Incus keeper

This project is covering backup and sync scenarios for Incus instances.

• Backups instances into Restic repository
• Syncs instances to another incus instance

It handles automatic backups

KV

Functions of Sentinel depends on user KV values configured on each instance. Here is what you can configure:

Key	Default	Purpose
user.backup	false	true/false, if true, regular backup job into Restic is performed
user.sync	false	true/false, if true, regular sync job into Restic is performed
user.backup-notify-url	""	Call this URL when backup is done
user.sync-notify-url	""	Call this URL when sync is done
user.backup-schedule	0 6 * * *	Cron-like line for backup scheduling
user.sync-schedule	0 6 * * *	Cron-like line for sync scheduling
user.sync-target-remote	""	Sync's target host (needs to be configured in Incus)
user.sync-target-pool	pool0	Target's storage pool
user.sync-target-instance-suffix	-cold	Instance name suffix at the target side

It can also backup and sync volumes, here is list of KV fields for them:

Key	Default	Purpose
user.backup	false	true/false, if true, regular backup job into Restic is performed
user.backup-mode	dir	dir or native, dir backs up directory of the volume, native uses incus export
user.sync	false	true/false, if true, regular sync job into Restic is performed
user.backup-notify-url	""	Call this URL when backup is done
user.sync-notify-url	""	Call this URL when sync is done
user.backup-schedule	0 6 * * *	Cron-like line for backup scheduling
user.sync-schedule	0 6 * * *	Cron-like line for sync scheduling
user.sync-target-remote	""	Sync's target host (needs to be configured in Incus)
user.sync-target-pool	pool0	Target's storage pool
user.sync-target-volume-suffix	-cold	Volume name suffix at the target side

Examples

Enabled sync and backup on existing instance:

incus config set <instance name> user.backup=true user.sync=true user.sync-target-remote=<remote_host>

Important notes

Only one backup or sync job can run the same time. There is internal queue of jobs that is picked up one by one. Cli commands sync and backup are independent from this queue.

Restic needs two environment variables to be set:

• RESTIC_PASSWORD
• RESTIC_REPOSITORY

Also its binary needs to be available on the system where sentinel is running.

Sentinel uses Incus's CLI interface, not its API. Currently it can work only on the same machine where Incus is running.

Synced instances have sync and backup flags disabled so if the remote system runs sentinel too it won't interfere with configuration of the main location.

Volumes can be backed up in two ways. The first one is a snapshot and backup of directory where the snapshot is located. The second way is Incus's native export where a binary blob or an archive is exported and stored in Restic repo. In this case it can be imported back with incus import feature.

Volumes are synced including snapshots and refresh is used in case the destination volume exists.