Bound shutdown hooks by their stop context (closes #102)

fx hands OnStop a context carrying the application's stop timeout,
and the delivery engine, the retention reaper, and the archive
sweeper all discarded it and called wg.Wait() bare. A worker wedged
inside a delivery target that never returns, or a sweep blocked on a
locked SQLite database, hung the process forever instead of letting
it exit when the timeout expired.

All three now wait through internal/lifecycle.WaitForShutdown, which
selects the drained WaitGroup against the stop context and, on
timeout, logs at error naming the component and returns an error
rather than reporting a clean stop.

Engine.stop also gains the cancel != nil guard its two mirrored
components already had.

README.md

@@ -94,7 +94,7 @@ TTY detection, and security headers are always applied.
 | `METRICS_PASSWORD`      | Basic auth password for `/metrics`  | `""`     |
 | `SENTRY_DSN`            | Sentry error reporting DSN          | `""`     |
 | `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` |
+| `RECEIVER_RATE_LIMIT`   | Receiver requests/minute per IP per entrypoint | `120` |
 | `TRUSTED_PROXIES`       | CIDRs whose forwarded headers are trusted | `""` (none) |
 
 #### Trusted proxies
@@ -851,20 +851,6 @@ legitimate webhook senders). Requests over the limit receive HTTP 429
 with a `Retry-After` header. A set-but-invalid `RECEIVER_RATE_LIMIT`
 value aborts startup rather than silently falling back to the default.
 
-A second limit sits in front of that one, keyed on the client IP alone
-and covering the whole route at ten times `RECEIVER_RATE_LIMIT` requests
-per minute (default 1200). The per-entrypoint limit needs it: the route
-pattern matches any single path segment, so a client that invents a
-fresh path per request gets a fresh per-entrypoint bucket every time and
-would otherwise have no aggregate limit at all — while each of those
-requests still costs an entrypoint lookup before it 404s. The aggregate
-limit leaves room for one address to drive several entrypoints at their
-full rate, and it is not configurable separately.
-
-Requests to a `/webhook/` path that names no entrypoint are logged at
-`DEBUG` only, since the path is attacker-controlled; the request itself
-still appears in the access log.
-
 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

TODO.md

@@ -1,62 +1,31 @@
 # Workflow
 
-One issue per unit of work, one branch and one PR per issue:
+* branch (from `main`)
-
+* do the work in Next Step
-* ensure a tracked issue exists with a definition of done
+* move Next Step to the top of Completed Steps
-* branch from `next` (never from `main`)
+* move the top item of Future Steps into Next Step
-* do the work; open a PR based on `next` (never on `main`)
+* commit (`TODO.md` changes in the same commit as the work)
-* pass an independent review, then the manager squash-merges into `next`
+* merge to `main` if the branch is not protected, otherwise open a PR
-* push; nothing stays local-only
+* push
-
-`next` is the branch for the next milestone and must stay green and
-mergeable to `main` without notice. One `next` -> `main` PR accumulates
-the milestone; releases are cut from `main` separately.
-
-Issue branches do NOT touch this file — the manager maintains it on
-`next`. Every branch editing `TODO.md` conflicts with every other
-(#112).
 
 # Status
 
-pre-1.0. No git tags exist. `main` (4f5ecb1) is a working webhook proxy
+pre-1.0. No git tags exist. main (4f5ecb1) is a working webhook proxy
 with auth, CSRF/SSRF protections, login rate limiting, Slack target,
 event retention (#63), the database archiving target (#43), the admin
 password change flow (#65), policy compliance (#6), pinned lint tooling
-(#55), and fail-loud configuration parsing (#80).
+(#55), and fail-loud configuration parsing (#80). Note: TODO.md was
-
+deliberately deleted from this repo in f9a9569 (2026-03-01, #6); its
-`next` (9bfd033) holds the completed 1.0.0 milestone: every issue in it
+content was folded into the README TODO section, which this draft
-is closed, and it is verified green by cache-defeated container runs
+reconstructs as of 2026-07-06.
-rather than by the CI badge, which can pass without executing anything
-(#119). Note: TODO.md was deliberately deleted from this repo in f9a9569
-(2026-03-01, #6); its content was folded into the README TODO section,
-which this draft reconstructs as of 2026-07-06.
 
 # Next Step
 
-Tag 1.0.0 from `main` once the milestone PR merges, then repair the CI
+Manual event redelivery from the web UI (replay is a core promised
-gate (#119) before the next cycle's work lands — a gate that can report
+capability in the README rationale).
-success without running is the one thing every other guarantee here
-rests on.
 
