 - 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.
+  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.
 
 #### 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 wherever clients share one bucket, as they do
-behind a reverse proxy that `TRUSTED_PROXIES` does not cover: a
+arrival is a lockout in this deployment shape: sharing one bucket, 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:
@@ -2679,10 +2670,8 @@ 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. `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)).
+real client address. Setting `TRUSTED_PROXIES` does not stop the
+saturation, but it makes the source visible in the failure logs.
 
 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
@@ -3040,9 +3029,10 @@ 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` covers the reverse proxy; otherwise every client
+  `TRUSTED_PROXIES` names the reverse proxy; unset, every client
   shares one bucket, which costs precision rather than availability
-  (see [Rate Limiting](#rate-limiting))
+  (see [Rate Limiting](#rate-limiting)). webhooker warns at startup
+  whenever `TRUSTED_PROXIES` is empty
 - Prometheus metrics behind basic auth
 - Static assets embedded in binary (no filesystem access needed at
   runtime)

go.mod

@@ -4,7 +4,6 @@ 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
@@ -30,6 +29,7 @@ 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

@@ -75,11 +75,6 @@ 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
@@ -177,14 +172,13 @@ 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. 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.
+	// 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.
 	TrustedProxies []netip.Prefix
 
 	// AllowedEgressCIDRs is the set of networks a delivery target
@@ -466,15 +460,14 @@ 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 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) {
+// 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) {
 	v := strings.TrimSpace(os.Getenv(key))
 	if v == "" {
-		v = defaultValue
+		return nil, nil
 	}
 
 	var prefixes []netip.Prefix
@@ -688,12 +681,12 @@ func loadFromEnv() (*Config, error) {
 		return nil, err
 	}
 
-	trustedProxies, err := envPrefixList("TRUSTED_PROXIES", defaultTrustedProxies)
+	trustedProxies, err := envPrefixList("TRUSTED_PROXIES")
 	if err != nil {
 		return nil, err
 	}
 
-	allowedEgressCIDRs, err := envPrefixList("ALLOWED_EGRESS_CIDRS", "")
+	allowedEgressCIDRs, err := envPrefixList("ALLOWED_EGRESS_CIDRS")
 	if err != nil {
 		return nil, err
 	}
@@ -767,6 +760,50 @@ 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.
@@ -812,6 +849,7 @@ 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

@@ -551,11 +551,6 @@ 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
@@ -564,21 +559,18 @@ 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: defaultProxies,
+			expected: []string{},
 		},
 		{
-			name:     "blank value uses default",
+			name:     "blank value trusts nothing",
 			set:      true,
 			value:    "  ",
-			expected: defaultProxies,
-		},
-		{
-			name:     "set value replaces the default entirely",
-			set:      true,
-			value:    "203.0.113.7",
-			expected: []string{"203.0.113.7/32"},
+			expected: []string{},
 		},
 		{
 			name:  caseValidValueParsed,
@@ -853,6 +845,101 @@ 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

@@ -6,6 +6,21 @@ 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

@@ -31,11 +31,6 @@ 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/delivery/ssrf.go

@@ -43,13 +43,6 @@ 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
 		}
@@ -103,10 +103,9 @@ 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, 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.
+// 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.
 //
 // Verifying first means every login POST costs an Argon2id hash, so
 // the work is taken under a bounded number of verification slots.
@@ -166,11 +165,7 @@ 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
 	}
@@ -242,24 +237,14 @@ 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
 	}
@@ -268,11 +253,7 @@ 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
-	// when TRUSTED_PROXIES does not cover it every client — attacker
+	// TRUSTED_PROXIES defaults to empty, so 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, 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.
+// 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.
 //
 // This fails if credentials stop being verified ahead of the limiter.
 func TestLogin_StrangersFloodCannotLockOutTheOperator(t *testing.T) {

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

@@ -204,7 +204,6 @@ 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 = 50
+	recentEventLimit = 20
 	// 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 +173,72 @@ 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,
+) {
+	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 +291,17 @@ 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 +315,16 @@ 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 +337,7 @@ func (s *Handlers) renderTemplate(
 // this reason.
 func (s *Handlers) executeTemplate(
 	w http.ResponseWriter,
+	r *http.Request,
 	tmpl *template.Template,
 	data any,
 ) {
@@ -280,10 +348,7 @@ 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/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

@@ -88,8 +88,6 @@ 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) {
@@ -128,7 +126,9 @@ func TestUserRoute_Unauthenticated_RedirectedByMiddleware(t *testing.T) {
 
 	var sess *session.Session
 
-	app := newTestApp(t, &log, &cfg, &sess)
+	var h *handlers.Handlers
+
+	app := newTestApp(t, &log, &cfg, &sess, &h)
 	app.RequireStart()
 
 	t.Cleanup(app.RequireStop)
@@ -139,7 +139,7 @@ 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

@@ -1,293 +0,0 @@
-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

@@ -1,362 +0,0 @@
-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

@@ -62,23 +62,6 @@ 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,
@@ -104,7 +87,9 @@ func serveSourceDetailPage(
 	w := httptest.NewRecorder()
 	h.HandleSourceDetail().ServeHTTP(w, req)
 
-	return w
+	require.Equal(t, http.StatusOK, w.Code)
+
+	return w.Body.String()
 }
 
 // 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
 		}
@@ -415,23 +407,16 @@ func (h *Handlers) renderSourceDetail(
 		"webhook_id = ?", webhook.ID,
 	).Find(&targets)
 
