Store events and create deliveries in the delivery engine (closes #544)

The receiver, resubmit and replay handlers now read and check the
request and make one call. Engine.StoreEvent stores an event with a
pending delivery for each active target and the totals in one
transaction, then queues them; Engine.CreateReplay does the same for
one replay delivery. The handlers take *delivery.Engine, so the
Notifier interface and its bridge are gone, and the engine's notify is
no longer exported. Archives and CircuitBreakers stay because the
handler tests fake them. The tests that read a queued task moved to
the engine's tests; the handler tests use an engine that is never
started.

Model: opus-5-5

internal/handlers/delivery_replay.go

@@ -5,9 +5,7 @@ import (
 
 	"github.com/go-chi/chi"
 	"gorm.io/gorm"
-	"gorm.io/gorm/clause"
 	"sneak.berlin/go/webhooker/internal/database"
-	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
 // The outcomes of a replay POST, as the notice codes its redirect
@@ -46,12 +44,12 @@ const (
 // HandleDeliveryReplay re-sends a finished delivery's event to its
 // target.
 //
-// A replay never touches the delivery it repeats. It creates a NEW
-// pending delivery row for the same event and target and hands it to
-// the delivery engine through the same Notifier the receiver uses, so
-// the original's status, attempts and timestamps stand as the record
-// of what actually happened, and the replay is retried, SSRF-guarded
-// and circuit-broken exactly as a first attempt is.
+// A replay never touches the delivery it repeats. The delivery engine
+// creates a NEW pending delivery row for the same event and target and
+// queues it as it queues the receiver's, so the original's status,
+// attempts and timestamps stand as the record of what actually
+// happened, and the replay is retried, SSRF-guarded and circuit-broken
+// exactly as a first attempt is.
 //
 // What is re-sent is the stored EVENT body, never the response the
 // original delivery received.
@@ -145,7 +143,8 @@ func (h *Handlers) loadReplaySource(
 	return &original, true
 }
 
-// queueReplay writes the new delivery and hands it to the engine.
+// queueReplay has the delivery engine create and queue the new
+// delivery, unless an earlier replay is still in flight.
 func (h *Handlers) queueReplay(
 	w http.ResponseWriter,
 	r *http.Request,
@@ -171,18 +170,8 @@ func (h *Handlers) queueReplay(
 		return
 	}
 
-	var event database.Event
-
-	err = webhookDB.
-		First(&event, "id = ?", original.EventID).Error
-	if err != nil {
-		h.serverError(w, r, "failed to load event for replay", err)
-
-		return
-	}
-
-	task, err := createReplayDelivery(
-		webhookDB, webhook.ID, &event, target,
+	deliveryID, err := h.engine.CreateReplay(
+		webhook.ID, original.EventID, target,
 	)
 	if err != nil {
 		h.serverError(
@@ -193,15 +182,14 @@ func (h *Handlers) queueReplay(
 	}
 
 	h.mtr.DeliveryReplayed(target.Type)
-	h.notifier.Notify([]delivery.Task{task})
 
 	h.log.Info(
 		"delivery replay queued",
 		"webhook_id", webhook.ID,
-		"event_id", event.ID,
+		"event_id", original.EventID,
 		"target_id", target.ID,
 		"replayed_delivery_id", original.ID,
-		"delivery_id", task.DeliveryID,
+		"delivery_id", deliveryID,
 	)
 
 	redirectToEventLog(w, r, webhook, replayQueued)
@@ -263,77 +251,6 @@ func countInFlightDeliveries(
 	return count, err
 }
 
-// createReplayDelivery writes the new pending delivery row, adds it to
-// its target's totals in the same transaction, and returns the task
-// that carries it to the delivery engine.
-//
-// The row is written with associations omitted, and neither Event nor
-// Target is populated on it: GORM's SaveBeforeAssociations would
-// otherwise upsert the whole target row — plaintext config, which for a
-// Slack target is the credential — into the per-webhook event database.
-// See https://git.eeqj.de/sneak/webhooker/issues/206.
-func createReplayDelivery(
-	webhookDB *gorm.DB,
-	webhookID string,
-	event *database.Event,
-	target *database.Target,
-) (delivery.Task, error) {
-	dlv := &database.Delivery{
-		EventID:  event.ID,
-		TargetID: target.ID,
-		Status:   database.DeliveryStatusPending,
-		Replay:   true,
-	}
-
-	err := webhookDB.Transaction(func(tx *gorm.DB) error {
-		err := tx.Omit(clause.Associations).Create(dlv).Error
-		if err != nil {
-			return err
-		}
-
-		return database.AddTargetTotals(tx, database.TargetTotals{
-			TargetID: dlv.TargetID, Deliveries: 1,
-		})
-	})
-	if err != nil {
-		return delivery.Task{}, err
-	}
-
-	return delivery.Task{
-		DeliveryID:      dlv.ID,
-		EventID:         event.ID,
-		WebhookID:       webhookID,
-		EntrypointID:    event.EntrypointID,
-		TargetID:        target.ID,
-		TargetName:      target.Name,
-		TargetType:      target.Type,
-		TargetURL:       target.URL,
-		TargetHeaders:   target.Headers,
-		TimeoutSeconds:  target.TimeoutSeconds,
-		ForwardQuery:    target.ForwardQuery,
-		ArchiveExpiry:   target.ArchiveExpiry,
-		ArchiveRotation: target.ArchiveRotation,
-		MaxAttempts:     target.MaxAttempts,
-		Method:          event.Method,
-		RawQuery:        event.RawQuery,
-		Headers:         event.Headers,
-		ContentType:     event.ContentType,
-		Body:            replayBody(event.Body),
-		AttemptNum:      1,
-	}, nil
-}
-
-// replayBody returns the stored event body for a replay task to carry
-// inline, or nil when it is large enough that the engine should fetch
-// it from the per-webhook database instead.
-func replayBody(body string) *string {
-	if len(body) >= delivery.MaxInlineBodySize {
-		return nil
-	}
-
-	return &body
-}
-
 // redirectToEventLog redirects a replay or resubmit back to the event
 // log it was triggered from, carrying the outcome as its notice. A
 // Replay form carries the list it was pressed in as show, so a replay