 # Completed Steps
 
-- 2026-08-12 Bound the `X-Forwarded-For` scan's allocation to the hop
-  cap: the reverse walk cuts entries with `strings.LastIndexByte`
-  instead of joining and splitting, so a 1 MB header allocates 16 bytes
-  rather than 1.6 MB per request on the unauthenticated receiver.
-  Semantics proven unchanged by differential testing against the
-  previous implementation (#133)
-- 2026-08-12 Cap the `X-Forwarded-For` hop walk at 64 entries, so an
-  attacker-supplied chain cannot burn unbounded CPU in the rate-limit
-  key function; running off the end falls back to the peer address
-  (#124)
-- 2026-08-12 Gate forwarded-header trust behind a `TRUSTED_PROXIES` CIDR
-  list: all three rate limiters key on the connection's own address
-  unless the direct peer is a configured proxy, in which case
-  `X-Forwarded-For` is walked right to left for the first non-proxy hop.
-  Default trusts nothing, and a set-but-unparseable value aborts
-  startup. Before this, any client could mint a fresh bucket or drain
-  another's by rotating a spoofed header (#88)
 - 2026-08-11 Web UI cleanup: nav terminology unified on Webhooks, the
   Profile settings placeholder removed, a progressive-enhancement copy
   button for the entrypoint URL, and retention form copy that states the

internal/database/export_test.go

@@ -46,8 +46,19 @@ func (r *RetentionReaper) ExportStart() {
 }
 
 // ExportStop stops the reaper's background loop for tests.
-func (r *RetentionReaper) ExportStop() {
+func (r *RetentionReaper) ExportStop(ctx context.Context) error {
-	r.stop()
+	return r.stop(ctx)
+}
+
+// ExportWedgeLoop adds a goroutine to the reaper's WaitGroup that
+// never observes cancellation and returns only when release is
+// closed. It stands in for a sweep stuck on a locked database.
+func (r *RetentionReaper) ExportWedgeLoop(
+	release <-chan struct{},
+) {
+	r.wg.Go(func() {
+		<-release
+	})
 }
 
 // ExportSetInterval overrides the sweep interval for tests.

internal/database/retention.go

@@ -10,6 +10,7 @@ import (
 	"go.uber.org/fx"
 	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/config"
+	"sneak.berlin/go/webhooker/internal/lifecycle"
 	"sneak.berlin/go/webhooker/internal/logger"
 )
 
@@ -62,8 +63,9 @@ func NewRetentionReaper(
 }
 
 // registerHooks wires the reaper's start and stop into the fx
-// lifecycle. The start hook's context is deliberately ignored: see
+// lifecycle. The start hook's context is deliberately ignored (see
-// start for why the sweep loop must not inherit it.
+// start for why the sweep loop must not inherit it); the stop hook's
+// context is honoured (see stop).
 func (r *RetentionReaper) registerHooks(lc fx.Lifecycle) {
 	lc.Append(fx.Hook{
 		//nolint:contextcheck // Not inheriting the hook context is
@@ -73,10 +75,8 @@ func (r *RetentionReaper) registerHooks(lc fx.Lifecycle) {
 
 			return nil
 		},
-		OnStop: func(_ context.Context) error {
+		OnStop: func(ctx context.Context) error {
-			r.stop()
+			return r.stop(ctx)
-
-			return nil
 		},
 	})
 }
@@ -105,15 +105,27 @@ func (r *RetentionReaper) start() {
 	)
 }
 
-func (r *RetentionReaper) stop() {
+// stop cancels the sweep loop's context and waits for it to
+// exit, bounded by the stop hook's context: a sweep wedged on a
+// locked database must not hang the process past fx's stop
+// timeout.
+func (r *RetentionReaper) stop(ctx context.Context) error {
 	r.log.Info("retention reaper stopping")
 
 	if r.cancel != nil {
 		r.cancel()
 	}
 
-	r.wg.Wait()
+	err := lifecycle.WaitForShutdown(
+		ctx, r.log, "retention reaper", &r.wg,
+	)
+	if err != nil {
+		return err
+	}
+
 	r.log.Info("retention reaper stopped")
+
+	return nil
 }
 
 func (r *RetentionReaper) run(ctx context.Context) {

internal/database/retention_lifecycle_test.go

@@ -26,6 +26,13 @@ const (
 	// reaperTestRetentionDays is the retention policy the lifecycle
 	// tests give their webhook.
 	reaperTestRetentionDays = 30
+
+	// reaperWedgeStopTimeout is the stop timeout the wedged-shutdown
+	// test hands OnStop, standing in for fx's StopTimeout. The test
+	// asserts only that the hook returns at all, and allows it
+	// reaperStopTimeout — forty times this budget — to do so, so no
+	// assertion races the wall clock.
+	reaperWedgeStopTimeout = 250 * time.Millisecond
 )
 
 // recordingLifecycle is a minimal fx.Lifecycle that records the
@@ -207,3 +214,59 @@ func TestRetentionReaper_StopHookStopsLoop(t *testing.T) {
 		"a stopped reaper must not sweep anything",
 	)
 }
+
+// TestRetentionReaper_StopHookHonoursStopTimeout is the
+// regression test for a shutdown that could never complete. fx
+// hands OnStop a context carrying the application's stop timeout;
+// an OnStop that discards it and calls wg.Wait() bare hangs the
+// process forever on a sweep blocked on a locked SQLite database
+// — precisely when a bounded shutdown matters most.
+//
+// The wedged goroutine here never observes cancellation, so the
+// hook can only return by honouring its context, and it must say
+// so rather than reporting a clean stop.
+func TestRetentionReaper_StopHookHonoursStopTimeout(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupRetentionTest(t)
+
+	env.reaper.ExportSetInterval(reaperTestInterval)
+
+	lc := startReaperViaHook(t, env.reaper)
+
+	release := make(chan struct{})
+
+	t.Cleanup(func() { close(release) })
+
+	env.reaper.ExportWedgeLoop(release)
+
+	stopCtx, cancel := context.WithTimeout(
+		context.Background(), reaperWedgeStopTimeout,
+	)
+	defer cancel()
+
+	var stopErr error
+
+	stopped := make(chan struct{})
+
+	go func() {
+		defer close(stopped)
+
+		stopErr = lc.hooks[0].OnStop(stopCtx)
+	}()
+
+	select {
+	case <-stopped:
+	case <-time.After(reaperStopTimeout):
+		t.Fatal(
+			"OnStop did not return: it discarded the stop " +
+				"context and is waiting on a wedged goroutine " +
+				"that will never observe cancellation",
+		)
+	}
+
+	require.ErrorIs(t, stopErr, context.DeadlineExceeded)
+	require.ErrorContains(t, stopErr, "retention reaper")
+}

