Leave a delivery cut off by a stop for the next start (closes #527)

Stopping the engine cancels the context every http and slack request is
sent with. An attempt cut off that way was recorded as failed, which for
a target with no retries, or on a last retry, ended the delivery failed
and nothing sent it again.

The shared retry core now records nothing for a failed attempt when the
engine's context is cancelled: no result, no circuit breaker outcome, no
status change, no count in the attempt metrics. The delivery stays
pending or retrying and startup recovery sends it again. A target's own
timeout is still a failed attempt. The README says what happens to an
attempt in flight at a stop and no longer claims every attempt is
recorded.

Model: opus-5-5

Dockerfile

@@ -214,16 +214,22 @@ RUN version="$(make version VERSION="$VERSION")"; \
 # (Alpine.js, extracted from its tarball in 3p/) first.
 RUN make build VERSION="$VERSION"
 
-# Rebuild with static linking for Alpine runtime.
+# Rebuild with static linking for the Alpine runtime. The cgo binary the
-# make build already verified compilation.
+# step above builds is dynamically linked against glibc, which Alpine
-# The CGO binary from `make build` is dynamically linked against glibc,
+# (musl) does not have.
-# which doesn't exist on Alpine (musl). Rebuild with static linking so
-# the binary runs on Alpine without glibc.
 #
-# The static flags go in through GO_LDFLAGS rather than a -ldflags of
+# A statically linked glibc still loads shared libraries at run time for
-# their own: the build target composes them with the -X that stamps the
+# getaddrinfo and dlopen, and Alpine has none to load, so the build tags
-# version, so this relink cannot silently drop the stamp.
+# keep both out of the binary: netgo and osusergo select Go's own DNS
-RUN CGO_ENABLED=1 make build VERSION="$VERSION" GO_LDFLAGS='-extldflags "-static"'
+# resolver and user lookup instead of glibc's, and
+# sqlite_omit_load_extension leaves out SQLite extension loading, which
+# webhooker never uses.
+#
+# The static flags and tags go in through GO_LDFLAGS and GO_TAGS rather
+# than a -ldflags of their own: the build target composes them with the
+# -X that stamps the version, so this relink cannot silently drop the
+# stamp.
+RUN CGO_ENABLED=1 make build VERSION="$VERSION" GO_TAGS=netgo,osusergo,sqlite_omit_load_extension GO_LDFLAGS='-extldflags "-static"'
 
 # Runtime stage
 # alpine:3.21, 2026-03-17

Makefile

@@ -16,14 +16,16 @@ VERSION ?= $(shell script/version)
 # exists to correct.
 override VERSION := $(or $(strip $(VERSION)),$(shell script/version))
 
-# Extra linker flags for the build target. The static relink in the
+# Extra linker flags and build tags for the build target. The static
-# Dockerfile adds -extldflags here rather than passing its own -ldflags,
+# relink in the Dockerfile passes -extldflags and its build tags through
-# so composing flags cannot drop the version stamp.
+# these rather than a -ldflags of its own, so composing flags cannot drop
+# the version stamp.
 #
 # The build target itself always passes -trimpath and -s -w, as the Go
 # Dockerfile in REPO_POLICIES.md does: no build paths, symbol table or
 # debug information in the binary.
 GO_LDFLAGS ?=
+GO_TAGS ?=
 
 bootstrap:
 	@script/bootstrap
@@ -53,7 +55,7 @@ check:
 	@script/check
 
 build: assets
-	go build -trimpath -ldflags '$(strip -s -w -X main.version=$(VERSION) $(GO_LDFLAGS))' -o bin/webhooker ./cmd/webhooker
+	go build -trimpath -tags '$(GO_TAGS)' -ldflags '$(strip -s -w -X main.version=$(VERSION) $(GO_LDFLAGS))' -o bin/webhooker ./cmd/webhooker
 
 run: build
 	./bin/webhooker

README.md

@@ -465,10 +465,7 @@ idle timestamp is rewritten at most once per tenth of the idle window rather
 than on every request, which means a session may expire up to 10% early relative
 to the user's true last request, but never late.
 
-Both clocks are anchored by timestamps stored in the session cookie. Sessions
+Both clocks are anchored by timestamps stored in the session cookie.
-issued before this feature existed carry neither, so they are treated as
-expired: upgrading to a build that has it logs every existing session out once,
-and those users sign in again.
 
 #### Invalid values abort startup
 
@@ -702,11 +699,11 @@ app as that user.
 `webhooker.db` holds target configuration in plaintext — bearer tokens, API
 keys, Slack webhook URLs — along with the session encryption key, so webhooker
 creates every SQLite file it owns `0600`: each database and both of its `-wal`
-and `-shm` sidecars, across all three tiers. Files an earlier build left `0644`
+and `-shm` sidecars, across all three tiers. Any of them found at another mode
-are tightened when they are opened. The directory's `0750` is defence in depth —
+is set to `0600` when the database is opened. The directory's `0750` is defence
-it stops other local users listing the directory and learning your webhook UUIDs
+in depth — it stops other local users listing the directory and learning your
-from the `events-{uuid}.db` filenames — not the barrier protecting the
+webhook UUIDs from the `events-{uuid}.db` filenames — not the barrier protecting
-credentials.
+the credentials.
 
 ### Running under upaas
 
@@ -918,7 +915,7 @@ replaces the `max-age` it stored, so to end the policy sooner, set a short
 `HSTS_MAX_AGE` such as `1s` and keep it until returning browsers have picked it
 up, or have a reverse proxy send `max-age=0`.
 
-## Backup, Restore, and Upgrades
+## Backup and Restore
 
 ### What to back up
 
@@ -1071,60 +1068,14 @@ beside it, or wait until there are none.
 
