Log-rotation worker

/bin/rotate_log is the helper's minimal logrotate replacement, covering exactly one file: /var/log/cron.log. The full configuration surface is documented at Log rotation.

Why a dedicated worker

logrotate is not in the upstream restic/restic Alpine base. Pulling it in just for one log file is over-engineering, so the helper rolls its own: a single bash worker, wrapped in the same locked_run as every other cron entry. The worker is always scheduled (ROTATE_LOG_CRON, default Saturday 00:00).

Behaviour

Condition	Action
cron.log size ≤ CRON_LOG_MAX_SIZE	No-op; exit 0.
cron.log size > CRON_LOG_MAX_SIZE	Rename to cron_log_<timestamp>, gzip into a .tar.gz, recreate an empty cron.log.
Number of .tar.gz archives > MAX_CRON_LOG_ARCHIVES	Delete oldest extras.

The worker writes nothing to last-rotate-log.json (no JSON summary) and does not emit Prometheus metrics. It is intentionally boring.

See Log rotation for variables, manual rotation and integration with external log forwarders.