internal/delivery/archive_sweeper.go

@@ -10,6 +10,7 @@ import (
 	"go.uber.org/fx"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/lifecycle"
 	"sneak.berlin/go/webhooker/internal/logger"
 )
 
@@ -67,10 +68,9 @@ func NewArchiveSweeper(
 }
 
 // registerHooks wires the sweeper's start and stop into the fx
-// lifecycle. Both hook contexts are deliberately ignored: see
+// lifecycle. The start hook's context is deliberately ignored
-// start for why the background loop must not inherit the start
+// (see start for why the background loop must not inherit it);
-// hook's context, and stop for why shutdown blocks on the loop
+// the stop hook's context is honoured (see stop).
-// rather than on the stop hook's deadline.
 func (s *ArchiveSweeper) registerHooks(lc fx.Lifecycle) {
 	lc.Append(fx.Hook{
 		//nolint:contextcheck // Not passing the hook context is
@@ -80,10 +80,8 @@ func (s *ArchiveSweeper) registerHooks(lc fx.Lifecycle) {
 
 			return nil
 		},
-		OnStop: func(_ context.Context) error {
+		OnStop: func(ctx context.Context) error {
-			s.stop()
+			return s.stop(ctx)
-
-			return nil
 		},
 	})
 }
@@ -113,15 +111,27 @@ func (s *ArchiveSweeper) start() {
 	)
 }
 
-func (s *ArchiveSweeper) stop() {
+// stop cancels the sweep loop's context and waits for it to
+// exit, bounded by the stop hook's context: a prune wedged on a
+// locked archive must not hang the process past fx's stop
+// timeout.
+func (s *ArchiveSweeper) stop(ctx context.Context) error {
 	s.log.Info("archive sweeper stopping")
 
 	if s.cancel != nil {
 		s.cancel()
 	}
 
-	s.wg.Wait()
+	err := lifecycle.WaitForShutdown(
+		ctx, s.log, "archive sweeper", &s.wg,
+	)
+	if err != nil {
+		return err
+	}
+
 	s.log.Info("archive sweeper stopped")
+
+	return nil
 }
 
 func (s *ArchiveSweeper) run(ctx context.Context) {

internal/delivery/archive_sweeper_test.go

@@ -14,7 +14,6 @@ import (
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"go.uber.org/fx"
 	"gorm.io/driver/sqlite"
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
@@ -226,17 +225,6 @@ func countArchivedRows(path string) (int64, error) {
 	return count, nil
 }
 
-// captureLifecycle is a minimal fx.Lifecycle that records the
-// hooks a component registers, so a test can invoke the real
-// OnStart/OnStop functions with a context of its choosing.
-type captureLifecycle struct {
-	hooks []fx.Hook
-}
-
-func (l *captureLifecycle) Append(h fx.Hook) {
-	l.hooks = append(l.hooks, h)
-}
-
 // TestArchiveSweeper_LoopOutlivesStartHookContext is the
 // regression test for a sweeper that never swept. fx calls
 // OnStart with a context carrying the application's start
@@ -270,7 +258,7 @@ func TestArchiveSweeper_LoopOutlivesStartHookContext(
 
 	// Drive the genuine fx hooks the application registers,
 	// rather than a test-only entry point.
-	lc := &captureLifecycle{}
+	lc := &recordingLifecycle{}
 	env.sweeper.ExportRegisterHooks(lc)
 	require.Len(t, lc.hooks, 1)
 
@@ -924,7 +912,36 @@ func TestArchiveSweeper_StopsCleanly(t *testing.T) {
 	env.sweeper.ExportSetInterval(time.Millisecond)
 	env.sweeper.ExportStart()
 
-	// stop blocks on the loop's WaitGroup, so returning at all
+	// stop blocks on the loop's WaitGroup, so returning without
-	// proves the loop observed the cancellation and exited.
+	// error proves the loop observed the cancellation and exited
-	env.sweeper.ExportStop()
+	// well inside the stop context.
+	require.NoError(
+		t, env.sweeper.ExportStop(context.Background()),
+	)
+}
+
+// TestArchiveSweeper_StopHookHonoursStopTimeout is the sweeper's
+// half of the same shutdown defect the engine and the retention
+// reaper carried: an OnStop that discards its context and waits
+// on the WaitGroup bare hangs the process forever on a prune
+// wedged inside a locked archive.
+func TestArchiveSweeper_StopHookHonoursStopTimeout(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	lc := &recordingLifecycle{}
+	env.sweeper.ExportRegisterHooks(lc)
+	require.Len(t, lc.hooks, 1)
+	require.NoError(t, lc.hooks[0].OnStart(context.Background()))
+
+	release := make(chan struct{})
+
+	t.Cleanup(func() { close(release) })
+
+	env.sweeper.ExportWedgeLoop(release)
+
+	requireStopHookExpires(t, lc.hooks[0], "archive sweeper")
 }

internal/delivery/engine.go

@@ -13,6 +13,7 @@ import (
 	"go.uber.org/fx"
 	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/lifecycle"
 	"sneak.berlin/go/webhooker/internal/logger"
 )
 
