Add `rig db dump <container> [outfile]` and
`rig db restore <artifact> <container> [db] [--yes]` — imperative on-box
PostgreSQL tooling, the interactive counterpart to the scheduled,
declarative `coolify backup install`.
Key decisions:
- Dumps carry `--clean --if-exists --no-owner --no-acl`. `--no-owner
--no-acl` is mandatory for cross-instance restores: the target's
superuser differs (Coolify randomizes it), so a plain dump aborts under
ON_ERROR_STOP=1 on the first GRANT/ALTER OWNER for a missing role.
- $POSTGRES_USER/$POSTGRES_DB are read INSIDE the container (single-quoted
`sh -c`), never hardcoded to `postgres` on the host.
- restore connects as the container's own superuser and runs with
ON_ERROR_STOP=1; the optional [db] arg targets a NAMED database in a
shared container, passed in via a container env var rather than string
splicing.
- restore overwrites the target, so it prompts y/N; --yes/--force is the
automation bypass. Artifact existence/non-emptiness is checked before
the confirm gate and before anything touches the DB.
- dump uses pipefail + a sibling temp promoted only on success, and
refuses to keep an empty artifact — a failed pg_dump must never leave a
plausible-looking .gz behind.
Args are validated before the root check (testable without root); guards
are root, Debian-family warn, docker, and gzip/gunzip. Adds CLI tests and
a `### rig db` README section.
Closes#15
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>