Lucas RayanandClaude Opus 5
2282dc96e9
Trivy failed the two images added in the previous commit. The Dockerfile rule was straightforward - neither declared a user - and both now run unprivileged, with the migrate base moved from v4.17.1 to v4.19.1 because the older one sits on Alpine 3.19 with six HIGH advisories. The rest is not fixable here. What remains in those two images is the contents of golang-migrate and Rspamd themselves: 37 and 48 fixable HIGH/CRITICAL findings that belong to those projects. Our layers add .sql and .conf files and nothing else, so gating this pipeline on them would gate it on somebody else's release cadence, and a blanket ignore rule would quietly weaken the scan for the images we do control. The image scan therefore covers the four images whose contents this project authors, with the reason stated at the step and the upstream pair recorded in OPERATIONS.md as something to watch. Both are still built in CI, so a broken Dockerfile still fails. Worth being clear: these two images were already running in the stack before this change. Putting them in the matrix made their state visible; it did not create it. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
178 lines
6.8 KiB
Markdown
178 lines
6.8 KiB
Markdown
# Operating LambdaMail
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What to watch, what the alerts mean, and how to recover. For the initial
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install see [DEPLOYMENT.md](DEPLOYMENT.md).
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## Health
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`GET /health` on the `protocols` service answers three ways, and the difference
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matters:
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| Response | Meaning |
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| :--- | :--- |
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| `200`, `X-LambdaMail-Health: ok` | Healthy |
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| `200`, `X-LambdaMail-Health: degraded` | Running, but something needs an operator. The body says what. |
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| `503` | A dependency is down — usually Postgres. |
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Degraded is deliberately not a failure: restarting cannot fix a certificate the
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proxy never issued, and a restart loop would only hide it.
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## Certificates
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Under `TLS_MODE=traefik` the mail listeners read the certificate Coolify's proxy
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manages. Two failure modes are worth understanding.
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**No certificate for the mail host.** The proxy only holds certificates for
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hosts it routes, so `mail.example.com` needs a router even though nothing is
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served over HTTP there. `docker-compose.yaml` declares one; if you removed it,
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the listeners fall back to a self-signed certificate and `/health` reports
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degraded.
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**A certificate that stopped renewing.** The watcher re-reads the store every
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60 seconds and reports:
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- `WARNING` when the soonest expiry is under 7 days
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- `CRITICAL` under 24 hours, or when it has already expired
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Watch for these in `docker compose logs protocols`. The admin console's TLS
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panel shows the same state, including when the watcher last managed to read the
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store — a timestamp that stops advancing means it has gone blind, which is the
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failure that shows up 90 days later as an expired certificate.
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## Backups
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Two things must be backed up, and **they must not live in the same place**:
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1. **The database.** `pg_dump` covers mailboxes, messages metadata, DKIM keys
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(encrypted), sessions and the queue.
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2. **`LAMBDAMAIL_MASTER_KEY`.** Every DKIM private key, TOTP secret and provider
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token in that dump is encrypted with it. A backup you cannot decrypt is not a
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backup.
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Message bodies live in the `mail_storage` volume (or S3, with
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`STORAGE_DRIVER=s3`). The database references them by hash; restoring one
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without the other leaves rows pointing at blobs that are not there.
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```bash
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# Database
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docker compose exec -T db pg_dump -U "$POSTGRES_USER" "$POSTGRES_DB" | gzip > lambdamail-$(date +%F).sql.gz
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# Message bodies
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docker run --rm -v lambdamail_mail_storage:/data -v "$PWD:/backup" \
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alpine tar czf /backup/mail-$(date +%F).tar.gz -C /data .
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```
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Restoring has not been rehearsed in this repository. Before relying on it,
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restore into a scratch environment and confirm a message opens — an untested
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restore is a hypothesis.
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## Accounts
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```bash
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make create-admin EMAIL=… PASSWORD='…' # first admin, or --force for another
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make reset-password EMAIL=… PASSWORD='…' # recovers a lockout, ends its sessions
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```
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An account locks itself for 15 minutes after 5 failed passwords. That is the
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lockout working, not a fault; `reset-password` clears it.