@@ -234,8 +235,9 @@ func (e *Engine) ScheduleRetry(
 }
 
 // registerHooks wires the engine's start and stop into the fx
-// lifecycle. The start hook's context is deliberately ignored:
+// lifecycle. The start hook's context is deliberately ignored
-// see start for why the worker pool must not inherit it.
+// (see start for why the worker pool must not inherit it); the
+// stop hook's context is honoured (see stop).
 func (e *Engine) registerHooks(lc fx.Lifecycle) {
 	lc.Append(fx.Hook{
 		//nolint:contextcheck // Not inheriting the hook context
@@ -245,10 +247,8 @@ func (e *Engine) registerHooks(lc fx.Lifecycle) {
 
 			return nil
 		},
-		OnStop: func(_ context.Context) error {
+		OnStop: func(ctx context.Context) error {
-			e.stop()
+			return e.stop(ctx)
-
-			return nil
 		},
 	})
 }
@@ -289,11 +289,26 @@ func (e *Engine) start() {
 	)
 }
 
-func (e *Engine) stop() {
+// stop cancels the worker pool's context and waits for the pool
+// to drain, bounded by the stop hook's context: a wedged worker
+// must not hang the process past fx's stop timeout.
+func (e *Engine) stop(ctx context.Context) error {
 	e.log.Info("delivery engine stopping")
+
+	if e.cancel != nil {
 		e.cancel()
-	e.wg.Wait()
+	}
+
+	err := lifecycle.WaitForShutdown(
+		ctx, e.log, "delivery engine", &e.wg,
+	)
+	if err != nil {
+		return err
+	}
+
 	e.log.Info("delivery engine stopped")
+
+	return nil
 }
 
 func (e *Engine) worker(ctx context.Context) {

internal/delivery/engine_integration_test.go

@@ -501,7 +501,7 @@ func TestWorkerLifecycle_StartStop(t *testing.T) {
 
 	iWaitForDelivered(t, s.WebhookDB, d.ID)
 
-	s.Engine.ExportStop()
+	require.NoError(t, s.Engine.ExportStop(context.Background()))
 }
 
 // iWaitForDelivered polls until the delivery reaches the
@@ -567,7 +567,7 @@ func TestWorkerLifecycle_ProcessesRetryChannel(
 
 	iWaitForDelivered(t, s.WebhookDB, d.ID)
 
-	s.Engine.ExportStop()
+	require.NoError(t, s.Engine.ExportStop(context.Background()))
 }
 
 // --- processDelivery: unknown target type ---

internal/delivery/engine_lifecycle_test.go

@@ -27,6 +27,13 @@ const (
 	// and a ready deliveryCh are chosen between at random and a
 	// doomed pool still delivers.
 	hookSettleDelay = 250 * time.Millisecond
+
+	// wedgeStopTimeout is the stop timeout a wedged-shutdown test
+	// hands OnStop, standing in for fx's StopTimeout. The test
+	// asserts only that the hook returns at all, and allows it
+	// hookStopTimeout — forty times this budget — to do so, so no
+	// assertion here races the wall clock.
+	wedgeStopTimeout = 250 * time.Millisecond
 )
 
 // recordingLifecycle is a minimal fx.Lifecycle that records the
@@ -40,6 +47,44 @@ func (l *recordingLifecycle) Append(h fx.Hook) {
 	l.hooks = append(l.hooks, h)
 }
 
+// requireStopHookExpires drives hook.OnStop with a stop context
+// that expires while a wedged goroutine is still running, and
+// requires the hook to return the deadline error naming
+// component instead of blocking on the WaitGroup forever.
+func requireStopHookExpires(
+	t *testing.T, hook fx.Hook, component string,
+) {
+	t.Helper()
+
+	stopCtx, cancel := context.WithTimeout(
+		context.Background(), wedgeStopTimeout,
+	)
+	defer cancel()
+
+	var stopErr error
+
+	stopped := make(chan struct{})
+
+	go func() {
+		defer close(stopped)
+
+		stopErr = hook.OnStop(stopCtx)
+	}()
+
+	select {
+	case <-stopped:
+	case <-time.After(hookStopTimeout):
+		t.Fatal(
+			"OnStop did not return: it discarded the stop " +
+				"context and is waiting on a wedged goroutine " +
+				"that will never observe cancellation",
+		)
+	}
+
+	require.ErrorIs(t, stopErr, context.DeadlineExceeded)
+	require.ErrorContains(t, stopErr, component)
+}
+
 // startEngineViaHook drives the genuine fx hooks the application
 // registers for the engine, handing OnStart a context that is
 // already done, and returns only once a pool that inherited that
@@ -197,3 +242,30 @@ func TestEngine_StopHookStopsWorkers(t *testing.T) {
 		"a stopped engine must not deliver anything",
 	)
 }
+
+// TestEngine_StopHookHonoursStopTimeout is the regression test
+// for a shutdown that could never complete. fx hands OnStop a
+// context carrying the application's stop timeout; an OnStop
+// that discards it and calls wg.Wait() bare hangs the process
+// forever on a single worker stuck inside a delivery target that
+// never returns — precisely when a bounded shutdown matters
+// most.
+//
+// The wedged goroutine here never observes cancellation, so the
+// hook can only return by honouring its context, and it must say
+// so rather than reporting a clean stop.
+func TestEngine_StopHookHonoursStopTimeout(t *testing.T) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	lc := startEngineViaHook(t, s.Engine)
+
+	release := make(chan struct{})
+
+	t.Cleanup(func() { close(release) })
+
+	s.Engine.ExportWedgeWorker(release)
+
+	requireStopHookExpires(t, lc.hooks[0], "delivery engine")
+}

