A WROLPi drive can move between hosts and across deployment styles
(Portable, RPi, Debian). /etc/fstab is host-specific and on the Portable
image it's part of a read-only squashfs, so persisting secondary mounts
there was both wrong-host and lost-on-reboot. This change makes
/media/wrolpi/config/fstab.yaml the single source of truth for WROLPi-
managed mounts and introduces a new wrolpi-mounts.service that reconciles
live state to match.
Architecture:
- The Controller writes intent (fstab.yaml) but never calls mount(8) or
umount(8) itself. Every mutation triggers `systemctl restart
wrolpi-mounts.service`; the Controller then verifies the outcome via
the same MountExecutor abstraction the service uses.
- wrolpi-mounts.service runs a thin entry point that constructs a real
Reconciler with a SubprocessMountExecutor and calls apply(). The
reconciler mounts what's in fstab.yaml but missing from the live state,
and unmounts paths it previously claimed that are no longer in
fstab.yaml. A managed-set file in /run/wrolpi-mounts/managed prevents
the reconciler from ever touching user-mounted paths it didn't own.
- One-time migration (marker-gated) lifts both /etc/fstab WROLPi entries
and any controller.yaml drives.mounts entries into fstab.yaml.
/etc/fstab is backed up to /etc/fstab.wrolpi-migration.backup;
migrated lines are commented in place with a "migrated to fstab.yaml:"
prefix so a host admin can hand-recover.
Test approach: dependency injection in place of patching. The
MountExecutor protocol has SubprocessMountExecutor (production) and
FakeMountExecutor (in-memory, records calls). The Reconciler accepts an
executor in its constructor, so the 20 reconciler tests + 13 migration
tests + 18 fstab_yaml tests use real files in tmp_path with zero
mock.patch calls. test_disks_api.py drops to mocks only for the
host-touching read helpers; the mount/unmount paths now run the real
Reconciler against the fake executor.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