 4. Start the service. The container gives the directory and the restored files
    to the `webhooker` user before the app starts, whoever restored them (see
-   [Running with Docker](#running-with-docker)). Each restored database gets any
+   [Running with Docker](#running-with-docker)).
-   of its SQL migrations it has not had as it is opened (see
-   [Upgrades](#upgrades)).
-
-### Upgrades
-
-**Back up before every upgrade.** Each kind of database file has its schema in
-SQL files built into the binary, one directory per kind under
-`internal/db/migrations/`. In each, `000_migration.sql` creates the
-`schema_migrations` table, which records the number of every file the database
-has had, and `001_schema.sql` holds the whole schema. Opening a database runs,
-in one transaction, every file in its directory that `schema_migrations` does
-not list:
-
-- `main/` for the main database, on connect — settings, users, API keys,
-  webhooks, entrypoints and targets
-- `events/` for each event database, when it is lazily opened — events,
-  deliveries, delivery results and their running totals
-- `archive/` for each archive database, on every open and reopen
-
-There are no down migrations.
-
-Upgrade procedure:
-
-1. Stop the service.
-2. Back up `DATA_DIR` using one of the procedures above.
-3. Pull the new image and start it.
-4. Confirm `database migrations completed` in the logs before putting traffic
-   back on it.
-5. Confirm the new build is the one running:
-   `curl -s http://host:8080/.well-known/healthcheck` reports the version it was
-   stamped with (see [Version stamping](#version-stamping)).
-
-**Upgrading past the introduction of `BIND_ADDRESS`:** earlier versions always
-bound every interface. **Container deployments are unaffected** — the image
-ships `ENV BIND_ADDRESS=0.0.0.0`, so a `docker run` or Compose service that
-worked before still works with nothing changed.
-
-A **bare binary** is the case that changes: the listener now binds `127.0.0.1`
-unless `BIND_ADDRESS` says otherwise, so a deployment that relied on reaching it
-from another host becomes unreachable until it sets the address the proxy
-connects to. Check the `bindAddress` field of the startup log to see what a
-running process bound. See [Bind address](#bind-address).
-
-**Downgrade is unsupported.** Once a newer binary has migrated the files there
-is no way to move them back. The only supported way back to an older version is
-restoring the pre-upgrade backup, which discards everything received since that
-backup was taken.
 
 ### Version stamping
 
 The binary reports its version at `/.well-known/healthcheck` (the `version`
 field), in the UI footer, and in the startup log line (`msg=starting`,
 `version=...`). It is also the Sentry release name, as `webhooker-{version}`.
+`curl -s http://host:8080/.well-known/healthcheck` shows which build is running.
 The value is stamped in at build time by the linker; it is not read from a file
 at runtime, so it identifies the build itself.
 
@@ -1366,20 +1317,22 @@ webhooker solves this by acting as a durable intermediary:
    nothing is lost if downstream targets are unavailable.
 
 2. **Guaranteed delivery** — Events are queued for delivery to each configured
-   target. Failed deliveries are retried with configurable backoff. Every
+   target. Failed deliveries are retried with configurable backoff. Delivery
-   delivery attempt is logged with status codes, response bodies, and timing.
+   attempts are logged with status codes, response bodies, and timing.
 
     **That guarantee is at-least-once, not exactly-once.** When a send reaches
     its target but the write recording that outcome fails, the delivery is
     deliberately left in a recoverable state rather than marked done — losing a
     delivery is the worse failure — so the pending sweep picks it up about
     fifteen minutes later, or the next restart does, and the target receives a
-    payload it already got. webhooker adds no delivery identifier of its own to
+    payload it already got. A send still in flight when the service stops is
-    an outbound request, so **make your receiver idempotent** against whatever
+    left the same way: its attempt is not recorded, and the next start sends it
-    the payload itself carries.
+    again (see Shutdown). webhooker adds no delivery identifier of its own to an
+    outbound request, so **make your receiver idempotent** against whatever the
+    payload itself carries.
 
 3. **Observability** — Full request/response logging for every webhook received
-   and every delivery attempted. Prometheus metrics expose volume, latency, and
+   and for delivery attempts. Prometheus metrics expose volume, latency, and
    error rates. The web UI provides real-time visibility into event flow.
 
 4. **Fan-out** — A single incoming webhook can be delivered to multiple targets
@@ -1583,8 +1536,7 @@ The cap is not arbitrary: the reaper computes its cutoff as a `time.Duration`,
 an int64 nanosecond count, and a longer period overflows it. An overflowed
 cutoff lands in the future, where it matches every row, so the sweep would
 delete every event the webhook has instead of none. The reaper also clamps the
-value it is given, so a row written by an older version cannot trigger that
+value it reads to the cap, so no stored value can trigger that either.
-either.
 
 #### Entrypoint
 
@@ -1818,7 +1770,7 @@ is what bounds it.
 #### DeliveryResult
 
 The result of a single delivery attempt. Every attempt (including retries) is
-individually logged for full observability.
+individually logged, except one cut off by a stop (see Shutdown).
 
 | Field           | Type    | Description                               |
 | --------------- | ------- | ----------------------------------------- |
@@ -1967,7 +1919,7 @@ and application state:
 - **APIKeys** — programmatic access credentials
 
 On first startup the main database is created from its SQL files (see
-[Upgrades](#upgrades)), a session encryption key is generated and stored, and an
+[Schema](#schema)), a session encryption key is generated and stored, and an
 `admin` user is created.
 
 **Per-Webhook Event Databases** (`{DATA_DIR}/events-{webhook_uuid}.db`) — each
@@ -2164,6 +2116,21 @@ The database uses the
 though CGO is required at build time due to the transitive `mattn/go-sqlite3`
 dependency from `gorm.io/driver/sqlite`.
 
