Implement the database archiving target (closes #43)

internal/delivery/export_test.go

@@ -273,3 +273,64 @@ func NewTestCircuitBreaker(
 		cooldown:  cooldown,
 	}
 }
+
+// ExportArchivedEvent aliases the archive row type so black-box
+// tests can construct and read archive rows.
+type ExportArchivedEvent = archivedEvent
+
+// ExportArchiveWriter wraps an archiveWriter so black-box tests
+// can exercise the per-webhook archive file mechanics.
+type ExportArchiveWriter struct {
+	w *archiveWriter
+}
+
+// NewExportArchiveWriter builds an archive writer for tests,
+// optionally overriding the reopen debounce (a non-positive
+// debounce keeps the production default).
+func NewExportArchiveWriter(
+	path string, log *slog.Logger, debounce time.Duration,
+) *ExportArchiveWriter {
+	w := newArchiveWriter(path, log)
+	if debounce > 0 {
+		w.debounce = debounce
+	}
+
+	return &ExportArchiveWriter{w: w}
+}
+
+// Write archives a row through the writer.
+func (e *ExportArchiveWriter) Write(
+	row ExportArchivedEvent, expiry time.Duration,
+) error {
+	return e.w.write(row, expiry)
+}
+
+// Open opens the archive file, pruning when expiry is positive.
+func (e *ExportArchiveWriter) Open(expiry time.Duration) error {
+	return e.w.open(expiry)
+}
+
+// Reopen closes and reopens the archive file.
+func (e *ExportArchiveWriter) Reopen(
+	expiry time.Duration,
+) error {
+	return e.w.reopen(expiry)
+}
+
+// Reopens reports how many times the file has been opened.
+func (e *ExportArchiveWriter) Reopens() int {
+	return e.w.reopens
+}
+
+// DB returns the writer's current open handle for row
+// inspection in tests.
+func (e *ExportArchiveWriter) DB() *gorm.DB {
+	return e.w.db
+}
+
+// ExportParseArchiveExpiry exposes parseArchiveExpiry.
+func ExportParseArchiveExpiry(
+	configJSON string,
+) (time.Duration, error) {
+	return parseArchiveExpiry(configJSON)
+}

internal/delivery/target_database.go

@@ -2,21 +2,35 @@ package delivery
 
 import (
 	"context"
+	"fmt"
+	"path/filepath"
+	"sync"
 
 	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/database"
 )
 
-// databaseTarget is a fire-and-forget target: the event is
-// already persisted in the per-webhook database by the time
-// delivery runs, so the target records a single successful
-// attempt. (Durable archiving to a separate store is tracked
-// as its own work.)
+// databaseTarget is a fire-and-forget target that archives the
+// full inbound event into a per-webhook archive SQLite file,
+// separate from the per-webhook event database. The event is
+// already persisted in the per-webhook event DB by the time
+// delivery runs; the database target additionally writes a
+// durable long-term copy into archive-{webhookID}.db and then
+// records a single successful attempt. See archiveWriter for
+// the close/reopen, auto-recreate, and expiry semantics.
 type databaseTarget struct {
 	eng *Engine
+
+	mu      sync.Mutex
+	writers map[string]*archiveWriter
 }
 
