Ansible Role: mikroways.restic

This role was inspired by the excelent article from Jack Henschel, Restic Backups with Systemd and Prometheus exporter. I've also found an inspiration from other existing roles as: arsillio.restic but evolving from cron to systemd was my objective, so I've decided to write this new role as a composition of ideas.

This documentation needs to be updated with changes introduced since 2.0.x

Description

This role installs Restic and configures as many backup tasks to make backupsC as defined, each with its corresponding restic repo.

So the fact is that you will be using this role to:

• Install restic
• Setup restic repos, named repo1, repo2, repo3
• Setup restic backup scripts to backup data from your system into some of the previously defined repos. Each of this backup scripts can then be used in different ways:
  • Manually
  • From a systemd timer

Using systemd timer is more like using cronjobs. The main difference is the potencial systemd provides as ordering services, for example to mount a automount a filesystem previous to runing a backup script, drift randomly a scheduled task so not all tasks run at the same time (RandomizedDelaySec), and many other features that makes this a decoupled solution. Moreover, with systemd we can manage faiures, so when a backup failed we can manage what to do!

Backup Scripts

This role will create as many backup scripts as you define. For each defined backup, you will get three scripts:

• One with restic credentials
• Other with restic backup script and eventually a repository initialization
• The last one will prune your backups

This scripts will be stored in a configurable scripts directory: restic_script_dir.

Requirements

• bzip2

Role Variables

Name	Default	Description
restic_url	undefined	The URL to download restic from. Use this variable to overwrite the default
restic_version	'0.12.0'	The version of Restic to install
restic_download_path	'/opt/restic'	Download location for the restic binary
restic_install_path	'/usr/bin'	Install location for the restic binary
restic_script_dir	'{{ restic_download_path }}/restic'	Location of the generated backup scripts
restic_repos	{}	A dictionary of repositories where snapshots are stored
restic_backups	{} (or [])	A list of dictionaries specifying the files and directories to be backed up
restic_create_systemd_timer	false	Configure systemd timer or not
restic_dir_owner	{{ ansible_user }}	User id to configure restic script folder
restic_dir_group	{{ ansible_user }}	Group id to configure restic script folder
restic_access_template	restic_access.j2	Template to load used restic variables in backup scripts
restic_backup_template	restic_backup.j2	Template script to make backups
restic_prune_template	restic_prune.j2	Template script ro prune backups
restic_systemd_timer_template	systemd_timer.unit.j2	Template for systemd timer unit
restic_systemd_service_template	systemd_service.unit.j2	Template for systemd restic backup service called by timer
restic_systemd_failure_service_template	systemd_failure.unit.j2	Template for systemd on error handling
restic_systemd_failure_service_name	restic-backup-failure@.service	Name of systemd service to handle errors
restic_prometheus_exporter_enabled	false
restic_prometheus_exporter_template	restic_prometheus_exporter.j2
restic_prometheus_exporter_script	{{ restic_script_dir }}/restic_prometheus_exporter.sh
restic_prometheus_exporter_metrics_basedir	/var/lib/node-exporter
restic_failure_template	restic_failure_unit.j2
restic_failure_script	{{restic_script_dir }}/unit-failure
restic_failure_mail_to	root
restic_non_root_setup	false	Installs Restic as a specific user with read-only rights. (See restic docs)
restic_non_root_setup_user	restic
restic_gomaxprocs	not defined	By default, restic uses all available CPU cores. Use this variable to limit the number of used CPU cores.

Repos

Restic stores data in repositories. You have to specify at least one repository to be able to use this role. A repository can be local or remote (see the official documentation).

Using an SFTP repository

For using an SFTP backend, the user needs passwordless access to the host. Please make sure to distribute ssh keys accordingly, as this is outside of the scope of this role.

Available variables:

Name	Required	Description
location	yes	The location of the Backend. Currently, Local, SFTP, S3 and B2 are supported
password	yes	The password used to secure this repository
aws_access_key	no	The access key for the S3 backend
aws_secret_access_key	no	The secret access key for the S3 backend
aws_default_region	no	The desired region for the S3 backend
b2_account_id	no	The account ID for Backblaze B2 backend
b2_account_key	no	The account key for Backblaze B2 backend
Repo will be initialized if it is not done.

Example:

restic_repos:
  local:
    location: /srv/restic-repo
    password: securepassword1
  remote:
    location: sftp:user@host:/srv/restic-repo
    password: securepassword2

Backups

A backup specifies a directory or file to be backuped. A backup is written to a Repository defined in restic_repos.

Available variables:

Name	Required (Default)	Description
name	yes	The name of this backup. Used together with pruning and scheduling and needs to be unique.
repo	yes	The name of the repository to backup to.
src	yes	The source directory or file
stdin	no	Is this backup created from a stdin?
stdin_cmd	no (yes if stdin == true)	The command to produce the stdin.
stdin_filename	no	The filename used in the repository.
tags	no	Array of default tags
keep_last	no	If set, only keeps the last n snapshots.
keep_hourly	no	If set, only keeps the last n hourly snapshots.
keep_daily	no	If set, only keeps the last n daily snapshots.
keep_weekly	no	If set, only keeps the last n weekly snapshots.
keep_monthly	no	If set, only keeps the last n monthly snapshots.
keep_yearly	no	If set, only keeps the last n yearly snapshots.
keep_within	no	If set, only keeps snapshots in this time period.
keep_tag	no	If set, keep snapshots with this tags. Make sure to specify a list.
prune	no (false)	If true, the restic forget command in the script has the --prune option appended.
schedules	no ([])	Array of calendar event expressions as explained here
exclude	no ({})	Allows you to specify files to exclude. See Exclude for reference.

Example:

restic_backups:
  data:
    name: data
    repo: remote
    src: /path/to/data
    schedules:
            -  "*-*-* 02,16:45:00"

Exclude

the exclude key on a backup allows you to specify multiple files to exclude or files to look for filenames to be excluded. You can specify the following keys:

exclude:
    exclude_cache: true
    exclude:
        - /path/to/file
    iexclude:
        - /path/to/file
    exclude_file:
        - /path/to/file
    exclude_if_present:
        - /path/to/file

Please refer to the use of the specific keys to the documentation.

Full backup without root

As explained in the Restic official docs, the tool can be used without root. To have it installed as the docs are describing, set the desired user for Restic, e.g. restic:

restic_non_root_setup: true
restic_non_root_setup_user: restic
restic_dir_owner: restic
restic_dir_group: restic

Dependencies

none

Example Playbook

- hosts: all
  roles:
    - role: mikroways.restic
      become: true

Author

• Christian Rodriguez

License

This project is under the MIT License. See the LICENSE file for the full license text.

Copyright

(c) 2022, Mikroways