+#### Schema
+
+Each kind of database file has its schema in SQL files built into the binary,
+one directory per kind under `internal/db/migrations/`. In each,
+`000_migration.sql` creates the `schema_migrations` table, which records the
+number of every file the database has had, and `001_schema.sql` holds the whole
+schema. Opening a database runs, in one transaction, every file in its directory
+that `schema_migrations` does not list:
+
+- `main/` for the main database, on connect — settings, users, API keys,
+  webhooks, entrypoints and targets
+- `events/` for each event database, when it is lazily opened — events,
+  deliveries, delivery results and their running totals
+- `archive/` for each archive database, on every open and reopen
+
 ### Request Flow
 
 ```
@@ -2241,12 +2208,16 @@ This means:
   buffer rather than spawning more goroutines.
 - **Independent results** — each worker records its own delivery result in the
   per-webhook database without coordination.
-- **Graceful shutdown** — cancel the context, workers finish their current task
+- **Graceful shutdown** — the stop hook cancels the workers' context. A worker
-  and exit. The stop hook waits for the pool via `lifecycle.WaitForShutdown`,
+  may still take tasks already queued before it exits. An `http` or `slack`
-  which bounds that wait by fx's stop timeout rather than blocking forever on a
+  request in flight is cut off, and one started after the cancel fails at once.
-  wedged worker. On timeout it logs at `ERROR` and returns an error, and the
+  Neither is recorded or counted in the metrics, and the next start sends the
-  goroutines that did not finish are still running — an unclean shutdown is
+  delivery again (see Shutdown). A `database` or `log` task runs as normal. The
-  reported rather than hidden.
+  stop hook waits for the pool via `lifecycle.WaitForShutdown`, which bounds
+  that wait by fx's stop timeout rather than blocking forever on a wedged
+  worker. On timeout it logs at `ERROR` and returns an error, and the goroutines
+  that did not finish are still running — an unclean shutdown is reported rather
+  than hidden.
 
 **Recovery paths:**
 
@@ -2352,7 +2323,7 @@ getting anywhere.
 | Metric                                 | Type      | Meaning                                                                                                                                                                                                                                                                                                   |
 | -------------------------------------- | --------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `webhooker_events_received_total`      | counter   | Events received and durably stored. Compare against the delivery counters on one dashboard                                                                                                                                                                                                                |
-| `webhooker_delivery_attempts_total`    | counter   | Delivery attempts actually dispatched to a target. A delivery a circuit breaker refused is not one: it is counted as a retry instead, but only when the refusal moves it into `retrying`                                                                                                                  |
+| `webhooker_delivery_attempts_total`    | counter   | Delivery attempts actually dispatched to a target. A delivery a circuit breaker refused is not one: it is counted as a retry instead, but only when the refusal moves it into `retrying`. An attempt cut off by a stop is not counted (see Shutdown)                                                      |
 | `webhooker_deliveries_succeeded_total` | counter   | Deliveries that reached `delivered`                                                                                                                                                                                                                                                                       |
 | `webhooker_deliveries_failed_total`    | counter   | Deliveries that failed terminally and will not be retried                                                                                                                                                                                                                                                 |
 | `webhooker_delivery_retries_total`     | counter   | Deliveries put back into `retrying`                                                                                                                                                                                                                                                                       |
@@ -3319,7 +3290,8 @@ stop-hook log:
 3. `server` — the HTTP drain, bounded by `server.ShutdownTimeout` (**3
    seconds**) and by what the hooks before it left, then a Sentry flush if
    `SENTRY_DSN` is set
-4. `delivery.Engine` — waits for its workers, then closes the archive databases
+4. `delivery.Engine` — cuts off any `http` or `slack` request in flight, waits
+   for its workers, then closes the archive databases
 5. `healthcheck`
 6. `WebhookDBManager`
 7. the database close
@@ -3330,6 +3302,12 @@ by the stop context, so a wedge there consumes the 5 seconds before the HTTP
 server hook is ever entered. The hooks after the server are microsecond-scale in
 normal operation.
 
