System user backup-pull created on the VPS (no sudo, locked password).
authorized_keys restricted with restrict + forced command
rrsync -ro /var/backups/cayce. Verified with a since-deleted throwaway
key: no shell, no arbitrary commands, no sftp/scp, no reads outside
/var/backups/cayce, no writes; the positive rsync pull works.
authorized_keys is left EMPTY — the operator adds their real key with
the exact line documented in deploy/backup/backup-pull-setup.md.
deploy/backup/make-backup.sh (installed as /usr/local/bin/cayce-make-backup):
- pg_dump custom-format of the cayce-ops DB (URL from env or .env,
SQLAlchemy driver qualifier stripped, credentials never logged)
- gitea dump (repos + sqlite + attachments), live; consistency notes in RESTORE.md
- config tar: Caddyfile(+d), gitea app.ini + internal_token, cayce-* units, .env
- EACH artifact encrypted with age BEFORE leaving the tmpdir; recipient
read from /etc/cayce-backup/age-recipient.pub (public key only). The
private age key never touches this server.
- plaintext exists ONLY in a mktemp dir removed by an EXIT trap; a partial
day directory is removed on failure; any step failure => exit != 0 =>
journald entry
- manifest.sha256 over the encrypted artifacts (pull side verifies
integrity WITHOUT the age private key)
- destination /var/backups/cayce/YYYY-MM-DD/ (750 root:backup-pull, 640)
- retention: 7 daily dirs, pruned by mtime
systemd: cayce-backup.service (oneshot, hardened: ProtectSystem=strict,
NoNewPrivileges, ProtectHome=read-only) + cayce-backup.timer (daily
03:15 UTC, Persistent). Timer ENABLED on the VPS per operator instruction;
runs fail loudly (exit 1, clear journald message) until the age recipient
is provided — that is the designed not-configured state.
cayce