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If somebody loses their second factor and their recovery codes, there is no
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self-service path today. Clear the enrolment directly and have them enrol again:
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```sql
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DELETE FROM mfa_totp WHERE mailbox_id = (SELECT id FROM mailboxes WHERE email_address = 'them@example.com');
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```
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## Delivery
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The outbound queue lives in Postgres, so it survives a restart of anything. The
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retry ladder is 5 min, 15 min, 1 h, then 2/4/8/12 h with jitter, giving up after
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5 days with a bounce. A delay notice goes out at the fourth attempt.
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```sql
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-- What is stuck and why
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SELECT destination_domain, status, attempt, last_smtp_code, left(last_error, 80)
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FROM outbound_jobs WHERE status IN ('DEFERRED','BOUNCED')
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ORDER BY created_at DESC LIMIT 20;
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```
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Reading the failures:
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- **`4.7.5` with a TLS message** — the destination published a DANE or MTA-STS
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policy that could not be satisfied. The message is deferred rather than sent
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in the clear, which is the point. If it persists, the destination's
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certificate is broken, not yours.
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- **`5.1.1`** — no such recipient. Permanent, bounced immediately.
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- **A dial or connection error with no code** — the destination is unreachable;
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it will retry.
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The admin console's Queue page shows the same data with retry and cancel.
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## DNS drift
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With a Cloudflare token, the zone is reconciled on start and every six hours.
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It is idempotent, and records it did not create are reported as conflicts
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rather than overwritten.
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```bash
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docker compose logs protocols | grep -E "DNS reconcile|DNS conflict"
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```
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`PARTIAL` or `DRIFT` in that output means the desired state and the zone
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disagree — most often because a record was edited by hand.
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## Spam filtering
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Rspamd holds its state in Redis and its thresholds in `system_config`, editable
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from the admin console. The defaults reject at 15, tag at 6 and greylist at 4.
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A message the filter routes to `Junk` is filed there; one over the reject
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threshold is refused during the SMTP session, so the sender is told. Nothing is
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accepted and silently discarded — a silent discard loses legitimate mail with
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nobody aware of it.
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## Rotating a DKIM key
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From the admin console, or:
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```bash
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curl -X POST https://<host>/api/v1/admin/dkim/rotate \
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-H 'Content-Type: application/json' -b 'lm_admin_session=…' \
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-d '{"domain":"example.com","selector":"lmail2","algorithm":"rsa2048"}'
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```
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The previous key is retired with a 7-day overlap rather than deleted: mail
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already sent under it is still being verified by receivers who may take a while
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to stop resolving the old selector. **Publish the new selector's TXT record
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before the overlap ends**, or signatures start failing when the old key goes.
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## Rotating the master key
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There is no automated path today. It requires decrypting every sealed secret
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with the old key and resealing with the new one, and getting it wrong destroys
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them. Plan a maintenance window and rehearse against a copy first.
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## Upstream images
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Two images in the stack are upstream projects with our files layered on top:
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`migrations` (golang-migrate plus the schema) and `rspamd` (Rspamd plus its
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configuration). Vulnerability scanning in CI covers the four images whose
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contents this project authors; findings inside those two belong to the upstream
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project and cannot be fixed here.
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That is a decision, not an oversight: watch their releases and bump the pinned
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tags when they publish. `docker run --rm aquasec/trivy image rspamd/rspamd:3.9`
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shows where they stand at any point.
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## What is not automated
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Being explicit so nothing is assumed:
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- Backups are documented, not scheduled. Set up a cron job.
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- Restores are not rehearsed.
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- There is no metrics endpoint or alerting yet; the signals above are log lines
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and the health endpoint.
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- Master key rotation is manual.
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- Log retention is whatever Docker's json-file driver is configured for
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(10 MB × 3 per service, in `docker-compose.yaml`).
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