-// Deliver implements Target.
+// Deliver implements Target. It archives the event, then
+// records one successful attempt and marks the delivery
+// delivered. Archiving errors are logged but do not fail the
+// delivery: the event is already durably stored in the
+// per-webhook event database, so the target stays
+// fire-and-forget.
 func (t *databaseTarget) Deliver(
 	_ context.Context,
 	webhookDB *gorm.DB,
@@ -24,6 +38,16 @@ func (t *databaseTarget) Deliver(
 	_ *Task,
 	_ Scheduler,
 ) {
+	err := t.archive(d)
+	if err != nil {
+		t.eng.log.Error(
+			"failed to archive event to database target",
+			"delivery_id", d.ID,
+			"event_id", d.EventID,
+			"error", err,
+		)
+	}
+
 	t.eng.recordResult(
 		webhookDB, d, 1, true, 0, "", "", 0,
 	)
@@ -32,3 +56,68 @@ func (t *databaseTarget) Deliver(
 		webhookDB, d, database.DeliveryStatusDelivered,
 	)
 }
+
+// archive writes the full event as a row into the webhook's
+// archive database, honouring the optional per-target expiry
+// parsed from the target config JSON.
+func (t *databaseTarget) archive(d *database.Delivery) error {
+	webhookID := d.Event.WebhookID
+	if webhookID == "" {
+		return errArchiveMissingWebhookID
+	}
+
+	expiry, err := parseArchiveExpiry(d.Target.Config)
+	if err != nil {
+		return err
+	}
+
+	w, err := t.writerFor(webhookID)
+	if err != nil {
+		return err
+	}
+
+	row := archivedEvent{
+		EventID:      d.Event.ID,
+		WebhookID:    webhookID,
+		EntrypointID: d.Event.EntrypointID,
+		Method:       d.Event.Method,
+		Headers:      d.Event.Headers,
+		Body:         d.Event.Body,
+		ContentType:  d.Event.ContentType,
+	}
+
+	return w.write(row, expiry)
+}
+
+// writerFor returns the archiveWriter for a webhook, creating
+// and caching it on first use. Each webhook has one writer so
+// its close/reopen debounce state is shared across concurrent
+// deliveries. The archive file lives beside the per-webhook
+// event database in the data directory.
+func (t *databaseTarget) writerFor(
+	webhookID string,
+) (*archiveWriter, error) {
+	if t.eng.dbManager == nil {
+		return nil, errArchiveNoDataDir
+	}
+
+	dir := filepath.Dir(t.eng.dbManager.DBPath(webhookID))
+	path := filepath.Join(
+		dir, fmt.Sprintf("archive-%s.db", webhookID),
+	)
+
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	if t.writers == nil {
+		t.writers = make(map[string]*archiveWriter)
+	}
+
+	w, ok := t.writers[webhookID]
+	if !ok {
+		w = newArchiveWriter(path, t.eng.log)
+		t.writers[webhookID] = w
+	}
+
+	return w, nil
+}

