what is a good solution to keep a music folder backed up

syncthing (file sync, update: removed this, not needed, actually need a backup solution)

Backup solution, you could use Borg or Restic, they are CLI, but there are also GUI for them

how can I back up my Docker setup in case I screw it up and need to set it all up again?

learn to use Dockage to replace Portainer (done, happy with this)

If you did the switch to Dockge, it might be because you prefer having your docker compose files accessible easily on the filesystem, the question is if you have the persistent data of your containers in bind mounts as well, so they are easy to backup.

I have a git repo of my stacks folder, with all my docker compose files (secrets on env files that are ignored), so that I can track all changes made to them.

Also, I have a script that stops every container while I’m sleeping and triggers backups of the stacks folder and all my bind mount folders, that way I have a daily/weekly backup of all my stuff, and in case something breaks, I can roll back from any of these backups and just docker compose up, and I’m back on track.

An important step, is to frequently check that backups are good, I do this by stopping my main service and running from a different folder with the backed up compose file and bind mounts