internal/delivery/export_test.go

@@ -216,8 +216,19 @@ func (e *Engine) ExportRegisterHooks(lc fx.Lifecycle) {
 }
 
 // ExportStop exposes stop for testing.
-func (e *Engine) ExportStop() {
+func (e *Engine) ExportStop(ctx context.Context) error {
-	e.stop()
+	return e.stop(ctx)
+}
+
+// ExportWedgeWorker adds a goroutine to the engine's WaitGroup
+// that never observes cancellation and returns only when release
+// is closed. It stands in for a worker stuck inside a delivery
+// target that never returns, which is the only way stop can be
+// made to outlast its context.
+func (e *Engine) ExportWedgeWorker(release <-chan struct{}) {
+	e.wg.Go(func() {
+		<-release
+	})
 }
 
 // ExportDeliveryCh returns the delivery channel.
@@ -518,8 +529,19 @@ func (s *ArchiveSweeper) ExportRegisterHooks(lc fx.Lifecycle) {
 }
 
 // ExportStop stops the sweeper's background loop for tests.
-func (s *ArchiveSweeper) ExportStop() {
+func (s *ArchiveSweeper) ExportStop(ctx context.Context) error {
-	s.stop()
+	return s.stop(ctx)
+}
+
+// ExportWedgeLoop adds a goroutine to the sweeper's WaitGroup
+// that never observes cancellation and returns only when release
+// is closed. It stands in for a prune stuck on a locked archive.
+func (s *ArchiveSweeper) ExportWedgeLoop(
+	release <-chan struct{},
+) {
+	s.wg.Go(func() {
+		<-release
+	})
 }
 
 // ExportSetInterval overrides the sweep interval for tests.

internal/handlers/webhook.go

@@ -39,6 +39,12 @@ func (h *Handlers) HandleWebhook() http.HandlerFunc {
 			return
 		}
 
+		h.log.Info("webhook request received",
+			"entrypoint_uuid", entrypointUUID,
+			"method", r.Method,
+			"remote_addr", r.RemoteAddr,
+		)
+
 		entrypoint, ok := h.lookupEntrypoint(
 			w, r, entrypointUUID,
 		)
@@ -46,18 +52,6 @@ func (h *Handlers) HandleWebhook() http.HandlerFunc {
 			return
 		}
 
-		// Logged only once the UUID is known to name a real
-		// entrypoint. The UUID comes straight out of the path on
-		// the one unauthenticated endpoint, so logging it before
-		// the lookup let a client write an INFO line per invented
-		// path; the request itself is already in the access log
-		// and a miss is already logged at DEBUG.
-		h.log.Info("webhook request received",
-			"entrypoint_uuid", entrypointUUID,
-			"method", r.Method,
-			"remote_addr", r.RemoteAddr,
-		)
-
 		if !entrypoint.Active {
 			http.Error(w, "Gone", http.StatusGone)
 

internal/lifecycle/lifecycle.go

@@ -0,0 +1,57 @@
+// Package lifecycle holds helpers shared by the components that
+// register fx start and stop hooks.
+package lifecycle
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"sync"
+)
+
+// WaitForShutdown waits for wg to drain, bounded by ctx.
+//
+// fx hands OnStop a context carrying the application's stop
+// timeout. A bare wg.Wait() discards that deadline, so a single
+// goroutine that never observes cancellation — a delivery target
+// that never returns, a SQLite operation blocked on a lock —
+// hangs the process forever instead of letting it exit when the
+// timeout expires, which is exactly when a clean shutdown matters
+// most.
+//
+// On timeout it logs at error naming component and returns an
+// error: the goroutines are still running, and reporting success
+// would hide an unclean shutdown from the operator. The waiting
+// goroutine outlives this call and exits when (if) wg drains; it
+// holds nothing but the channel it closes.
+func WaitForShutdown(
+	ctx context.Context,
+	log *slog.Logger,
+	component string,
+	wg *sync.WaitGroup,
+) error {
+	done := make(chan struct{})
+
+	go func() {
+		defer close(done)
+
+		wg.Wait()
+	}()
+
+	select {
+	case <-done:
+		return nil
+	case <-ctx.Done():
+		log.Error(
+			"shutdown timed out, goroutines still running",
+			"component", component,
+			"error", ctx.Err(),
+		)
+
+		return fmt.Errorf(
+			"%s: shutdown timed out, "+
+				"goroutines still running: %w",
+			component, ctx.Err(),
+		)
+	}
+}