+The delivery engine cancels a delivery request in flight. That attempt is not
+recorded or counted in the metrics, and the delivery keeps its `pending` or
+`retrying` status, so startup recovery sends it again on the next start (see
+Recovery paths under Bounded Worker Pool). If the receiver already had it, it
+receives it twice: the at-least-once duplicate described under Rationale.
+
 The HTTP drain budget is deliberately **shorter** than the sequence budget. Were
 the two equal, a drain that used its whole budget would exhaust the sequence
 budget at the instant it finished, and every later hook — the delivery engine,
@@ -3454,12 +3432,14 @@ fixed independently of the compiler's:
    phases and the `css-check` and `markdown-check` stages passing (it copies a
    file from each), runs `make build` (which extracts Alpine.js from `3p/`
    first), and then rebuilds the binary with `CGO_ENABLED=1` and static linking
-   so it runs on musl. Both builds go through `make build`, the relink adding
+   so it runs on musl, with the build tags `netgo`, `osusergo` and
-   its `-extldflags` via `GO_LDFLAGS`, so neither can drop the `-X` that stamps
+   `sqlite_omit_load_extension` so it needs none of glibc's shared libraries at
-   the version. The version is the `VERSION` build arg if one is given,
+   run time. Both builds go through `make build`, the relink adding its
-   otherwise derived from the `.git` in the context, and the stage fails if a
+   `-extldflags` via `GO_LDFLAGS` and its tags via `GO_TAGS`, so neither can
-   context with `.git` would stamp an empty version, `dev` or `unknown` (see
+   drop the `-X` that stamps the version. The version is the `VERSION` build arg
-   [Version stamping](#version-stamping)).
+   if one is given, otherwise derived from the `.git` in the context, and the
+   stage fails if a context with `.git` would stamp an empty version, `dev` or
+   `unknown` (see [Version stamping](#version-stamping)).
 7. **Runtime stage** (`alpine:3.21`) — copies the static binary and
    `deploy/docker-entrypoint.sh`, creates the `/var/lib/webhooker` directory for
    all SQLite databases, exposes port 8080, and includes a health check against

internal/database/model_event.go

@@ -45,8 +45,7 @@ type Event struct {
 
 	// 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
+	// the receiver. It is not a foreign key: the source event can be
-	// existed. It is not a foreign key: the source event can be
 	// reaped by retention while its copies remain, and the id is
 	// kept as the record of where the copy came from either way.
 	ResubmittedFromID *string `gorm:"type:uuid;index:idx_events_resubmitted_from_id,priority:1;index:idx_events_entrypoint_id,priority:3" json:"resubmittedFromId,omitempty"`

internal/database/model_webhook.go

@@ -82,7 +82,7 @@ type Webhook struct {
 // value while building the insert statement, which runs after
 // BeforeSave; rewriting any later than this loses that race and the
 // row lands at 30 days. Living on the model also means a future call
-// site — a REST API, a fixture, a migration — cannot bypass it.
+// site, such as a REST API or a fixture, cannot bypass it.
 func (w *Webhook) BeforeSave(_ *gorm.DB) error {
 	if w.RetentionDays <= 0 {
 		w.RetentionDays = RetentionForeverDays
@@ -98,8 +98,8 @@ func (w *Webhook) BeforeSave(_ *gorm.DB) error {
 // are exempt from reaping.
 //
 // It accepts the RetentionForeverDays sentinel written by BeforeSave
-// and, defensively, the non-positive values that rows written before
+// and, defensively, any non-positive value, which BeforeSave treats
-// the sentinel existed may still carry.
+// as a request to retain forever.
 func retainsForever(retentionDays int) bool {
 	return retentionDays <= 0 ||
 		retentionDays >= RetentionForeverDays

internal/database/retention.go

@@ -253,7 +253,7 @@ func (r *RetentionReaper) reapWebhook(
 // row in the database: the sweep then deletes every event, delivery,
 // and delivery result, including ones created seconds ago. Rejecting
 // out-of-range input at the form is the primary guard; saturating here
-// means an old row, a migration, or a future call site cannot turn a
+// means a value that reaches the row by any other path cannot turn a
 // too-large retention into total data loss.
 func retentionCutoff(
 	now time.Time,

internal/database/sqlite_open.go

@@ -118,9 +118,8 @@ const SQLiteFilePerm fs.FileMode = 0o600
 // SQLite still reports the absence rather than this function
 // materializing an empty database the caller asked not to create.
 //
-// Chmod of a file that already exists is what tightens a data
+// The mode is set on every open, whoever created the file, so a
-// directory an earlier build left at 0644 — including a developer's
+// database or sidecar found at a wider mode is tightened too.
-// own scratch directory — without any migration machinery.
 func reserveSQLiteFile(path string, create bool) error {
 	if create {
 		// gosec G304: the path is the database file the caller asked
@@ -242,7 +241,19 @@ func SQLiteDSN(path, mode string) string {
 	)
 	q.Add("_pragma", "journal_mode(WAL)")
 
-	return "file:" + path + "?" + q.Encode()
+	// SQLite reads a file: URI's path only up to the first ? or #, and
+	// decodes %XX escapes in it, so url.URL escapes the path. OmitHost
+	// keeps a relative path as "file:data/x.db"; written
+	// "file://data/x.db", SQLite would reject "data" as the URI's
+	// authority.
+	dsn := url.URL{
+		Scheme:   "file",
+		Path:     path,
+		OmitHost: true,
+		RawQuery: q.Encode(),
