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Notification service

Centralized notification delivery: email (AWS SES), templates, delivery tracking, unsubscribe handling, and processing with retries. The API is fire-and-forget (acceptance is not final delivery). See services/notification-service/README.md for module entry points.

SES SNS webhook (spec)

Endpoint: POST /notifications/webhooks/ses — raw SNS JSON body. Return 200 OK for all valid requests (including subscription confirmations and unknown message IDs). Security: @PermitAll; authenticity via SNS signature verification only.

1. SNS message handling

  • Type = SubscriptionConfirmation — HTTP GET SubscribeURL to confirm. No DB changes. Return 200.
  • Type = UnsubscribeConfirmation — Optional GET UnsubscribeURL or ignore. Return 200.
  • Type = Notification — Verify signature (cert from SigningCertURL, canonical string per AWS docs). Reject 4xx if invalid. Parse Message as JSON (SES event). Extract mail.messageId, notificationType (Bounce | Complaint | Delivery). If not Bounce/Complaint/Delivery, return 200 and skip.

2. Linking to our notification

  • Add NotificationRepository findByProviderMessageId(String) (and index on notifications.provider_message_id if needed). Look up by mail.messageId. If not found, return 200 and skip (idempotent).

3. Persisting outcome

  • Map: Delivery → DeliveryEvent.DELIVERED, NotificationStatus.DELIVERED; Bounce → DeliveryEvent.BOUNCED, NotificationStatus.BOUNCED; Complaint → DeliveryEvent.COMPLAINT, NotificationStatus.COMPLAINT. Insert DeliveryStatusRecord; update NotificationRecord.status. Idempotent where possible (e.g. same messageId + event type).

4. Parsing & DTOs

  • Outer SNS envelope: Type, Message, MessageId, SigningCertURL, SubscribeURL, etc. Inner SES event: notificationType, mail.messageId, bounce / complaint / delivery. Parse Message as JSON; handle missing fields safely.

5. Signature verification

  • Fetch cert from SigningCertURL (HTTPS only). Build canonical string per AWS SNS docs; verify signature. 4xx on failure.

6. Config / AWS

  • SES Configuration Set → SNS Topic → HTTPS subscription to this endpoint. Optional config to disable processing (e.g. LocalStack); endpoint still returns 200.

7. LocalStack

  • No SNS webhooks in LocalStack. Unknown messageId or disabled config → 200, no DB update.

8. Testing

  • Unit: signature valid/invalid, parse Bounce/Complaint/Delivery, map to domain, "notification not found". Integration: POST sample SNS payloads (SubscriptionConfirmation + Notification), assert 200 and DB updates where applicable

LocalStack (minimal)

  • Start LocalStack; the notification service registers the configured from-address (default noreply@<domainRoot>) in dev, or run awslocal ses verify-email-identity for a custom notification.ses.from-email. Set aws.ses.endpoint to LocalStack. Inspect sent emails: curl http://localhost:4566/_aws/ses. SNS webhooks not supported; use polling or no-op for webhook endpoint.

References

Updated 10 days ago