PicPeak POSTs lifecycle notifications to admin-configured URLs. Each
delivery is signed HMAC-SHA256 in the X-PicPeak-Signature header.
Verified end-to-end: 1/1 Playwright spec, 8/8 backend integration
tests, full UI click-through via Chrome DevTools.
Schema (migration 082)
- webhooks: id, name, url, secret (plaintext — required to compute HMAC
for every outbound POST), secret_preview, events[], active, filter,
template, created_by, timestamps, last_success_at/last_failure_at.
- webhook_deliveries: webhook_id (FK CASCADE), event_type, payload,
attempt_count, status (pending|success|failed), response_status,
response_body (truncated to 1KB), latency_ms, next_retry_at,
last_error, created_at, completed_at. Composite index
(status, next_retry_at) serves the worker's hot-path query.
Service + worker
- webhookService.fire(eventType, data) — non-throwing entry point used
by lifecycle hooks. Looks up active webhooks subscribed to the event
and applies their per-webhook filter (dot-path equality predicate)
before enqueueing one webhook_deliveries row per match. Filter and
template logic ship in this commit; admin surfaces in the follow-up.
- webhookDeliveryWorker — setInterval(5s) poller; fetches up to 5
pending rows; per delivery: re-validates URL via networkValidation
(DNS-rebinding mitigation, opt-out via WEBHOOK_ALLOW_PRIVATE_URLS),
signs body with HMAC-SHA256, POSTs with 10s timeout, records outcome.
Backoff schedule: 1m → 5m → 30m → 2h → 12h, max 5 attempts. Response
body truncated to 1KB before storage. If a webhook has a template,
the rendered string replaces the JSON envelope as the request body
(signature is computed over the bytes actually sent).
Lifecycle wiring
- adminEvents.js POST /events → event.created (+ event.published when
not draft); POST /:id/publish → event.published.
- routes/events.js (legacy public POST) → event.created + event.published.
- routes/v1/events.js (#322 API) → event.created + event.published on
create, photo.uploaded on photo POST.
- archiveService.archiveEvent() → event.archived. Per-photo
photo.deleted intentionally NOT fired during cascade — receivers
infer from event.archived to avoid flooding (issue spec).
- expirationChecker.handleExpiredEvent() → event.expired BEFORE the
cascading archive (so receivers see expired→archived in order).
- adminPhotos.js — photo.uploaded on each batch row, photo.deleted on
single + bulk delete.
- photoProcessor.js — photo.uploaded for guest uploads + auto-import
(covers all entry paths).
- fileWatcher.js — photo.uploaded on add, photo.deleted on unlink
(local mode only).
Admin endpoints (mirrors adminApiTokens.js pattern)
- /api/admin/webhooks: GET list, POST create (returns plaintext secret
exactly once), GET :id, PUT :id, DELETE :id, POST :id/test (synthetic
fire), GET :id/deliveries (paginated, filter by status), GET
:id/deliveries/:deliveryId, POST :id/deliveries/:deliveryId/replay.
Frontend
- Settings → Webhooks tab (mirrors API Tokens layout): name + URL +
event checkboxes + "Advanced" expander for filter (JSON) and template.
Plaintext secret shown once on creation with a Copy button. Active/
Disabled toggle button per row.
- /admin/webhooks/:id/deliveries — operational debug surface. Table
with timestamp/event/status/attempts/HTTP/latency. Status filter chips
(all/pending/success/failed). Row click → slide-over with payload +
signature + response body. Replay button on failed rows. Send-test-event
dialog. Auto-refresh every 10s.
Dev infrastructure
- dev/webhook-receiver/ — tiny node:alpine HTTP server (~100 LOC) that
records every POST to an in-memory ring buffer. Exposes GET /requests
for the E2E spec to assert deliveries landed with the right HMAC.
Sibling pattern to MinIO. Reachable from the backend at
http://webhook-receiver:8888 inside the picpeak network.
Tests
- backend/__tests__/integration/webhookDelivery.test.js (8/8) —
signature verification, headers, retry/backoff, max-attempts → failed,
response truncation, disabled-mid-flight, SSRF block, start/stop
idempotency.
- tests/e2e/webhooks-roundtrip.spec.ts (1/1) — create webhook → trigger
event.published → assert receiver got POST with valid HMAC → visit
deliveries page → row visible with status=success → API test event →
API replay → disable webhook → assert no new delivery.
Docs
- README §"Webhooks" — event catalog, payload shape, HMAC verification
in Node + Python + bash, retry semantics, SSRF protection.
- .env.example — WEBHOOK_ALLOW_PRIVATE_URLS, WEBHOOK_DELIVERY_INTERVAL_MS,
WEBHOOK_DELIVERY_CONCURRENCY, WEBHOOK_HTTP_TIMEOUT_MS,
WEBHOOK_MAX_ATTEMPTS.
Out of scope for v1 (per issue): webhook templates' code-eval (the
${dot.path} substitution that ships is pure string replacement, no
expression engine — see follow-up commit), per-webhook rate limiting
beyond the global concurrency cap, synchronous "ask before delete"
webhooks.
Spanning files
- App.tsx pulls in this commit with both the AnalyticsBootstrap
(#325 dedup) and the WebhookDeliveriesPage route registration.
Splitting via git add -p was forfeit for sanity; the single 92-line
diff is honest about both contributions.
- adminEvents.js diff bundles the webhook fires AND the
allow_presigned_download field plumbing (#328 follow-up). Same
reasoning.
- The new webhookService/Worker/adminWebhooks files include the filter
and template logic from the follow-up — they were authored in one
pass; splitting them post-hoc would have produced fragile partial
files. The follow-up commit covers the migration and the UI for these.
Paul Nothaft
c488f481ca