docker-backup

A tool to create & restore complete, self-contained backups of Docker containers

What's the issue

Docker services usually have a bunch of volatile data volumes that need to be backed up. Backing up an entire (file)system is easy, but often enough you just want to create a backup of a single (or a few) containers, maybe to restore them on another system later.

Some services, such as databases, also need to be aware (flushed/synced/paused) of an impending backup. The backup should be run on the Docker host, as you don't want to have a backup client configured & running in every single container either, since this would add a lot of maintenance & administration overhead.

docker-backup directly connects to Docker, analyzes a container's mounts & volumes, and generates a list of dirs & files that need to be backed up on the host system. This also collects all the metadata information associated with a container, so it can be restored or cloned on a different host, including its port-mappings and data volumes.

The generated list can either be fed to an existing backup solution or docker-backup can directly create a .tar image of your container, so you can simply copy it to another machine.

Installation

docker-backup requires Go 1.11 or higher. Make sure you have a working Go environment. See the install instructions.

docker-backup works with Docker hosts running Docker 18.02 (API version 1.36) and newer.

Packages

• Arch Linux: docker-backup

From source

git clone https://github.com/muesli/docker-backup.git
cd docker-backup
go build

Run docker-backup --help to see a full list of options.

Usage

Creating a Backup

To backup a single container start docker-backup with the backup command and supply the ID of the container:

docker-backup backup <container ID>

This will create a .json file with the container's metadata, as well as a file containing all the volumes that need to be backed up with an external tool like restic or borgbackup.

If you want to directly create a .tar file containing all the container's data, simply run:

docker-backup backup --tar <container ID>

You can also backup all running containers on the host with the --all flag:

docker-backup backup --all

To backup all containers (regardless of their current running state), run:

docker-backup backup --all --stopped

With the help of --launch you can directly launch a backup program with the generated file-list supplied as an argument:

docker-backup backup --all --launch "restic -r /dest backup --password-file pwfile --tag %tag --files-from %list"

Restoring a Backup

To restore a container, run docker-backup with the restore command:

docker-backup restore <backup file>

docker-backup will automatically detect whether you supplied a .tar or .json file and restore the container, including all its port-mappings and data volumes.

If you want to start the container once the restore has finished, add the --start flag:

docker-backup restore --start <backup file>