Alpine Remote Backup

Introduction

Alpine remote backup (RBU) is a set of scripts based on LBU (Alpine Local Backup). It consist of a main script which need to be run from cron and a set of profiles which can be used as pre/post scripts for LBU. The idea of profiles is to simplify the backup process and to make sure services inside Alpine infrastructure are setup in a similar way. Some of the features/profiles of RBU are:

Dump databases to a cache directory
Synchronise backups to remote location
Copy backup status log to remote location
Send status notifications over mqtt

The alpine-backup script itself takes care of capturing the logs, creating the snapshot, and updating the status for monitoring. Other tasks such uploading the backup should be done through profiles. See the Minimal Setup section for details.

Prerequisite

POSIX shell
LBU (default on Alpine installation)
rsync apk add rsync
mosquitto-pub apk add mosquitto-clients

Usage

Configuration

RBU needs a configuration file named rbu.conf. This configuration should (by default) be put in the lbu configuration directory /etc/lbu. Inside this configuration should be a list of exported configuration variables which are needed for lbu and its pre/post scripts to function properly.

Profiles

Profiles are a set of LBU pre/post scripts. To use these scripts you should symlink (or copy) them from the profile directory to one of the following dirs:

/etc/lbu/pre-package.d (scripts run before LBU creates its backup)
/etc/lbu/post-package.d (scripts run after LBU created its backup)

These profiles/scripts will be run by busybox run-parts which means they cannot have an extension and need to be executable. If you need to run these scripts in a specific order you should prefix them with a number like 10-scriptname.

Minimal setup

The profiles/ directory contains some default profiles which can be used to setup basic back-ups.

At the minimum, you want to add the backup-sync script in the post-package.d directory to actually upload the backup archive to the remote server in the homedir of the user provided in rbu.conf.

backup-list can be placed in the pre-package.d directory to generate a list of files that are being backed up, which will added to the log.

Encryption

To make sure the backups are safe we use openssl encryption option provided by LBU. Please make sure you provide a secure password in rbu.conf and make sure you have a backup of that password in case you will need it when restoring.

Include non etc files

By default LBU will only backup files located in the /etc directory and have been modified. To include other files you need to lbu_include files and directories. Exclusion is possible via lbu_exclude. Please check Alpine wiki for more information regarding LBU usage.

Backup server

Backups will be kept in the specified backup location in rbu.conf. After the backup is successful these backups will be rsynced to the remote backup server. To be able to automatically rsync backups a ssh key needs to be generated per backup. For generating a Ed25519 key exec: ssh-keygen -t ed25519 and copy the public key to the backup server.

Enable daily backups

Copy the provided alpine-backup to /etc/periodic/daily to make the backup run every night.

Retention

LBU is configured to keep 7 days of backups. If you also want a monthly backup, enable the backup-archive profile in post-package.d and make sure that it’s run after the backup-sync profile. This will copy the last created backup at the first of each month to the month/ directory..

Backup monitoring

Backups are are automatically monitored by Alpine monitoring system. After the backup has finished it will send a message with metadata to our mqtt server which will be picked up by Alpine monitoring system.

NOTE

Older version of LBU have a bug which prevents the cleanup of older local encrypted backups. see: https://git.alpinelinux.org/cgit/alpine-conf/commit/?id=cd395b