Introduction

This docker project brings the small and simple backup solution borg to your computer.

Installation

Retrieve the docker image via docker pull.

% docker pull silviof/docker-borgbackup

How to run

This backup system is controlled via borgctl script from this repository. Alternatively the controlling script can and should be acquired via docker run --rm silviof/docker-borgbackup get_borgctl. The used script must be the same as the script in the container. Configuration is done via an ini-file. You can get an example ini file via docker run --rm silviof/docker-borgbackup get_ini. For this you need the shini ini file parser located at /usr/bin/shini.sh. You can get a copy with docker run --rm silviof/docker-borgbackup get_shini.

docker run --rm silviof/docker-borgbackup get_borgctl > borgctl
docker run --rm silviof/docker-borgbackup get_ini > borgbackup.ini
docker run --rm silviof/docker-borgbackup get_shini > shini
chmod u+x borgctl

You have two choices to save you data. The first one is to backup on a local file storage/mounted device and the second one is a backup via ssh/sftp protocol and a borg server. Both are possible with this docker backup solution.

You can control the running docker container with some environment variables.

• BORGBACKUP_DOCKER_RUN_SHELL_OPTION change the docker run call for shell. Default is -ti --rm.
• BORGBACKUP_DOCKER_RUN_BACKUP_OPTION change the docker run call for backup. Default is --rm --sig-proxy.
• BORGBACKUP_DOCKER_RUN_SERVER_OPTION change the docker run call for server. Default is --rm --name=backupserver.

The docker container needs some more data like your ssh-key or/and a connection to the ssh-agent to work correctly. The container is started via sudo (configurable) and privileged to allow backup of data which isn't owned by the user starting the container. All folders which are not stores are mounted in read-only mode.

a simple example (installation, inifile and backup)

For a simple example let us assume we need to backup everything under /development folder without the /development/archive subfolder. We do our backup everyday at 12 o`clock and hold the backups for the last 7 days. Our backup folder is mounted in /media/sde3. The backup should be placed into the BACKUP folder of this device.

The first step is to have a borgbackup.ini file. The contents should be something like this:

[GENERAL]
REPOSITORY = "file:///media/sde3"
FOLDER = "/backupuser"
SSHKEY = /home/user/.ssh/id_rsa
ENCRYPTION = "AVeryVeryVeryVeryAndVeryVeryVeryLongishSecureWordHere"
SUDO = 1
FILECACHE = /home/user/.cache/borgbackup
VERBOSE = 1
STAT = 1
RESTOREDIR = /storage/restore

[BACKUP001]
PATH = /development
EXCLUDE = /development/archive
COMPRESSION = zlib,6
KEEPWITHIN = 1w

Now we should initialize the backup store via borgctl shell command. After that we should be dropped into a container configured for work with borg.

$ borgctl shell ~/borgbackup.ini
-+> sudo docker run -ti [...] silviof/docker-borgbackup do_shell
-+> borg environment loaded
-+> $BORG_REPO and $BORG_PASSPHRASE are set
$

We can now work with the borg command...

$ borg --help
usage: borg [-h]

            {serve,init,check,change-passphrase,create,extract,rename,delete,list,mount,info,prune,upgrade,help}
            ...

[...]

We should know that $BORG_REPO, $BORG_PASSPHRASE are set and that all folders for backup are mounted at the /BACKUP directory.

$ echo $BORG_REPO
/STORAGE//backupuser
$ ls $BORG_REPO
ls: cannot access /STORAGE//sfr: No such file or directory
$ ls /BACKUP/
/development

As we see the storage isn't initialized. We have to do this now. borg needs some options like password, compression etc. because we have set $BORG_REPO and $BORG_PASSPHRASE we don't need to specify the complete folder path and the password.

$ borg init -e repokey
Initializing repository at ""
Key in "<Repository /STORAGE/backupuser>" created.
Keep this key safe. Your data will be inaccessible without it.
Synchronizing chunks cache...
Archives: 0, w/ cached Idx: 0, w/ outdated Idx: 0, w/o cached Idx: 0.
Done.
$ ls $BORG_REPO
README  config  data  hints.0  index.0  lock.roster

The storage is now initialized.

The second step is to try to do the backup by hand. Using the borgctl script it is very simple. (example output)

$ borgctl backup ~/borgbackup.ini
-+> sudo docker run [...] silviof/docker-borgbackup do_backup

-+> BACKUP for 001 ...
-+> borg create -s -v -C zlib,6 -e /development/archive   ::development-201510231842060200 /BACKUP//development
d /BACKUP/development
[...]
------------------------------------------------------------------------------
Archive name: ::development-201510231842060200
Archive fingerprint: 1698bc896eb8c1bd0e4de84e4ddffc2402adad47d44c67eb5691ae04853fccf0
Start time: Fri Oct 23 18:42:07 2015
End time: Fri Oct 23 18:42:17 2015
Duration: 9.33 seconds
Number of files: 5

                       Original size      Compressed size    Deduplicated size
This archive:                  362 B                411 B                411 B
All archives:                  362 B                411 B                411 B

                       Unique chunks         Total chunks
Chunk index:                       2                    2
------------------------------------------------------------------------------
-+> PRUNE  for 001 ...
-+> borg prune -p developmenttftp -s -v --keep-within 1w
Keeping archive: development-201510231842060200       Fri Oct 23 18:42:07 2015

                       Original size      Compressed size    Deduplicated size
Deleted data:                    0 B                  0 B                  0 B
All archives:                  362 B                411 B                411 B

                       Unique chunks         Total chunks
Chunk index:                       2                    2

After controlling that all desired folders and files are backed up, we can configure automatic backup via cronjob.

Add this to your cronjob via crontab -e:

12 * * * * borgctl backup ${HOME}/borgbackup.ini