internal/delivery/target_database_archive.go

@@ -0,0 +1,271 @@
+package delivery
+
+import (
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"log/slog"
+	"os"
+	"sync"
+	"time"
+
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+)
+
+// archiveExpiryNever is the expiry sentinel (and default) that
+// disables pruning so archived rows are kept forever.
+const archiveExpiryNever = "never"
+
+// archiveReopenDebounce bounds how often an archive file is
+// closed and reopened. After each write the handle is closed
+// and reopened so an operator can move the file away for
+// offline archiving, but never more than once per this window.
+const archiveReopenDebounce = time.Second
+
+var (
+	// errArchiveMissingWebhookID is returned when an event to
+	// archive has no webhook id to key its archive file on.
+	errArchiveMissingWebhookID = errors.New(
+		"cannot archive event without a webhook id",
+	)
+
+	// errArchiveNoDataDir is returned when the database target
+	// has no webhook database manager and so cannot locate the
+	// data directory for archive files.
+	errArchiveNoDataDir = errors.New(
+		"database target has no data directory",
+	)
+)
+
+// databaseTargetConfig is the optional per-target JSON config
+// for a database (archive) target.
+type databaseTargetConfig struct {
+	// Expiry is a Go duration (e.g. "720h") after which
+	// archived rows are pruned, or "never" (the default) to
+	// keep them forever.
+	Expiry string `json:"expiry"`
+}
+
+// archivedEvent is one fully captured webhook event stored in a
+// per-webhook archive database for long-term retention. It is a
+// self-contained copy — independent of the per-webhook event
+// database, which may prune events under its own retention.
+type archivedEvent struct {
+	ID           uint   `gorm:"primaryKey;autoIncrement"`
+	EventID      string `gorm:"index"`
+	WebhookID    string
+	EntrypointID string
+	Method       string
+	Headers      string
+	Body         string
+	ContentType  string
+
+	// ArchivedAt is when the row was archived and is the age
+	// basis for expiry pruning.
+	ArchivedAt time.Time `gorm:"index"`
+}
+
+// parseArchiveExpiry reads the optional expiry from a database
+// target's config JSON. An empty config, an empty expiry, or
+// the literal "never" all mean keep forever, returned as a zero
+// duration. Any other value is parsed as a Go duration.
+func parseArchiveExpiry(
+	configJSON string,
+) (time.Duration, error) {
+	if configJSON == "" {
+		return 0, nil
+	}
+
+	var cfg databaseTargetConfig
+
+	err := json.Unmarshal([]byte(configJSON), &cfg)
+	if err != nil {
+		return 0, fmt.Errorf(
+			"parsing database target config: %w", err,
+		)
+	}
+
+	if cfg.Expiry == "" || cfg.Expiry == archiveExpiryNever {
+		return 0, nil
+	}
+
+	dur, err := time.ParseDuration(cfg.Expiry)
+	if err != nil {
+		return 0, fmt.Errorf(
+			"parsing archive expiry %q: %w", cfg.Expiry, err,
+		)
+	}
+
+	if dur <= 0 {
+		return 0, nil
+	}
+
+	return dur, nil
+}
+
+// archiveWriter owns one per-webhook archive SQLite file. It
+// serialises writes, and after each write closes and reopens
+// the file (debounced to at most once per debounce window) so
+// an operator can move the file away for offline archiving. The
+// next write recreates a moved or removed file, because the
+// file is opened create-if-missing and its schema is migrated
+// on every open.
+type archiveWriter struct {
+	mu         sync.Mutex
+	path       string
+	log        *slog.Logger
+	debounce   time.Duration
+	db         *gorm.DB
+	lastReopen time.Time
+	reopens    int
+}
+
+// newArchiveWriter builds an archiveWriter for a file path with
+// the default reopen debounce.
+func newArchiveWriter(
+	path string, log *slog.Logger,
+) *archiveWriter {
+	return &archiveWriter{
+		path:     path,
+		log:      log,
+		debounce: archiveReopenDebounce,
+	}
+}
+
+// write appends the event as a row, then applies the debounced
+// close/reopen. It recreates the archive file if it was moved
+// or removed since the last open. A positive expiry prunes rows
+// older than it on each (re)open.
+func (w *archiveWriter) write(
+	row archivedEvent, expiry time.Duration,
+) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	if w.db == nil || !fileExists(w.path) {
+		err := w.reopen(expiry)
+		if err != nil {
+			return err
+		}
+	}
+
+	row.ArchivedAt = time.Now()
+
+	err := w.db.Create(&row).Error
+	if err != nil {
+		return fmt.Errorf(
+			"archiving event to %s: %w", w.path, err,
+		)
+	}
+
+	if time.Since(w.lastReopen) >= w.debounce {
+		return w.reopen(expiry)
+	}
+
+	return nil
+}
+
+// open opens (creating if missing) the archive file, migrates
+// its schema, records the reopen time, and prunes expired rows
+// when expiry is positive.
+func (w *archiveWriter) open(expiry time.Duration) error {
+	dbURL := fmt.Sprintf("file:%s?mode=rwc", w.path)
+
+	sqlDB, err := sql.Open("sqlite", dbURL)
+	if err != nil {
+		return fmt.Errorf(
+			"opening archive database %s: %w", w.path, err,
+		)
+	}
+
+	gdb, err := gorm.Open(
+		sqlite.Dialector{Conn: sqlDB}, &gorm.Config{},
+	)
+	if err != nil {
+		_ = sqlDB.Close()
+
+		return fmt.Errorf(
+			"connecting to archive database %s: %w",
+			w.path, err,
+		)
+	}
+
+	err = gdb.AutoMigrate(&archivedEvent{})
+	if err != nil {
+		_ = sqlDB.Close()
+
+		return fmt.Errorf(
+			"migrating archive database %s: %w", w.path, err,
+		)
+	}
+
+	w.db = gdb
+	w.lastReopen = time.Now()
+	w.reopens++
+
+	if expiry > 0 {
+		w.prune(expiry)
+	}
+
+	return nil
+}
+
+// reopen closes any open handle and opens the file afresh. The
+// fresh open recreates the file if it was moved away.
+func (w *archiveWriter) reopen(expiry time.Duration) error {
+	w.close()
+
+	return w.open(expiry)
+}
+
+// close closes the underlying handle, if any.
+func (w *archiveWriter) close() {
+	if w.db == nil {
+		return
+	}
+
+	sqlDB, err := w.db.DB()
+	if err == nil {
+		_ = sqlDB.Close()
+	}
+
+	w.db = nil
+}
+
+// prune deletes archived rows older than expiry, measured from
+// each row's archived time. It runs on every (re)open, and
+// because the file is reopened after writes this keeps the
+// archive swept without a separate background sweeper. Failures
+// are logged, not fatal: a prune error must not stop archiving.
+func (w *archiveWriter) prune(expiry time.Duration) {
+	cutoff := time.Now().Add(-expiry)
+
+	res := w.db.Where("archived_at < ?", cutoff).
+		Delete(&archivedEvent{})
+	if res.Error != nil {
+		w.log.Error(
+			"failed to prune expired archive rows",
+			"path", w.path,
+			"error", res.Error,
+		)
+
+		return
+	}
+
+	if res.RowsAffected > 0 {
+		w.log.Info(
+			"pruned expired archive rows",
+			"path", w.path,
+			"rows_deleted", res.RowsAffected,
+		)
+	}
+}
+
+// fileExists reports whether a path currently exists.
+func fileExists(path string) bool {
+	_, err := os.Stat(path)
+
+	return err == nil
+}

