Edit: Results tabulated, thanks for all y’alls input!

Results fitting within the listed categories

Just do it live

Shut down all database containers

Long-ass backup script

Mythical database live snapshot command

(it seems pg_dumpall for Postgres and mysqldump for mysql (though some images with mysql don’t have that command for meeeeee))

Docker image that includes Mythical database live snapshot command (Postgres only)

New catagories

Snapshot it, seems to act like a power outage to the database

  • LVM snapshot -> backup that @[email protected]

  • ZFS snapshot -> backup that @[email protected] (real world recovery experience shows that databases act like they’re recovering from a power outage and it works)

  • (I assume btrfs snapshot will also work)

One liner self-contained command for crontab

  • One-liner crontab that prunes to maintain 7 backups, dump Postgres via pg_dumpall, zips, then rclone them @[email protected]

Turns out Borgmatic has database hooks

  • Borgmatic with its explicit support for databases via hooks (autorestic has hooks but it looks like you have to make database controls yourself) @[email protected]

I’ve searched this long and hard and I haven’t really seen a good consensus that made sense. The SEO is really slowing me on this one, stuff like “restic backup database” gets me garbage.

I’ve got databases in docker containers in LXC containers, but that shouldn’t matter (I think).

me-me about containers in containers

a me-me using the mental gymnastics me-me template; the template is split into two sections with the upper being a simple 3-step gymnastic routine while the bottom has the one being mocked flipping on gymnastic bars, using gymnastic rings, a balance beam, before finally jetpacking over a burning car. The top says "docker compose up -d" in line with the 3 simple steps of the routine, while the bottom, while becoming increasingly more cluttered, says "pass uid/gid to LXC", "add storage devices to LXC", "proxy network", "install docker on every container", and finally "docker compose up -d".

I’ve seen:

  • Just backup the databases like everything else, they’re “transactional” so it’s cool
  • Some extra docker image to load in with everything else that shuts down the databases in docker so they can be backed up
  • Shut down all database containers while the backup happens
  • A long ass backup script that shuts down containers, backs them up, and then moves to the next in the script
  • Some mythical mentions of “database should have a command to do a live snapshot, git gud”

None seem turnkey except for the first, but since so many other options exist I have a feeling the first option isn’t something you can rest easy with.

I’d like to minimize backup down times obviously, like what if the backup for whatever reason takes a long time? I’d denial of service myself trying to backup my service.

I’d also like to avoid a “long ass backup script” cause autorestic/borgmatic seem so nice to use. I could, but I’d be sad.

So, what do y’all do to backup docker databases with backup programs like Borg/Restic?

    • ikidd@lemmy.worldEnglish
      2·
      5 months ago

      While there’s probably a better way of doing it via the docker zfs driver, I just make a datastore per stack under the hypervisor, mount the datastore into the docker LXC, and make everything bind mount within that mountpoint, then snapshot and backup via Sanoid to a couple of remote ZFS pools, one local and one on zfs.rent.

      I’ve had to restore our mailserver (mysql) and nextcloud (postgres) and they both act as if the power went out, recovering via their own journaling systems. I’ve not found any inconsistencies on recovery, even when I’ve done a test restore on a snapshot that’s been backed up during known hard activitiy. I trust both databases for their recovery methods, others maybe not so much. But test that for yourself.