internal/lifecycle/lifecycle_test.go

@@ -0,0 +1,62 @@
+package lifecycle_test
+
+import (
+	"context"
+	"log/slog"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/lifecycle"
+)
+
+// waitTimeout is the stop budget the timeout case gives a
+// goroutine that never returns. The test's own patience is the
+// go test deadline, so the only thing this value affects is how
+// long the case takes.
+const waitTimeout = 100 * time.Millisecond
+
+func discardLogger() *slog.Logger {
+	return slog.New(slog.DiscardHandler)
+}
+
+func TestWaitForShutdown_DrainedGroup(t *testing.T) {
+	t.Parallel()
+
+	var wg sync.WaitGroup
+
+	wg.Go(func() {})
+
+	require.NoError(
+		t,
+		lifecycle.WaitForShutdown(
+			context.Background(), discardLogger(),
+			"test component", &wg,
+		),
+	)
+}
+
+func TestWaitForShutdown_ContextExpires(t *testing.T) {
+	t.Parallel()
+
+	release := make(chan struct{})
+
+	t.Cleanup(func() { close(release) })
+
+	var wg sync.WaitGroup
+
+	wg.Go(func() { <-release })
+
+	ctx, cancel := context.WithTimeout(
+		context.Background(), waitTimeout,
+	)
+	defer cancel()
+
+	err := lifecycle.WaitForShutdown(
+		ctx, discardLogger(), "test component", &wg,
+	)
+
+	require.ErrorIs(t, err, context.DeadlineExceeded)
+	require.ErrorContains(t, err, "test component")
+}

internal/middleware/export_test.go

@@ -25,11 +25,6 @@ func IPFromHostPort(hp string) string {
 	return ipFromHostPort(hp)
 }
 
-// ClientKeyForTest exposes clientKey for testing.
-func ClientKeyForTest(m *Middleware, r *http.Request) string {
-	return m.clientKey(r)
-}
-
 // IsClientTLS exposes isClientTLS for testing.
 func IsClientTLS(r *http.Request) bool {
 	return isClientTLS(r)
@@ -41,13 +36,3 @@ const LoginRateLimitConst = loginRateLimit
 // PasswordChangeRateLimitConst exposes the
 // passwordChangeRateLimit constant.
 const PasswordChangeRateLimitConst = passwordChangeRateLimit
-
-// ReceiverAggregateMultiplierConst exposes the
-// receiverAggregateMultiplier constant.
-const ReceiverAggregateMultiplierConst = receiverAggregateMultiplier
-
-// ReceiverAggregateLimitForTest exposes receiverAggregateLimit for
-// testing.
-func ReceiverAggregateLimitForTest(perEntrypoint int) int {
-	return receiverAggregateLimit(perEntrypoint)
-}

internal/middleware/ratelimit.go

@@ -1,7 +1,6 @@
 package middleware
 
 import (
-	"math"
 	"net/http"
 	"net/netip"
 	"slices"
@@ -33,21 +32,6 @@ const (
 	// receiver rate limit. The configured limit is expressed in
 	// requests per minute.
 	receiverRateInterval = 1 * time.Minute
-
-	// receiverAggregateMultiplier scales the configured
-	// per-entrypoint receiver limit into the aggregate limit one
-	// client IP may spend across the whole /webhook/* route. Ten
-	// entrypoints' worth lets a single sender address drive several
-	// entrypoints at their full rate, while still capping what one
-	// address costs the unauthenticated receiver.
-	receiverAggregateMultiplier = 10
-
-	// maxForwardedHops bounds how many X-Forwarded-For entries the
-	// chain walk examines. Real chains are one to three hops, but a
-	// client can pad the header up to MaxHeaderBytes, so without a
-	// bound every request pays a walk proportional to whatever the
-	// client sent.
-	maxForwardedHops = 64
 )
 
 // normalizeAddr strips the IPv4-in-IPv6 wrapper and any zone from
@@ -86,36 +70,14 @@ func (m *Middleware) isTrustedProxy(addr netip.Addr) bool {
 // a trusted proxy is the client. A hop that cannot be read as a bare
 // address ends the walk: past it the chain is not the shape assumed
 // here, so the caller falls back to the peer address.
-//
-// Only the last maxForwardedHops entries are examined. A longer chain
-// is padding, and running out of hops falls back to the peer address
-// the same way an unreadable hop does.
-//
-// The entries are cut off the right end of each header value in place
-// rather than split out of it: the receiver is unauthenticated and a
-// client can pad the header up to MaxHeaderBytes, so splitting would
-// allocate in proportion to the padding (about 8 MB for a 1 MB
-// header) before the cap could discard any of it. Multiple header
-// values are walked in reverse for the same reason, since joining
-// them copies the whole chain.
 func (m *Middleware) forwardedClientAddr(
 	r *http.Request,
 ) (netip.Addr, bool) {
-	seen := 0
+	hops := strings.Split(
-
+		strings.Join(r.Header.Values("X-Forwarded-For"), ","), ",",
-	for _, value := range slices.Backward(
+	)
-		r.Header.Values("X-Forwarded-For"),
-	) {
-		for last := false; !last && seen < maxForwardedHops; seen++ {
-			hop := value
-
-			comma := strings.LastIndexByte(value, ',')
-			if comma < 0 {
-				last = true
-			} else {
-				hop, value = value[comma+1:], value[:comma]
-			}
 
