Exclude certain paths from backup

[dsp76]

As my mastodon app collected a lot of cached files, my daily backup got really big. I would love to have an option to exclude certain paths from backup. I could imagine other apps also create cache directories, which are not important to be in the backup?

[james]

Hello @dsp76
Thanks for reporting.
Instead, we should move these cache files to either runtimedirs or persistentdirs

[james]

Hello @dsp76

After some consideration I am against such a feature.
I can understand that it could be useful in some cases like this one, but we should rather fix the app itself to not include these files in the backup.
Cloudron expects everything in /app/data/ to be part of the backup/restore process.
If something gets excluded it might be fine at first.
But, it would be the user's responsibility to maintain that exclusion.

Example:
/app/data/$some_folder gets excluded from the backup.
The app decides upstream to store something in that folder that is needed for a full backup/restore process.
User has some issue, restores, app is broken, reports the issue in the forum/mail.
We'd have to analyse why a backup/restore failed, only to see it was a custom backup exclusion that caused the issue.
We would have to inform the user, it is his fault, we can't do anything to restore the app into a working state again.

This would partially shift the responsibility for working backup/restore from Cloudron to the customer and would only lead to customer dissatisfaction.

[dsp76]

Understood - so would it mean, that maintaining the mastodon app image would need to change to store cache elsewhere, not in /app/data?

[james]

Hello @dsp76
Yes.
We will look into moving these cache files outside /app/data/ so they are not included in the backup.

[nebulon]

just to not miss this, have you tried to set the cache retention lower first? https://docs.cloudron.io/packages/mastodon#cache-retention-days

That has drastically reduced the amount to backup for my instance. Worst case my instance just has to refetch when scolling the timeline