Clever Geek Handbook

Configuring Restic with systemd on Linux

Restic is a well known backup software. It's simple enough to be ported to any OS, and that's probably why it doesn't come with a full example setup on an average Linux system. Let's fix it with this post.







Let's set the problem as follows:







  1. Automatic backup runs daily.
  2. The backup only stores important files and data.
  3. The backup also includes the contents of the PostgreSQL databases, which can be restored psql -f



    .


TL; DR post

/ systemd, restic CAP_DAC_READ_SEARCH



, PostgreSQL pg_dumpall



.







This assumes that the backup is done on an Ubuntu Server 20.04 machine and is being performed on a rest-server running on 192.168.1.200



. However, the configuration is trivially adaptable to any cloud provider. It also assumes that the repository has already been initialized by the command restic -r rest:http://192.168.1.200/your-repo/ init



.







Backing up files / directories



It is undesirable to run software with superuser rights unnecessarily, so let's create a separate user for our tasks restic



without a group and command shell:







# useradd -m -N -s /usr/sbin/nologin restic


We need the following systemd service with a parameter and a timer to it:







/etc/systemd/system/restic@.service



:







[Unit]
#      @,   
#   systemctl start restic@your-repo.service
# %I  "your-repo"
Description=Restic backup on %I
After=syslog.target
After=network-online.target

[Service]
Type=oneshot
User=restic
#        /etc/restic/your-repo.files
ExecStart=/usr/local/bin/restic backup --files-from /etc/restic/%I.files
#      /etc/restic/your-repo.env
EnvironmentFile=/etc/restic/%I.env
#  restic  capability DAC_READ_SEARCH,  
#      Linux,    
# ,      
#  
AmbientCapabilities=CAP_DAC_READ_SEARCH

[Install]
WantedBy=multi-user.target


/etc/systemd/system/restic@.timer



:







[Unit]
# ,      @
# (restic@your-repo.timer),  restic@your-repo.service
Description=Run Restic at 12:00 AM

[Timer]
#  restic   12  
OnCalendar=*-*-* 12:00:00

[Install]
WantedBy=timers.target


/etc/restic/your-repo.env



. systemd root, /etc/restic/



(.. 700 root



):







RESTIC_PASSWORD=your_repo_password
RESTIC_REPOSITORY=rest:http://192.168.1.200/your-repo/


/ /etc/restic/your-repo.files



:







/var/lib/docker
/etc/postgresql
/etc/restic
...


PostgreSQL



Restic , , pg_dumpall



. systemd ExecStart



execve(3)



, /usr/local/bin/pgdump.sh



:







#!/usr/bin/env bash

set -euo pipefail

/usr/bin/sudo -u postgres pg_dumpall --clean \
    | gzip --rsyncable \
    | /usr/local/bin/restic backup --host $1 --stdin \
        --stdin-filename postgres-$1.sql.gz


/etc/systemd/system/restic-pg@.service



:







[Unit]
Description=Restic PostgreSQL backup on %I
After=syslog.target
After=network-online.target
After=postgresql.service
Requires=postgresql.service

[Service]
Type=oneshot
User=restic
ExecStart=/usr/local/bin/pgdump.sh %I
EnvironmentFile=/etc/restic/%I.env

[Install]
WantedBy=multi-user.target


/etc/systemd/system/restic-pg@.timer



:







[Unit]
Description=Run Restic on PostgreSQL at 12:00 AM

[Timer]
OnCalendar=*-*-* 0:00:00

[Install]
WantedBy=timers.target




Let's start the timers and enable their autoload:







# systemctl enable --now restic@your-repo.timer restic-pg@your-repo.timer


Let's check if the built system works:







# systemctl start restic@your-repo.service
# systemctl start restic-pg@your-repo.service


This set of units allows you to back up to an unlimited number of repositories, you just need to create the appropriate ones /etc/restic/repo-name.{env,files}



.







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