+	for _, hop := range slices.Backward(hops) {
 		hop = strings.TrimSpace(hop)
 		if hop == "" {
 			continue
@@ -130,7 +92,6 @@ func (m *Middleware) forwardedClientAddr(
 			return addr, true
 		}
 	}
-	}
 
 	return netip.Addr{}, false
 }
@@ -152,10 +113,8 @@ func (m *Middleware) clientKey(r *http.Request) string {
 	peer, err := netip.ParseAddr(ipFromHostPort(r.RemoteAddr))
 	if err != nil {
 		// Not an address we can reason about; key on the raw
-		// value, the most specific identity left. On a
+		// value rather than collapsing such peers into one
-		// Unix-socket listener every peer carries the same
+		// shared bucket.
-		// RemoteAddr and so shares one bucket, which is the
-		// fail-closed direction.
 		return r.RemoteAddr
 	}
 
@@ -251,26 +210,15 @@ func (m *Middleware) postRateLimit(
 	}
 }
 
-// ReceiverRateLimit returns middleware that rate-limits the public
+// ReceiverRateLimit returns middleware that rate-limits the
-// webhook receiver endpoint with two limits in series.
+// public webhook receiver endpoint per client IP per request
-//
+// path (the path contains the entrypoint UUID, so each sender
-// The inner limit is per client IP per request path: the path
+// is limited per entrypoint without affecting other senders or
-// contains the entrypoint UUID, so each sender is limited per
+// other entrypoints). The limit is Config.ReceiverRateLimit
-// entrypoint without affecting other senders or other entrypoints.
+// requests per minute. Requests over the limit receive a 429.
-// It is Config.ReceiverRateLimit requests per minute.
+// Clients are identified by rateLimitKey.
-//
-// That limit alone bounds nothing in aggregate. The route pattern
-// /webhook/{uuid} matches any single segment, so a client that
-// invents a fresh path per request mints a fresh bucket per request
-// and never refills one — and every such request still reaches the
-// handler's entrypoint lookup before it 404s. The outer limit is
-// therefore keyed on the client IP alone, capping what one address
-// can spend across the whole route however it varies the path.
-//
-// Requests over either limit receive a 429. Clients are identified
-// by rateLimitKey.
 func (m *Middleware) ReceiverRateLimit() func(http.Handler) http.Handler {
-	perEntrypoint := httprate.Limit(
+	return httprate.Limit(
 		m.params.Config.ReceiverRateLimit,
 		receiverRateInterval,
 		httprate.WithKeyFuncs(
@@ -282,31 +230,4 @@ func (m *Middleware) ReceiverRateLimit() func(http.Handler) http.Handler {
 			"Too many requests. Please slow down.",
 		)),
 	)
-
-	aggregate := httprate.Limit(
-		receiverAggregateLimit(m.params.Config.ReceiverRateLimit),
-		receiverRateInterval,
-		httprate.WithKeyFuncs(m.rateLimitKey),
-		httprate.WithLimitHandler(m.tooManyRequests(
-			"webhook receiver aggregate rate limit exceeded",
-			"Too many requests. Please slow down.",
-		)),
-	)
-
-	return func(next http.Handler) http.Handler {
-		return aggregate(perEntrypoint(next))
-	}
-}
-
-// receiverAggregateLimit is the per-IP aggregate limit derived from
-// the configured per-entrypoint limit. The operator sets the latter
-// and nothing bounds it from above, so the multiplication is
-// saturated rather than allowed to wrap into a negative limit that
-// would reject every request.
-func receiverAggregateLimit(perEntrypoint int) int {
-	if perEntrypoint > math.MaxInt/receiverAggregateMultiplier {
-		return math.MaxInt
-	}
-
-	return perEntrypoint * receiverAggregateMultiplier
 }

internal/middleware/ratelimit_test.go

@@ -4,15 +4,11 @@ import (
 	"context"
 	"fmt"
 	"log/slog"
-	"math"
 	"net/http"
 	"net/http/httptest"
 	"net/netip"
 	"os"
-	"runtime"
-	"strings"
 	"testing"
-	"time"
 
 	"github.com/stretchr/testify/assert"
 	"sneak.berlin/go/webhooker/internal/config"
@@ -572,176 +568,6 @@ func TestRateLimitKey_ChainWalkSkipsClientPrepended(t *testing.T) {
 	)
 }
 
