Refactor Kafka publishing without DB outbox

server/kafka_dead_letters.go

@@ -6,10 +6,57 @@ import (
 	"strings"
 	"time"
 
+	"github.com/segmentio/kafka-go"
+	"github.com/tinode/chat/server/logs"
 	"github.com/tinode/chat/server/store"
 	"github.com/tinode/chat/server/store/types"
 )
 
+func startKafkaDeadLetterConsumer() {
+	startKafkaConsumer("dead_letter", handleKafkaDeadLetter)
+}
+
+func handleKafkaDeadLetter(ctx context.Context, envelope kafkaEnvelope, _ kafka.Message) error {
+	var dead types.KafkaDeadLetter
+	if err := json.Unmarshal(envelope.Payload, &dead); err != nil {
+		return err
+	}
+	if dead.DeadID == "" {
+		dead.DeadID = envelope.EventID
+	}
+	tenantID, err := tenantIDFromDeadLetter(envelope, &dead)
+	if err != nil {
+		return err
+	}
+	now := time.Now().UTC().Round(time.Millisecond)
+	if err = store.HTTPInfrastructure.MarkKafkaConsumeDead(tenantID, &dead, now); err != nil {
+		return err
+	}
+	if auditErr := enqueueKafkaAuditEvent(ctx, tenantID, "system", types.ZeroUid, "kafka.dead_letter.created", "kafka_event", dead.EventID, "dead", dead.LastReason, map[string]any{
+		"dead_id":        dead.DeadID,
+		"event_type":     dead.EventType,
+		"biz_type":       dead.BizType,
+		"biz_id":         dead.BizID,
+		"consumer_group": dead.ConsumerGroup,
+	}); auditErr != nil {
+		logs.Warn.Printf("kafka dead letter audit enqueue failed: event=%s dead=%s err=%v", dead.EventID, dead.DeadID, auditErr)
+	}
+	return nil
+}
+
+func tenantIDFromDeadLetter(envelope kafkaEnvelope, dead *types.KafkaDeadLetter) (types.TenantID, error) {
+	if !envelope.TenantID.IsZero() {
+		return envelope.TenantID, nil
+	}
+	if dead != nil && len(dead.Envelope) > 0 {
+		var original kafkaEnvelope
+		if err := json.Unmarshal(dead.Envelope, &original); err == nil && !original.TenantID.IsZero() {
+			return original.TenantID, nil
+		}
+	}
+	return kafkaTenantID(envelope.TenantCode)
+}
+
 func replayKafkaDeadLetter(ctx context.Context, tenantID types.TenantID, deadID string, actor types.Uid, note string) (*types.KafkaDeadLetter, error) {
 	now := time.Now().UTC().Round(time.Millisecond)
 	dead, err := store.HTTPInfrastructure.MarkKafkaDeadLetterReplay(tenantID, deadID, actor.UserId(), note, now)