+	}
+
+	return dsn.String()
 }
 
 // OpenSQLite opens the SQLite file at path with the service's

internal/database/sqlite_open_test.go

@@ -2,6 +2,8 @@ package database_test
 
 import (
 	"context"
+	"database/sql"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -112,6 +114,79 @@ func TestMainDBAppliesPragmasOnALiveHandle(t *testing.T) {
 	assert.Equal(t, "10000", busy)
 }
 
+// TestOpenSQLiteOpensThePathAskedFor uses a data directory whose name
+// holds ?, # and %. SQLite reads a file: URI's path only up to a ? or
+// #, and decodes %41 to A, so an unescaped path sent every database in
+// that directory to one file outside it.
+func TestOpenSQLiteOpensThePathAskedFor(t *testing.T) {
+	t.Parallel()
+
+	dir := filepath.Join(t.TempDir(), "hooks#1?x%41")
+	require.NoError(t, os.Mkdir(dir, 0o700))
+
+	for _, name := range []string{
+		database.MainDBFileName,
+		"events-" + uuid.New().String() + ".db",
+	} {
+		path := filepath.Join(dir, name)
+
+		sqlDB, err := database.OpenSQLite(
+			path, database.SQLiteModeCreate,
+		)
+		require.NoError(t, err)
+
+		t.Cleanup(func() { assert.NoError(t, sqlDB.Close()) })
+
+		assertOpenedFile(t, sqlDB, path)
+	}
+}
+
+// TestOpenSQLiteOpensARelativePath opens a database at a path relative
+// to the working directory, which is what a relative DATA_DIR such as
+// the README's DATA_DIR=../webhooker-data gives OpenSQLite.
+//
+//nolint:paralleltest // t.Chdir moves the whole process.
+func TestOpenSQLiteOpensARelativePath(t *testing.T) {
+	t.Chdir(t.TempDir())
+	require.NoError(t, os.Mkdir("data", 0o700))
+
+	path := filepath.Join("data", database.MainDBFileName)
+
+	sqlDB, err := database.OpenSQLite(path, database.SQLiteModeCreate)
+	require.NoError(t, err)
+
+	defer func() { require.NoError(t, sqlDB.Close()) }()
+
+	assertOpenedFile(t, sqlDB, path)
+}
+
+// assertOpenedFile checks that sqlDB is the SQLite file at path.
+// database_list names the file SQLite actually opened, as an absolute
+// path with symlinks resolved, so the files are compared, not the names.
+func assertOpenedFile(t *testing.T, sqlDB *sql.DB, path string) {
+	t.Helper()
+
+	var (
+		seq          int
+		schema, file string
+	)
+
+	require.NoError(t, sqlDB.
+		QueryRowContext(t.Context(), "pragma database_list").
+		Scan(&seq, &schema, &file))
+
+	asked, err := os.Stat(path)
+	require.NoError(t, err)
+
+	opened, err := os.Stat(file)
+	require.NoError(t, err)
+
+	assert.True(
+		t, os.SameFile(asked, opened),
+		"asked for %s, SQLite opened %s", path, file,
+	)
+}
+
 // TestConcurrentReaderDoesNotBlockWrites is the unit-scale form of the
 // reproduction in
 // https://git.eeqj.de/sneak/webhooker/issues/256: an operator's

internal/delivery/archive_sweeper.go

@@ -201,8 +201,7 @@ func (s *ArchiveSweeper) sweep(ctx context.Context) {
 
 // sweepTarget prunes the archive of a single database target.
 // A missing, empty, or "never" expiry parses as a zero duration
-// and is skipped entirely, so those archives keep exactly the
+// and is skipped entirely, so those archives are never pruned.
-// behaviour they had before the sweep existed.
 func (s *ArchiveSweeper) sweepTarget(target *database.Target) {
 	expiry, err := parseArchiveExpiry(target.Config)
 	if err != nil {

internal/delivery/delivery_totals_test.go

@@ -32,8 +32,9 @@ func targetTotals(
 
 // TestUpdateDeliveryStatus_FinishTimeAndTargetTotals pins what a status
 // write records for the webhook page's statistics: the time a delivery
-// finished, set only when it becomes delivered or failed, and one more
+// finished, set only when it becomes delivered or failed and stored in
-// on its target's delivered or failed total.
+// the same form as created_at, and one more on its target's delivered
+// or failed total.
 func TestUpdateDeliveryStatus_FinishTimeAndTargetTotals(t *testing.T) {
 	t.Parallel()
 
@@ -75,6 +76,16 @@ func TestUpdateDeliveryStatus_FinishTimeAndTargetTotals(t *testing.T) {
 			if tt.finished {
 				require.NotNil(t, stored.FinishedAt)
 				assert.False(t, stored.FinishedAt.Before(before))
+
+				var createdAt, finishedAt string
+
+				require.NoError(t, db.Raw(
+					`SELECT CAST(created_at AS TEXT),
+						CAST(finished_at AS TEXT)
+					FROM deliveries WHERE id = ?`, d.ID,
+				).Row().Scan(&createdAt, &finishedAt))
+				assertStoredTime(t, createdAt)
+				assertStoredTime(t, finishedAt)
 			} else {
 				assert.Nil(t, stored.FinishedAt)
 			}

internal/delivery/engine.go

@@ -1701,8 +1701,11 @@ func writeDeliveryStatus(
 			database.DeliveryStatusFailed,
 		}).
 		Updates(map[string]any{
-			"status":      status,
+			"status": status,
-			"finished_at": time.Now(),
+			// GORM's clock, the one that stamps created_at. A bare
+			// time.Now() carries a monotonic clock reading, which the
+			// driver would store as an " m=+…" suffix.
+			"finished_at": tx.NowFunc(),
 		})
 	if res.Error != nil || res.RowsAffected == 0 {
 		return res.Error
@@ -1906,12 +1909,13 @@ func (e *Engine) takeForRedispatch(
 		return false
 	}
 
+	// GORM's clock, as writeDeliveryStatus explains.
 	res := webhookDB.
 		Model(&database.Delivery{}).
 		Where(
 			"id = ? AND status = ?", deliveryID, eligible,
 		).
-		UpdateColumn("updated_at", time.Now())
+		UpdateColumn("updated_at", webhookDB.NowFunc())
 
 	if res.Error != nil {
 		e.log.Error(

internal/delivery/engine_lifecycle_test.go

@@ -2,11 +2,16 @@ package delivery_test
 
 import (
 	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
 	"path/filepath"
+	"sync"
 	"testing"
 	"time"
 