-// TestRateLimitKey_LongChainCapsWalkAndFallsBackToPeer covers the
-// hop-walk cap. A client behind the trusted proxy can pad
-// X-Forwarded-For with tens of thousands of trusted-looking hops,
-// which costs a walk proportional to the padding and, once the walk
-// runs off the left end of the chain, reaches the entry the client
-// put there. Capping the walk stops both: the key falls back to the
-// peer address, so rotating the head of the chain mints no bucket,
-// and the run does not scale with the chain length.
-func TestRateLimitKey_LongChainCapsWalkAndFallsBackToPeer(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	// 50k hops is roughly 0.9 MB, within the default
-	// MaxHeaderBytes.
-	const hops = 50000
-
-	padding := strings.Repeat(", 10.0.0.2", hops-1)
-
-	start := time.Now()
-
-	assertSharedBucket(
-		t, trustedProxies("10.0.0.0/8"), "10.0.0.1:44444",
-		func(i int) map[string]string {
-			return map[string]string{
-				headerXFF: fmt.Sprintf("9.9.9.%d%s", i+1, padding),
-			}
-		},
-		"a padded X-Forwarded-For chain must fall back to the "+
-			"peer address, not reach the client-controlled entry "+
-			"at the head of the chain",
-	)
-
-	assert.Less(
-		t, time.Since(start), 2*time.Second,
-		"the capped walk must not scale with the chain length",
-	)
-}
-
-// TestRateLimitKey_LongChainAllocationIsBounded is the allocation
-// half of the hop cap. Capping the walk still left every request
-// paying for the whole header the client sent, because the chain was
-// split before it was capped: about 8 MB of []string for the 1 MB a
-// default MaxHeaderBytes allows, on the unauthenticated receiver.
-//
-// Bytes are the measurement, not allocation count: strings.Split of a
-// 1 MB chain is a single allocation, so testing.AllocsPerRun scores
-// it as cheap. The test is deliberately sequential — it reads
-// process-wide counters, and Go runs this package's parallel tests
-// only after the sequential ones finish.
-//
-//nolint:paralleltest // reads process-wide allocation counters
-func TestRateLimitKey_LongChainAllocationIsBounded(t *testing.T) {
-	// 100k hops of ", 10.0.0.2" is roughly 1 MB.
-	const (
-		hops            = 100000
-		iterations      = 50
-		maxBytesPerCall = 4096
-	)
-
-	m := rateLimitMiddleware(t, &config.Config{
-		TrustedProxies: trustedProxies("10.0.0.0/8"),
-	})
-
-	req := httptest.NewRequestWithContext(
-		context.Background(), http.MethodPost, loginPath, nil,
-	)
-	req.RemoteAddr = "10.0.0.1:44444"
-	req.Header.Set(
-		headerXFF, "9.9.9.9"+strings.Repeat(", 10.0.0.2", hops),
-	)
-
-	var before, after runtime.MemStats
-
-	var key string
-
-	runtime.ReadMemStats(&before)
-
-	for range iterations {
-		key = middleware.ClientKeyForTest(m, req)
-	}
-
-	runtime.ReadMemStats(&after)
-
-	perCall := (after.TotalAlloc - before.TotalAlloc) / iterations
-
-	assert.Less(
-		t, perCall, uint64(maxBytesPerCall),
-		"a %d-byte X-Forwarded-For must not allocate in proportion "+
-			"to its length, but cost %d bytes per call",
-		len(req.Header.Get(headerXFF)), perCall,
-	)
-
-	assert.Equal(
-		t, "10.0.0.1", key,
-		"the padded chain must still fall back to the peer address",
-	)
-}
-
-// TestReceiverRateLimit_LimitsAggregateAcrossInventedPaths is the
-// regression test for the per-path bucket key. The route pattern
-// matches any single segment, so a client that never reuses a path
-// never reuses a per-entrypoint bucket either, and its aggregate
-// rate against the receiver is whatever it likes — with every
-// request reaching an entrypoint lookup before it 404s. The IP-only
-// aggregate limiter is what bounds that, so this must fail if the
-// aggregate limiter is removed.
-func TestReceiverRateLimit_LimitsAggregateAcrossInventedPaths(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	const (
-		limit = 3
-		ip    = "6.6.6.6:1234"
-	)
-
-	aggregate := limit * middleware.ReceiverAggregateMultiplierConst
-
-	handler := receiverLimitedHandler(t, limit)
-
-	// Every request goes to a path this client has never used, so
-	// none of them shares a per-entrypoint bucket with another.
-	for i := range aggregate {
-		w := receiverPost(
-			handler, ip, fmt.Sprintf("/webhook/invented-%d", i),
-		)
-		assert.Equal(
-			t, http.StatusOK, w.Code,
-			"request %d to a distinct path should pass", i,
-		)
-	}
-
-	w := receiverPost(
-		handler, ip, fmt.Sprintf("/webhook/invented-%d", aggregate),
-	)
-	assert.Equal(
-		t, http.StatusTooManyRequests, w.Code,
-		"a client must not be able to raise its aggregate rate "+
-			"against /webhook/* by varying the path",
-	)
-
-	// The aggregate limit is still per client IP: exhausting one
-	// address must not throttle another.
-	w = receiverPost(handler, "6.6.6.7:1234", "/webhook/invented-0")
-	assert.Equal(
-		t, http.StatusOK, w.Code,
-		"a different client IP must not be affected",
-	)
-}
-
-// TestReceiverAggregateLimit_SaturatesOnOverflow covers the derived
-// aggregate limit for a configured per-entrypoint limit large enough
-// that multiplying it would wrap negative, which httprate would read
-// as a limit that rejects every request.
-func TestReceiverAggregateLimit_SaturatesOnOverflow(t *testing.T) {
-	t.Parallel()
-
-	assert.Equal(
-		t, 1200,
-		middleware.ReceiverAggregateLimitForTest(120),
-		"the default limit scales by the multiplier",
-	)
-	assert.Equal(
-		t, math.MaxInt,
-		middleware.ReceiverAggregateLimitForTest(math.MaxInt),
-		"an overflowing limit saturates instead of wrapping",
-	)
-}
-
 // TestReceiverRateLimit_IgnoresForwardedFromUntrustedPeer proves
 // the receiver limiter uses the same gated key function as the
 // POST limiters.