There are risk, that a newer version of an image will accidentally, break things, apply breaking changes and so on.
Good, frequent, tested backups, could be a mitigation to this. If an image breaks, you just restore your data from the backup, and pull the older image.
I use the klausmeyer/docker-registry-browser
, and that recently broke, but it just needed me to provide an additional configuration variable.
I use advplyr/audiobookshelf
, which upgraded to a different database engine and schema a couple months ago. For some small subset of people (including me) the migration to the new database didn’t go well. But I had a backup from 6 hours before the update, so restoring and then using the older image until the fixes were released was easy.
Even with the occasional issues I prefer letting watchtower automatically update most of my images for my home. I don’t really want to spend my time manually applying updates when 98% of the time it will be fine. But again, having a reliable and tested backup system is an essential part of why I am comfortable doing this.
My primary ‘backup’, or easy recovery method is that I use ZFS, and take snapshots via sanoid frequently. I have a mydumper jump making backups of my mariadb server. I use syncoid to doing sends to external storage. So most things can just be fixed by copying the files from an older snapshot.
I also have a completely separate backups of my system made using borg to storage I have at borgbase.com, but this only happens a couple times a week, and is only my ‘important’ data and not large things like downloaded video/music/etc. I am thinking about switching borg out for restic though, since restic is also compatible with borgbase.