 	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/fx"
 	"gorm.io/gorm/clause"
@@ -272,6 +277,154 @@ func TestEngine_StopHookHonoursStopTimeout(t *testing.T) {
 	requireStopHookExpires(t, lc.hooks[0], "delivery engine")
 }
 
+// seedHeldDelivery gives the setup's webhook an http target with
+// maxRetries, pointed at a receiver that keeps every request open until
+// the client gives up on it, and seeds one delivery to that target at
+// status. It returns the task that sends attempt attemptNum of the
+// delivery, and a channel that is closed when a request reaches the
+// receiver.
+func seedHeldDelivery(
+	t *testing.T,
+	s iSetup,
+	maxRetries int,
+	status database.DeliveryStatus,
+	attemptNum int,
+) (delivery.Task, <-chan struct{}) {
+	t.Helper()
+
+	arrived := make(chan struct{})
+
+	var once sync.Once
+
+	ts := httptest.NewServer(http.HandlerFunc(
+		func(_ http.ResponseWriter, r *http.Request) {
+			// The server notices the client hanging up only once the
+			// body has been read; until then r.Context() never ends.
+			_, _ = io.Copy(io.Discard, r.Body)
+
+			once.Do(func() { close(arrived) })
+
+			<-r.Context().Done()
+		},
+	))
+	t.Cleanup(ts.Close)
+
+	cfg := iHTTPConfig(ts.URL)
+	targetID := uuid.New().String()
+
+	iCreateWebhook(t, s.MainDB, s.WebhookID, "hook")
+	iCreateTarget(
+		t, s.MainDB, targetID, s.WebhookID, "held",
+		database.TargetTypeHTTP, cfg, maxRetries,
+	)
+
+	event := iSeedEvent(t, s.WebhookDB, s.WebhookID, `{"held":true}`)
+	d := iSeedDelivery(t, s.WebhookDB, event.ID, targetID, status)
+
+	bodyStr := event.Body
+
+	return iTask(
+		d, event, s.WebhookID, targetID, "held", cfg,
+		maxRetries, attemptNum, &bodyStr,
+	), arrived
+}
+
+// stopDuringAttempt waits until the receiver holds an attempt open, then
+// stops the engine through its real stop hook.
+func stopDuringAttempt(
+	t *testing.T, lc *recordingLifecycle, arrived <-chan struct{},
+) {
+	t.Helper()
+
+	select {
+	case <-arrived:
+	case <-time.After(5 * time.Second):
+		t.Fatal("the delivery attempt never reached the receiver")
+	}
+
+	require.NoError(t, lc.hooks[0].OnStop(context.Background()))
+}
+
+// requireRequeued runs restart recovery on the stopped engine and
+// requires it to queue task's attempt again on ch.
+func requireRequeued(
+	t *testing.T, s iSetup, ch <-chan delivery.Task, task delivery.Task,
+) {
+	t.Helper()
+
+	s.Engine.ExportRecoverWebhookDeliveries(
+		context.Background(), s.WebhookID,
+	)
+
+	select {
+	case got := <-ch:
+		assert.Equal(t, task.DeliveryID, got.DeliveryID)
+		assert.Equal(t, task.AttemptNum, got.AttemptNum)
+	case <-time.After(5 * time.Second):
+		t.Fatal("restart recovery did not queue the delivery again")
+	}
+}
+
+// TestEngine_StopLeavesFireAndForgetAttemptPending is the regression
+// test for a stop that turned an attempt in flight into a terminal
+// failure. Stopping the engine cancels the request; for a target with
+// no retries that was the delivery's only attempt, recorded as failed
+// with "context canceled", and nothing ever sent it again. The
+// delivery must instead stay pending, with no result and no count in
+// the attempt metrics, for restart recovery to send.
+func TestEngine_StopLeavesFireAndForgetAttemptPending(t *testing.T) {
+	t.Parallel()
+
+	s := newISetup(t)
+	reg := mIsolate(t, s)
+	lc := startEngineViaHook(t, s.Engine)
+
+	task, arrived := seedHeldDelivery(
+		t, s, 0, database.DeliveryStatusPending, 1,
+	)
+
+	s.Engine.Notify([]delivery.Task{task})
+	stopDuringAttempt(t, lc, arrived)
+
+	iAssertStatus(
+		t, s.WebhookDB, task.DeliveryID, database.DeliveryStatusPending,
+	)
+	assert.Empty(t, iResults(t, s.WebhookDB, task.DeliveryID))
+	assert.Zero(t, mCounter(t, reg, mAttempts, mTypeHTTP))
+	assert.Zero(t, mHTTPDurations(t, reg))
+
+	requireRequeued(t, s, s.Engine.ExportDeliveryCh(), task)
+}
+
+// TestEngine_StopLeavesLastRetryAttemptRetrying is the same regression
+// for a target with retries, on its last attempt: the cancelled attempt
+// used to exhaust the retries and end the delivery failed. It must stay
+// retrying with only its earlier attempt recorded, and restart recovery
+// must send that last attempt again.
+func TestEngine_StopLeavesLastRetryAttemptRetrying(t *testing.T) {
+	t.Parallel()
+
+	const maxRetries = 2
+
+	s := newISetup(t)
+	lc := startEngineViaHook(t, s.Engine)
+
+	task, arrived := seedHeldDelivery(
+		t, s, maxRetries, database.DeliveryStatusRetrying, maxRetries,
+	)
+	iSeedFailedResult(t, s.WebhookDB, task.DeliveryID)
+
+	s.Engine.ExportScheduleRetry(task, 0)
+	stopDuringAttempt(t, lc, arrived)
+
+	iAssertStatus(
+		t, s.WebhookDB, task.DeliveryID, database.DeliveryStatusRetrying,
+	)
+	assert.Len(t, iResults(t, s.WebhookDB, task.DeliveryID), 1)
+
+	requireRequeued(t, s, s.Engine.ExportRetryCh(), task)
+}
+
 // deliverToArchive gives the setup's webhook a database target,
 // runs one delivery to it through the running engine, and returns
 // the target's ID and archive file path. The archive writer holds

internal/delivery/engine_test.go

@@ -117,6 +117,18 @@ func seedDelivery(
 	return d
 }
 
+// assertStoredTime asserts that text, a timestamp as SQLite holds it,
+// is in the form GORM stores created_at in: the layout of
+// time.Time.String, with no " m=+…" monotonic clock reading after it.
+func assertStoredTime(t *testing.T, text string) {
+	t.Helper()
+
+	_, err := time.Parse(
+		"2006-01-02 15:04:05.999999999 -0700 MST", text,
+	)
+	assert.NoError(t, err, "stored as %q", text)
+}
+
 // httpDeliveryFixture holds the task and delivery needed
