Borgbackup docker image

This is a lightweight (based on alpine) docker container image for borgbackup. It's goal is to include everything needed to run borgbackup, as a server, and as a client.

Usage - server

There are a couple of directores that we should mount inside the running container.

• /data: A good name/folder to store your backups. You can really use whatever name you want on this folder, as long as you tell borg.

• /root: At least, mount up /root/.ssh, or the authorized_keys file. You should prepend your entry in the authorized_keys with something like; command="borg serve --append-only --restrict-to-path /data",no-pty,no-agent-forwarding,no-port-forwarding,no-X11-forwarding,no-user-rc ssh-rsa AAAAB3... Or skip the --append-only. See options here⁠.

• /etc/ssh/hostkeys: We store the ssh identity files here. Mount it to keep the same sshd identity between starts.

Usage - client (untested, but should work)

You can use this docker image as a client as well, but having borg in a docker container might feel weird. When creating a backup, you define a set of paths to backup. Paths that we need to mount. Use the included borg script to start borg inside the image. You must also set your docker mountpoints in the file ${HOME}/.config/borg/docker-client.conf. The content of that file is made into 1 line, and added as additional docker parameters.

This might or might not work as you want.. You should really use your os version of the borg client, not the one in this image (even tho it's fresh from pip and contains the needed libs).

To talk to a borg server that is not on port 22, use something like this; borg init ssh://root@127.0.0.1:2222/data/important

Check out the environment variable section⁠ in the documentation for some tips of what you can set using -e.

Look here⁠ for info about pattern-matching.

Example usage

# Initialize archive
borg init -e keyfile -a -v ssh://root@10.1.2.3/data/desktop

# Make .no-regular-backup files in the folders you want to skip. Easier than --excluding them all..
touch Temp/.no-regular-backup

# Run regulary
borg create -v -s -p "ssh://root@10.1.2.3/data/desktop::{hostname}-medium-{now:%Y-%m-%d_%H:%M:%S}" \
  --exclude-if-present=.no-regular-backup \
  --exclude '*.pyc' --exclude '*/.apm' --exclude '*/.npm' --exclude '*/.gem' --exclude '*/.node-gyp' \
  --exclude '*/node_modules' --exclude '*/site-packages' --exclude '*/.Trash' --exclude '*/compile-cache' --exclude '*/*_old' \
  /Users/username

# Run once in a while
borg create -v -s -p "ssh://root@10.1.2.3/data/desktop::{hostname}-big-{now:%Y-%m-%d_%H:%M:%S}" \
 --exclude-if-present=.no-backup \
 --exclude '*.pyc' --exclude '*/node_modules' --exclude '*/.Trash' \
 /Users/username /private/etc/

FAQ

Why are there no VOLUME defined

Docker tries to set permissions on them, and it might not be able to do that in some circumstances. At least that was the case with nfs volumes on 2016-12-20.

TODO

• Use a backup user inside the container, not root