This is a classic conundrum.
Containers and their volumes are supposed to be ephemeral (right?).
Yet we use them to run little apps where we configure settings etc in the app which we would like to “keep” - thus back up. Yes in a proper set up you would hook your container up to something that is not ephemeral like a database somewhere, but often we just want an app, see it’s got a self contained docker image, and just run it.
Whilst not in the spirit of things… I’ve tried using Borg backup however it just fails due to random permissions on the volumes.
I should spend more time looking into it but haven’t the time right now, could be the solution is specific to the app/container but the simplicity of just backing up a /volumes/* directory is soooo tempting…
Edit upon reflection, what about a sudo cron tab to zip volumes and set useful permissions on the zip. Then Borg to backup the zip. Borg (or at least vorta) can easily run scripts before/after and pass variables relating to the backup though.
I had no idea!
Wonder if any of that stuff will make it upstream and if not if there’s good reason?