-	var events []RecentEventView
+	var events []database.Event
 
 	if h.dbMgr.DBExists(webhook.ID) {
-		webhookDB, err := h.dbMgr.GetDB(webhook.ID)
-		if err != nil {
-			h.serverError(w, "failed to get webhook database", err)
-
-			return
-		}
-
-		events, err = loadRecentEvents(
-			webhookDB, webhook.ID, singleHTTPTargetID(targets),
-		)
-		if err != nil {
-			h.serverError(w, "failed to load recent events", err)
-
-			return
+		webhookDB, dbErr := h.dbMgr.GetDB(webhook.ID)
+		if dbErr == nil {
+			webhookDB.Where(
+				"webhook_id = ?", webhook.ID,
+			).Order("created_at DESC").Limit(
+				recentEventLimit,
+			).Find(&events)
 		}
 	}
 
@@ -482,7 +467,7 @@ 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
 		}
@@ -517,7 +502,7 @@ 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
 		}
@@ -526,9 +511,7 @@ 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
 		}
@@ -582,7 +565,7 @@ 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
 	}
@@ -612,7 +595,7 @@ 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
 		}
@@ -639,7 +622,7 @@ 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
 	}
@@ -665,7 +648,7 @@ 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
@@ -809,7 +792,7 @@ 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
 	}
@@ -831,7 +814,7 @@ 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
 		}
@@ -839,7 +822,7 @@ 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
@@ -949,6 +932,7 @@ 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,
@@ -962,7 +946,7 @@ 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
@@ -999,7 +983,7 @@ 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
@@ -1008,7 +992,7 @@ 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
@@ -1231,7 +1215,7 @@ 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
 		}
@@ -1240,9 +1224,7 @@ 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
 		}
@@ -1258,7 +1240,7 @@ 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
 		}
@@ -1289,7 +1271,7 @@ 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
 		}
@@ -1298,9 +1280,7 @@ 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
 		}
@@ -1371,7 +1351,7 @@ 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
 	}
@@ -1465,7 +1445,7 @@ 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:
@@ -1515,7 +1495,7 @@ 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,
@@ -1537,7 +1517,7 @@ func (h *Handlers) buildSlackTargetConfig(
 		return "", err
 	}
 
-	return marshalTargetConfig(w, delivery.SlackTargetConfig{
+	return h.marshalTargetConfig(w, r, delivery.SlackTargetConfig{
 		WebhookURL: targetURL,
 	})
 }
@@ -1591,16 +1571,14 @@ 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
 	}
@@ -1616,6 +1594,7 @@ 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)
@@ -1634,8 +1613,8 @@ func (h *Handlers) buildDatabaseTargetConfig(
 		return "", err
 	}
 
-	return marshalTargetConfig(
-		w, map[string]any{"expiry": expiry},
+	return h.marshalTargetConfig(
+		w, r, map[string]any{"expiry": expiry},
 	)
 }
 
@@ -1689,7 +1668,7 @@ 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
 		}
@@ -1699,11 +1678,7 @@ 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
 		}
@@ -1793,18 +1768,14 @@ 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
@@ -230,7 +243,6 @@ 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, 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.
+// 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.
 //
 // 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

@@ -123,8 +123,9 @@ func bucketKey(addr netip.Addr) string {
 	return prefix.String()
 }
 
-// isTrustedProxy reports whether addr belongs to a network in
-// TRUSTED_PROXIES, which by default is the RFC 1918 private ranges.
+// 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.
 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 that TRUSTED_PROXIES covers, either by the default or by
-	// a set value, so this is the shape the bucketing has to hold in.
+	// proxy with TRUSTED_PROXIES set, 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: from a peer that is not a trusted
-// proxy, a client that rotates a forwarded header on every
+// this gating exists for: with no trusted proxies configured (the
+// default), 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.
@@ -1097,9 +1097,8 @@ 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 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.
+// proxy with TRUSTED_PROXIES set, 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 {
@@ -1179,9 +1178,9 @@ 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 addresses inside
-// TRUSTED_PROXIES 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 operator-listed
+// addresses 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/server/error_page_test.go

@@ -0,0 +1,155 @@
+package server_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strconv"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/config"
+)
+
+// 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.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_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/routes.go

@@ -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()
 }
@@ -150,16 +158,15 @@ func (s *Server) setupPageRoutes() {
 		// 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, 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.
+		// 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.
 		r.Get("/login", s.h.HandleLoginPage())
 		r.Post("/login", s.h.HandleLoginSubmit())
 
@@ -172,7 +179,7 @@ func (s *Server) setupUserRoutes() {
 		// 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())
@@ -187,7 +194,7 @@ func (s *Server) setupSourceRoutes() {
 		// 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())
@@ -199,7 +206,7 @@ func (s *Server) setupSourceRoutes() {
 		// 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())

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>
+            {{/* The page for an unknown path is served outside the routes
+                 that issue a form token, 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

@@ -41,6 +41,10 @@
                     <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

@@ -181,30 +181,18 @@
     <!-- 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">50 Most Recent Events</h2>
+            <h2 class="text-lg font-medium text-gray-900">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 flex-wrap items-center justify-between gap-3">
-                    <div class="flex flex-wrap items-center gap-3">
+                <div class="flex items-center justify-between">
+                    <div class="flex items-center gap-3">
                         <span class="badge-info">{{.Method}}</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>
+                        <span class="text-sm text-gray-500">{{.ContentType}}</span>
                     </div>
+                    <span class="text-xs text-gray-400">{{.CreatedAt.Format "2006-01-02 15:04:05 UTC"}}</span>
                 </div>
             </div>
             {{else}}