Borgmatic Container

Description

A little container I wrote to automate my Borgbackup's using the excellent Borgmatic.

It uses cron to run the backups at a time you can configure in data/borgmatic.d/crontab.txt.

Usage

To set your backup timing and configuration, you will need to create crontab.txt and your borgmatic config.yaml and mount these files into the /etc/borgmatic.d/ directory. When the container starts it creates the crontab from crontab.txt and starts crond. By cloning this repo in /opt/docker/, you will have a working setup to get started.

If using remote repositories mount your .ssh to /root/.ssh within the container.

If you want to mail the results from cron:

Add your mail relay details to the env file or mount your own [msmtprc](https://wiki.alpinelinux.org/wiki/Relay_email_to_gmail_(msmtp,_mailx,_sendmail) to /etc/msmtprc
Add add your mail address to crontag.txt e.g. MAILTO=log@example.com

Example run command

docker run \
  --detach --name borgmatic \
  -v /home:/mnt/source:ro \
  -v /opt/docker/docker-borgmatic/data/repository:/mnt/borg-repository \
  -v /opt/docker/docker-borgmatic/data/borgmatic.d:/etc/borgmatic.d/ \
  -v /opt/docker/docker-borgmatic/data/.borgmatic:/root/.borgmatic \
  -v /opt/docker/docker-borgmatic/data/.config/borg:/root/.config/borg \
  -v /opt/docker/docker-borgmatic/data/.ssh:/root/.ssh \
  -v /opt/docker/docker-borgmatic/data/.cache/borg:/root/.cache/borg \
  -e TZ=Europe/Berlin \
  b3vis/borgmatic

While the parameters above are sufficient for regular backups, following additional privileges will be needed to mount an archive as FUSE filesystem:

--cap-add SYS_ADMIN \
--device /dev/fuse \
--security-opt label:disable \
--security-opt apparmor:unconfined

Depending on your security system, --security-opt parameters may not be neccessary. label:disable is needed for SELinux, while apparmor:unconfined is needed for AppArmor.

To init the repo with encryption, run:

docker exec borgmatic \
sh -c "borgmatic --init --encryption repokey-blake2"

Layout

/mnt/source

Your data you wish to backup. For some safety you may want to mount read-only. Borgmatic is running as root so all files can be backed up.

/mnt/borg-repository

Mount your borg backup repository here.

/etc/borgmatic.d

Where you need to create crontab.txt and your borgmatic config.yml

To generate an example borgmatic configuration, run:

docker exec borgmatic \
sh -c "cd && generate-borgmatic-config -d /etc/borgmatic.d/config.yaml"

crontab.txt example: In this file set the time you wish for your backups to take place default is 1am every day. In here you can add any other tasks you want ran

0 1 * * * PATH=$PATH:/usr/bin /usr/bin/borgmatic --stats -v 0 2>&1

/root/.borgmatic

A non-volatile path for borgmatic to store database dumps. Only needed if you are using that feature.

/root/.config/borg

Here the borg config and keys for keyfile encryption modes are stored. Make sure to backup your keyfiles! Also needed when encryption is set to none.

/root/.ssh

Mount either your own .ssh here or create a new one with ssh keys in for your remote repo locations.

/root/.cache/borg

A non-volatile place to store the borg chunk cache.

Environment

Time zone, e.g. TZ="Europe/Berlin"'.
SSH parameters, e.g. BORG_RSH="ssh -i /root/.ssh/id_ed25519 -p 50221"
BORG_RSH="ssh -i /root/.ssh/id_ed25519 -p 50221"
Repository passphrase, e.g. BORG_PASSPHRASE="DonNotMissToChangeYourPassphrase"
Your mail relay host MAIL_RELAY_HOST=mail.example.com
Port of your mail relay MAIL_PORT=587
Username used to log in into your relay service MAIL_USER=borgmatic_log@example.com
Password for relay login MAIL_PASSWORD=SuperS3cretMailPw
From part in your log mail MAIL_FROM=borgmatic

Docker Compose

Prepare your configuration
1. cp .env.template .env
2. Set your environment and adapt volumes as needed
To start the container for backup: docker-compose up -d
For backup restore:
1. Stop the backup container: docker-compose down
2. Run an interactive shell: docker-compose -f docker-compose.yml -f docker-compose.restore.yml run borgmatic
3. Fuse-mount the backup: borg mount /mnt/borg-repository <mount_point>
4. Restore your files
5. Finally unmount and exit: borg umount <mount_point> && exit.
In case Borg fails to create/acquire a lock: borg break-lock /mnt/repository

likeablob / docker-borgmatic