Off-host backup & restore

HealthLog ships with an optional daily off-host backup that ships every user's JSON dump, encrypted with AES-256-GCM under a SEPARATE key (BACKUP_ENCRYPTION_KEY), to any S3-compatible bucket — Cloudflare R2, AWS S3, Backblaze B2, MinIO, etc.

The backup runs at 02:30 Europe/Berlin every day from the worker container (queue data-backup-offhost). Object key layout:

<bucket>/YYYY-MM-DD/user-<userId>.json.enc

Wire format (binary)

magic   = "HLBK"           (4 bytes, ASCII)
version = 0x01             (1 byte)
iv      = 12 random bytes  (AES-GCM nonce)
authTag = 16 bytes         (AES-GCM tag)
ciphertext = N bytes       (AES-256-GCM, key = BACKUP_ENCRYPTION_KEY)
plaintext  = JSON dump (UTF-8)

Required env vars

Var	Required	Notes
`BACKUP_ENCRYPTION_KEY`	yes	64 hex chars or 32-byte base64. Different from `ENCRYPTION_KEY`.
`BACKUP_S3_ENDPOINT`	yes	e.g. `https://<account>.r2.cloudflarestorage.com`
`BACKUP_S3_BUCKET`	yes
`BACKUP_S3_ACCESS_KEY`	yes
`BACKUP_S3_SECRET_KEY`	yes
`BACKUP_S3_REGION`	no	defaults to `auto` (Cloudflare R2)
`BACKUP_RETENTION_DAYS`	no	defaults to `30`

Bucket lifecycle (recommended)

The worker prunes objects older than BACKUP_RETENTION_DAYS, but the storage provider's lifecycle rule is the canonical safety net:

Filter: "" (all objects)
Action: Expire after 30 days

For Cloudflare R2 add this from the bucket's Settings → Lifecycle.

Smoke test

After deploying, hit POST /api/admin/backup/test (admin-only). It performs a 1-byte PUT + GET round-trip and returns:

{
  "endpoint": "https://...r2.cloudflarestorage.com",
  "bucket": "healthlog-backups",
  "region": "auto",
  "putLatencyMs": 142,
  "getLatencyMs": 38,
  "ok": true
}

The credentials are never returned.

Restore

Pick a key (e.g. 2026-05-08/user-clx123.json.enc) from the bucket and run the restore script with the same backup credentials and encryption key the backup was written under — a freshly generated BACKUP_ENCRYPTION_KEY cannot decrypt any existing object:

BACKUP_S3_ENDPOINT=https://...r2.cloudflarestorage.com       \
BACKUP_S3_BUCKET=healthlog-backups                           \
BACKUP_S3_ACCESS_KEY=...                                     \
BACKUP_S3_SECRET_KEY=...                                     \
BACKUP_S3_REGION=auto                                        \
BACKUP_ENCRYPTION_KEY=<the key the backup was written under> \
pnpm dlx tsx scripts/restore-backup.ts \
  2026-05-08/user-clx123.json.enc \
  /tmp/restored.json

Run this command from a source checkout with the production backup variables exported. The script imports the full application dependency graph, which the minimal production image does not expose as an operator scripting environment.

The script downloads the object, decrypts it, and writes the JSON dump to disk. Importing the JSON back into a HealthLog instance is left to the operator (use prisma db seed or a custom script).

Monthly restore drill (automatic)

Since v1.16.4 a pg-boss job (data-restore-drill, cron 11 4 1 * * — 04:11 on the 1st of each month) exercises the read path end-to-end: fetch the most recent backup object from the bucket, decrypt it under the current BACKUP_ENCRYPTION_KEY, JSON-parse it, and sanity-check the payload shape. It performs no database restore — it validates the artefact, not the import path.

Outcomes:

Success — record counts, object age, and sizes land in the wide-event meta (job.restore_drill).
Stale chain — the newest object is older than 3 days: the nightly uploader has stalled (or the lifecycle rule is too aggressive). The drill pages via the worker error reporter (stderr + GlitchTip).
Failure — empty bucket, fetch error, decryption failure (wrong or rotated key), malformed JSON: pages the same way. A decryption failure right after a BACKUP_ENCRYPTION_KEY change means the new key cannot read the existing objects — re-encrypt or accept that pre-rotation backups are only readable with the retired key.
Not configured — deployments without the BACKUP_S3_* vars skip silently (wide-event warning only).

The drill needs no IAM grant beyond the uploader's existing GetObject + ListBucket.

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