 // for HTTP delivery tests.
 type httpDeliveryFixture struct {

internal/delivery/inflight_test.go

@@ -462,7 +462,8 @@ func TestScheduledRetryIsNotSweptDuringBackoff(t *testing.T) {
 
 // TestRedispatchStampsTheRow pins the cadence control: a stranded
 // delivery that has just been handed out is not selected again by the
-// next tick a minute later.
+// next tick a minute later. The stamp is stored in the same form as
+// created_at.
 func TestRedispatchStampsTheRow(t *testing.T) {
 	t.Parallel()
 
@@ -493,4 +494,13 @@ func TestRedispatchStampsTheRow(t *testing.T) {
 		"a re-dispatched delivery must be stamped so the "+
 			"next tick does not select it again",
 	)
+
+	var createdAt, updatedAt string
+
+	require.NoError(t, s.WebhookDB.Raw(
+		`SELECT CAST(created_at AS TEXT), CAST(updated_at AS TEXT)
+		FROM deliveries WHERE id = ?`, d.ID,
+	).Row().Scan(&createdAt, &updatedAt))
+	assertStoredTime(t, createdAt)
+	assertStoredTime(t, updatedAt)
 }

internal/delivery/target.go

@@ -32,7 +32,8 @@ type Scheduler interface {
 // Engine.observeAttempt, alongside the DeliveryResult it records for
 // it. Deliver is also entered for attempts that never happen — an
 // open circuit breaker refuses one — so the count cannot be taken
-// from around this call.
+// from around this call. An attempt cut off by a stop is neither
+// counted nor recorded.
 type Target interface {
 	Deliver(
 		ctx context.Context,

internal/delivery/target_database_archive.go

@@ -277,7 +277,11 @@ func (w *archiveWriter) write(
 		}
 	}
 
-	row.ArchivedAt = time.Now()
+	// GORM's clock, the one that stamps created_at in the other
+	// databases, so this is stored in the same form. A bare time.Now()
+	// carries a monotonic clock reading, which the driver would store
+	// as an " m=+…" suffix.
+	row.ArchivedAt = w.db.NowFunc()
 
 	err := w.db.Create(&row).Error
 	if err != nil {

internal/delivery/target_database_test.go

@@ -150,6 +150,13 @@ func TestArchiveWriter_WritesRow(t *testing.T) {
 	assert.Equal(t, row.ContentType, got[0].ContentType)
 	assert.JSONEq(t, `{"hello":"world"}`, got[0].Body)
 	assert.False(t, got[0].ArchivedAt.IsZero())
+
+	var archivedAt string
+
+	require.NoError(t, w.DB().Raw(
+		"SELECT CAST(archived_at AS TEXT) FROM archived_events",
+	).Row().Scan(&archivedAt))
+	assertStoredTime(t, archivedAt)
 }
 
 func TestArchiveWriter_RecreatesAfterRemoval(

internal/delivery/target_headers.go

@@ -82,8 +82,8 @@ func isReservedTargetHeader(name string) bool {
 // one pair silently overwriting the other.
 //
 // An input with no pairs yields an empty map, which omitempty drops
-// from the stored config: a target configured with no headers keeps
+// from the stored config, so a target configured with no headers
-// the same config JSON it had before this field existed.
+// stores no headers key at all.
 func ParseTargetHeaders(raw string) (map[string]string, error) {
 	headers := make(map[string]string)
 

internal/delivery/target_http.go

@@ -57,7 +57,11 @@ type httpCore struct {
 // recorded and no circuit breaker is consulted. A positive
 // maxRetries gates the attempt on the circuit breaker and
 // schedules a backed-off retry on failure.
+//
+// ctx is the context attempt sends its request with. Stopping the
+// engine cancels it; see interruptedByStop.
 func (c *httpCore) deliver(
+	ctx context.Context,
 	webhookDB *gorm.DB,
 	d *database.Delivery,
 	task *Task,
@@ -66,21 +70,55 @@ func (c *httpCore) deliver(
 	attempt func() attemptResult,
 ) {
 	if maxRetries == 0 {
-		c.fireAndForget(webhookDB, d, attempt())
+		c.fireAndForget(ctx, webhookDB, d, attempt())
 
 		return
 	}
 
 	c.withRetry(
-		webhookDB, d, task, sched, maxRetries, attempt,
+		ctx, webhookDB, d, task, sched, maxRetries, attempt,
 	)
 }
 
+// interruptedByStop reports whether an attempt failed because the
+// engine is stopping, which cancels the context its request is made
+// with. Such an attempt is not recorded: no DeliveryResult, no circuit
+// breaker outcome, no status change, no count in the attempt metrics.
+// The delivery stays pending or retrying, and startup recovery sends
+// it again on the next start.
+//
+// A target's own timeout leaves that context alone, so its attempt is
+// still recorded as the failure it is.
+func (c *httpCore) interruptedByStop(
+	ctx context.Context,
+	d *database.Delivery,
+	res attemptResult,
+) bool {
+	if res.success || ctx.Err() == nil {
+		return false
+	}
+
+	c.eng.log.Warn(
+		"delivery attempt interrupted by shutdown; not recorded, "+
+			"it is sent again on the next start",
+		"delivery_id", d.ID,
+		"event_id", d.EventID,
+		"target_id", d.TargetID,
+	)
+
+	return true
+}
+
 func (c *httpCore) fireAndForget(
+	ctx context.Context,
 	webhookDB *gorm.DB,
 	d *database.Delivery,
 	res attemptResult,
 ) {
+	if c.interruptedByStop(ctx, d, res) {
+		return
+	}
+
 	c.eng.observeAttempt(d.Target.Type, res.elapsed())
 
 	err := c.eng.recordResult(
@@ -110,6 +148,7 @@ func (c *httpCore) fireAndForget(
 }
 
 func (c *httpCore) withRetry(
+	ctx context.Context,
 	webhookDB *gorm.DB,
 	d *database.Delivery,
 	task *Task,
@@ -131,6 +170,10 @@ func (c *httpCore) withRetry(
 
 	res := attempt()
 
+	if c.interruptedByStop(ctx, d, res) {
+		return
+	}
+
 	c.eng.observeAttempt(d.Target.Type, res.elapsed())
 
 	err := c.eng.recordResult(
@@ -395,7 +438,7 @@ func (t *httpTarget) Deliver(
 	}
 
 	t.deliver(
-		webhookDB, d, task, sched,
+		ctx, webhookDB, d, task, sched,
 		d.Target.MaxRetries, attempt,
 	)
 }

