Support restic check

[SiddharthManthan]

Add support to check the repo.

The following checks are available :

• Repo Integrity
• Packfile Integrity
  • Full check --read-data
  • Specified subset of repo --read-data-subset=n/t
  • Random subset of repo
    • Random subset by percent --read-data-subset=x%
    • Random subset by size --read-data-subset=nS

The existing plans can be classified into backup plan and check plan. Check plan can be scheduled similar to backup plans.

This could be considered a high priority issue since repo can be corrupted due to updates or existing undiscovered bugs (eg : recent compression bug). If repo corruption is known soon, it can rectified.

[MarvinJWendt]

+1 from me.

Personally, I would like a Check now button, next to the Backup now one.

Also some repo configuration that would make sense:

• Check schedule (CRON like schedule for checking the repo automatically)
• Scheduled check percentage (applied to each scheduled check)
• Manuel check percentage (applied to each manual check, e.g.: click on Check now)

Thinking about it, maybe it would make sense to have a dropdown button next to Backup now with "More actions".

Maybe it would also make sense to move Unlock repo and Prune now there.
That way, we could also have a button Full check now without bloating the UI.

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Note: as a new restic user, who used backrest to back up multiple hosts with multiple TB of data, I would be very interested in seeing that a backup is restorable. Having an indicator in the UI that shows something like "Check: OK {timestamp}" would make it easy to spot corrupted backups. Also, this could be combined with notifications, when a corrupted backup is detected. Or if backrest wants to go so far, maybe even automatic fixing of corrupted backups (as I am new to restic, I am not sure if it provides functionality for repairing corrupted chunks after a failed check, I'll leave that to the pros)

[garethgeorge]

Hey, thanks all for the interest. Just updating here to say that this is high on the todo list. I like the idea of a "check now" button at the very least and will aim to make automatic checks configurable. I think the right time to run them is probably right after a prune operation.

[lakemike]

Coincidentally, I just had issues with one my repositories.

• This was identified by an automated "prune" run.
• Running "check" at commandn line confirmed there is an issue.
• A combination of "repair index" and "repair snapshots --forget" was effective in fixing it.

Just looking at this case, these enhancements could be very useful

• "check now" button
• option to run checks in a scheduled fashion or, alternatively, always after prune
• "more actions" button, e.g. "repair index", "repair packs", "repair snapshots"

[garethgeorge]

Initial implementation in PR #303 , a preview release with check support can be downloaded from https://github.com/garethgeorge/backrest/actions/runs/9260231928 .

Check is introduced as a new type of scheduled task (similar to prune) with new hooks introduced to make it's output actionable:

• CONDITION_CHECK_START
• CONDITION_CHECK_ERROR
• CONDITION_CHECK_SUCCESS

Similar hooks were also added for prune for consistency.

[garethgeorge]

Available in version 1.1.0