internal/delivery/target_database_test.go

@@ -0,0 +1,292 @@
+package delivery_test
+
+import (
+	"database/sql"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+	_ "modernc.org/sqlite" // Pure Go SQLite driver.
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+)
+
+func archiveTestLogger() *slog.Logger {
+	return slog.New(slog.NewTextHandler(
+		os.Stderr,
+		&slog.HandlerOptions{Level: slog.LevelDebug},
+	))
+}
+
+// openArchiveDBForRead opens an archive file read-only so a
+// test can inspect the rows the writer persisted.
+func openArchiveDBForRead(
+	t *testing.T, path string,
+) *gorm.DB {
+	t.Helper()
+
+	sqlDB, err := sql.Open(
+		"sqlite",
+		fmt.Sprintf("file:%s?mode=ro", path),
+	)
+	require.NoError(t, err)
+
+	t.Cleanup(func() { _ = sqlDB.Close() })
+
+	gdb, err := gorm.Open(
+		sqlite.Dialector{Conn: sqlDB}, &gorm.Config{},
+	)
+	require.NoError(t, err)
+
+	return gdb
+}
+
+// removeArchiveFiles simulates an operator moving the archive
+// away by deleting the SQLite file and its sidecar files.
+func removeArchiveFiles(t *testing.T, path string) {
+	t.Helper()
+
+	for _, suffix := range []string{
+		"", "-wal", "-shm", "-journal",
+	} {
+		err := os.Remove(path + suffix)
+		if err != nil && !os.IsNotExist(err) {
+			t.Fatalf("removing %s%s: %v", path, suffix, err)
+		}
+	}
+}
+
+// TestDeliverDatabase_ArchivesEvent verifies that delivering to
+// a database target marks the delivery delivered and archives
+// the full event into a separate per-webhook archive file.
+func TestDeliverDatabase_ArchivesEvent(t *testing.T) {
+	t.Parallel()
+
+	dataDir := t.TempDir()
+	dbMgr := database.NewTestWebhookDBManager(dataDir)
+
+	e := delivery.NewTestEngineWithDB(
+		nil, dbMgr,
+		archiveTestLogger(),
+		&http.Client{Timeout: 5 * time.Second},
+		1,
+	)
+
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"archived":true}`)
+
+	dlv := seedDelivery(
+		t, webhookDB, event.ID, uuid.New().String(),
+		database.DeliveryStatusPending,
+	)
+
+	d := &database.Delivery{
+		EventID:  event.ID,
+		TargetID: dlv.TargetID,
+		Status:   database.DeliveryStatusPending,
+		Event:    event,
+		Target: database.Target{
+			Name: "test-db",
+			Type: database.TargetTypeDatabase,
+		},
+	}
+	d.ID = dlv.ID
+
+	e.ExportDeliverDatabase(webhookDB, d)
+
+	var updated database.Delivery
+
+	require.NoError(t, webhookDB.First(
+		&updated, "id = ?", dlv.ID,
+	).Error)
+	assert.Equal(t,
+		database.DeliveryStatusDelivered, updated.Status,
+		"database target should mark the delivery delivered",
+	)
+
+	archivePath := filepath.Join(
+		dataDir,
+		fmt.Sprintf("archive-%s.db", event.WebhookID),
+	)
+	assert.FileExists(t, archivePath)
+
+	rdb := openArchiveDBForRead(t, archivePath)
+
+	var rows []delivery.ExportArchivedEvent
+
+	require.NoError(t, rdb.Find(&rows).Error)
+	require.Len(t, rows, 1)
+	assert.Equal(t, event.ID, rows[0].EventID)
+	assert.Equal(t, event.WebhookID, rows[0].WebhookID)
+	assert.Equal(t, event.Method, rows[0].Method)
+	assert.JSONEq(t, `{"archived":true}`, rows[0].Body)
+}
+
+func TestArchiveWriter_WritesRow(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-wh.db")
+	w := delivery.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	row := delivery.ExportArchivedEvent{
+		EventID:      "ev-1",
+		WebhookID:    "wh-1",
+		EntrypointID: "ep-1",
+		Method:       "POST",
+		Headers:      `{"X":"Y"}`,
+		Body:         `{"hello":"world"}`,
+		ContentType:  "application/json",