internal/delivery/target_redact.go

@@ -13,9 +13,9 @@ import (
 const RedactionMarker = "(redacted)"
 
 // Redactor removes one target's own credential material from
-// text that target's remote peer chose: a delivery response
+// a delivery response body, whose text the target's remote
-// body, or a delivery error stored before the delivery path
+// peer chose, and from a stored delivery error as a second
-// learned to mask the URLs it embeds.
+// line behind the delivery path's own URL masking.
 //
 // It removes byte-identical echoes of strings taken from the
 // target's stored configuration, and nothing else. Anything

internal/delivery/target_slack.go

@@ -82,7 +82,7 @@ func (t *slackTarget) Deliver(
 	}
 
 	t.deliver(
-		webhookDB, d, task, sched,
+		ctx, webhookDB, d, task, sched,
 		d.Target.MaxRetries, attempt,
 	)
 }

internal/handlers/delivery_attempts_test.go

@@ -42,9 +42,6 @@ func TestDeliveryAttempts_ReadInTheTargetTypesOwnTerms(t *testing.T) {
 		{database.TargetTypeLog, true, 0, "", "written to the log", ""},
 	}
 
-	// Named for type and outcome, so that no two cases share a name:
-	// Go adds "#01" to a repeated one, and a "#" in the temporary
-	// directory's path cuts the path SQLiteDSN gives SQLite short.
 	for _, tc := range cases {
 		t.Run(string(tc.targetType)+" "+tc.outcome, func(t *testing.T) {
 			t.Parallel()

internal/handlers/delivery_result_view.go

@@ -12,13 +12,12 @@ import (
 //
 // The bound is enforced here and in SQL, because this page's
 // memory profile must not depend on a constant in another
-// package staying where it is, and because rows predating the
+// package staying where it is, or on every stored row having
-// delivery engine's own cap or restored from an archive are
+// been written by the delivery engine under its own cap.
-// not covered by it at all.
 //
 // It happens to equal that engine cap, so a row written by the
-// current engine reaches this one exactly and is never cut
+// engine reaches this one exactly and is never cut twice.
-// twice. Nothing here may assume the two differ: see view.
+// Nothing here may assume the two differ: see view.
 const maxRenderedResponseBytes = 4096
 
 // deliveryResultColumns is the delivery attempt projection.
@@ -40,9 +39,8 @@ const deliveryResultColumns = "delivery_id, attempt_num, created_at, " +
 //
 // Both Error and ResponseBody have been through the target's
 // Redactor. The engine already masks the URL out of the
-// errors it stores, so for errors this is a second line
+// errors it stores, so for errors this is a second line; for
-// covering rows written before it did; for response bodies it
+// response bodies it is the only line, and its reach is what
-// is the only line, and its reach is what
 // delivery.Redactor documents.
 type DeliveryResultView struct {
 	AttemptNum int

internal/handlers/target_retries.go

@@ -49,13 +49,6 @@ var (
 // working retry configuration over a typo. A default answers a
 // question that was not asked; it never answers one that was asked
 // badly.
-//
-// A target stored with a count above the ceiling before this
-// validation existed keeps rendering and keeps delivering — nothing
-// clamps the row. Re-saving it from the edit form does have to bring
-// it into range, because the form submits the pre-filled value back
-// and accepting it would be the ceiling not applying to the edit
-// path. The 400 names the ceiling, so the fix is one field.
 func parseMaxRetries(raw string, fallback int) (int, error) {
 	raw = strings.TrimSpace(raw)
 	if raw == "" {

internal/session/session.go

@@ -441,10 +441,9 @@ func (s *Session) Regenerate(
 //
 // Whichever comes first ends the session.
 //
-// A session that claims to be authenticated but carries no
+// A session that claims to be authenticated but lacks the timestamp
-// timestamps predates this check; it is treated as expired so the
+// a deadline is measured from is treated as expired, so the user
-// user re-authenticates rather than being granted an unbounded
+// re-authenticates rather than being granted an unbounded session.
-// session.
 func (s *Session) expired(sess *sessions.Session) bool {
 	now := s.now()
 

internal/versionscript/version_script_test.go

@@ -156,7 +156,8 @@ func TestVersion_IsStableAcrossInvocations(t *testing.T) {
 // The build target is the only place composing linker flags. If a
 // future edit drops either half, the binary silently reports "dev"
 // again (the defect this package exists for) or fails to link on
-// Alpine.
+// Alpine. If it stops passing GO_TAGS, the image's static binary links
+// glibc's getaddrinfo and dlopen again.
 func TestMakefile_BuildComposesVersionAndExtraFlags(t *testing.T) {
 	t.Parallel()
 
@@ -164,6 +165,7 @@ func TestMakefile_BuildComposesVersionAndExtraFlags(t *testing.T) {
 
 	require.Contains(t, makefile, "-X main.version=$(VERSION)")
 	require.Contains(t, makefile, "$(GO_LDFLAGS)")
+	require.Contains(t, makefile, "-tags '$(GO_TAGS)'")
 	require.Contains(t, makefile, "VERSION ?= $(shell script/version)")
 }
 
@@ -233,7 +235,9 @@ func TestDockerfile_BuildsThroughTheMakeTarget(t *testing.T) {
 		"a raw go build bypasses the Makefile's -X flag")
 	require.Contains(t, dockerfile, "ARG VERSION")
 	require.Contains(t, dockerfile,
-		`make build VERSION="$VERSION" GO_LDFLAGS='-extldflags "-static"'`)
+		`make build VERSION="$VERSION"`+
+			` GO_TAGS=netgo,osusergo,sqlite_omit_load_extension`+
+			` GO_LDFLAGS='-extldflags "-static"'`)
 }
 
 func read(t *testing.T, path string) string {