steve-todorov / restic-systemd-units

restic systemd units

This is a collection of systemd units for managing backups with restic.

Installing

To install the systemd units and associated support files:

make && sudo make install && sudo systemctl daemon-reload

What gets installed?

A bunch of systemd units:

/etc/systemd/system/restic-backup-daily@.timer
/etc/systemd/system/restic-backup-monthly@.timer
/etc/systemd/system/restic-backup@.service
/etc/systemd/system/restic-backup.target
/etc/systemd/system/restic-backup-weekly@.timer

/etc/systemd/system/restic-check-daily@.timer
/etc/systemd/system/restic-check-monthly@.timer
/etc/systemd/system/restic-check@.service
/etc/systemd/system/restic-check-weekly@.timer

/etc/systemd/system/restic-forget-daily@.timer
/etc/systemd/system/restic-forget-monthly@.timer
/etc/systemd/system/restic-forget@.service
/etc/systemd/system/restic-forget.target
/etc/systemd/system/restic-forget-weekly@.timer

/etc/systemd/system/restic-prune-daily@.timer
/etc/systemd/system/restic-prune-monthly@.timer
/etc/systemd/system/restic-prune@.service
/etc/systemd/system/restic-prune.target
/etc/systemd/system/restic-prune-weekly@.timer

And this tmpfiles.d configuration, which ensures that /run/restic and /var/cache/restic exist:

/etc/tmpfiles.d/restic.conf

And a helper script, used for manually running restic against the backup profiles used by these units:

/usr/local/bin/restic-helper

Configuration

Put environment variables common to all your backups in /etc/restic/restic.conf. For example, on my system I have:

# A pointer to your restic password. This can be set globally here
# or per-backup profile.
RESTIC_PASSWORD_FILE=/etc/restic/password

Create one or more backup profiles as subdirectories of /etc/restic. For example, if you're going to be backing up /home, you might create /etc/restic/home with the following configuration in /etc/restic/home/restic.conf:

# What to back up?
BACKUP_DIR=/home

# Where to store backups?
RESTIC_REPOSITORY=/mnt/backups

# Arguments for the backup command
RESTIC_BACKUP_ARGS="--tag home"

# Arguments for the forget command
RESTIC_FORGET_ARGS="--tag home --keep-daily 2 --keep-weekly 2 --keep-monthly 1"

Enabling backups

Assuming that you have /etc/restic/home configured as above, then to schedule daily backups of /home:

systemctl enable --now [e-mail]

Or to schedule weekly backups:

systemctl enable --now [e-mail]

Similarly, if you want to run the corresponding forget task daily:

systemctl enable --now [e-mail]

And so on for prune tasks.

Lockfiles

These units use the flock binary to serialize multiple instances of the same template unit. This means if you start two backups in parallel...

systemctl start restic-backup@home restic-backup@database

...they will actually run one after the other instead of running at the same time.

Manually running restic commands

The restic-helper command reads the environment configuration from /etc/restic/restic.conf and the current directory. You can use this if you want to manually run restic commands against one of your backup profiles. For example:

# cd /etc/restic/home
# restic-helper restic snapshots
* reading configuration from /etc/restic/restic.conf
* reading configuration from ./restic.conf
password is correct
ID        Date                 Host    Tags        Directory
----------------------------------------------------------------------
1dc1d283  2018-03-03 00:00:37  myhost  home        /home
9dbd3830  2018-03-04 00:00:46  myhost  home        /home
8938235d  2018-03-05 00:00:40  myhost  home        /home
----------------------------------------------------------------------
3 snapshots