+	}
+
+	require.NoError(t, w.Write(row, 0))
+	assert.FileExists(t, path)
+
+	var got []delivery.ExportArchivedEvent
+
+	require.NoError(t, w.DB().Find(&got).Error)
+	require.Len(t, got, 1)
+	assert.Equal(t, "ev-1", got[0].EventID)
+	assert.Equal(t, "wh-1", got[0].WebhookID)
+	assert.Equal(t, "ep-1", got[0].EntrypointID)
+	assert.Equal(t, row.Method, got[0].Method)
+	assert.Equal(t, row.ContentType, got[0].ContentType)
+	assert.JSONEq(t, `{"hello":"world"}`, got[0].Body)
+	assert.False(t, got[0].ArchivedAt.IsZero())
+}
+
+func TestArchiveWriter_RecreatesAfterRemoval(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-wh.db")
+	w := delivery.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.Write(
+		delivery.ExportArchivedEvent{EventID: "a"}, 0,
+	))
+	assert.FileExists(t, path)
+
+	// The operator moves the archive away while the handle is
+	// still open.
+	removeArchiveFiles(t, path)
+	require.NoFileExists(t, path)
+
+	// The next write recreates the file with a fresh schema and
+	// only the new row.
+	require.NoError(t, w.Write(
+		delivery.ExportArchivedEvent{EventID: "b"}, 0,
+	))
+	assert.FileExists(t, path)
+
+	var got []delivery.ExportArchivedEvent
+
+	require.NoError(t, w.DB().Find(&got).Error)
+	require.Len(t, got, 1)
+	assert.Equal(t, "b", got[0].EventID)
+}
+
+func TestArchiveWriter_ReopenDebounce(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-wh.db")
+	w := delivery.NewExportArchiveWriter(
+		path, archiveTestLogger(), 20*time.Millisecond,
+	)
+
+	require.NoError(t, w.Write(
+		delivery.ExportArchivedEvent{EventID: "a"}, 0,
+	))
+	require.NoError(t, w.Write(
+		delivery.ExportArchivedEvent{EventID: "b"}, 0,
+	))
+
+	// Two writes inside the debounce window trigger only the
+	// initial open — no extra close/reopen.
+	assert.Equal(t, 1, w.Reopens())
+
+	time.Sleep(30 * time.Millisecond)
+
+	require.NoError(t, w.Write(
+		delivery.ExportArchivedEvent{EventID: "c"}, 0,
+	))
+
+	// A write after the window elapses closes and reopens once.
+	assert.Equal(t, 2, w.Reopens())
+}
+
+func TestArchiveWriter_ExpiryPrune(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-wh.db")
+	w := delivery.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.Open(0))
+
+	old := delivery.ExportArchivedEvent{
+		EventID:    "old",
+		ArchivedAt: time.Now().Add(-2 * time.Hour),
+	}
+	fresh := delivery.ExportArchivedEvent{
+		EventID:    "fresh",
+		ArchivedAt: time.Now(),
+	}
+
+	require.NoError(t, w.DB().Create(&old).Error)
+	require.NoError(t, w.DB().Create(&fresh).Error)
+
+	// Reopening with a one-hour expiry prunes the old row.
+	require.NoError(t, w.Reopen(time.Hour))
+
+	var got []delivery.ExportArchivedEvent
+
+	require.NoError(t, w.DB().Find(&got).Error)
+	require.Len(t, got, 1)
+	assert.Equal(t, "fresh", got[0].EventID)
+}
+
+func TestParseArchiveExpiry(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name string
+		in   string
+		want time.Duration
+	}{
+		{"empty config", "", 0},
+		{"explicit never", `{"expiry":"never"}`, 0},
+		{"empty expiry", `{"expiry":""}`, 0},
+		{"duration", `{"expiry":"1h"}`, time.Hour},
+		{"zero duration", `{"expiry":"0s"}`, 0},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			got, err := delivery.ExportParseArchiveExpiry(tc.in)
+			require.NoError(t, err)
+			assert.Equal(t, tc.want, got)
+		})
+	}
+
+	_, err := delivery.ExportParseArchiveExpiry(
+		`{"expiry":"nonsense"}`,
+	)
+	require.Error(t, err)
+}