crails-backup

A command line interface tool managing several aspects of backup management.

• Backups and restores from filesystem and databases (PostgreSQL, MySQL, MongoDB)
• Schedules backups using cron
• Performs either incremental backups using bup or snapshots using tar.
• Manages the lifetime of backups files.

Installing

crails-backup uses the build2 build system, and you may use this git repository as a build2 package.

We also provide an install script which should take care of everything. Just run the following command:

bash <(curl -s "https://raw.githubusercontent.com/crails-framework/crails-backup/master/install.sh")

How to use

Performing a backup

With crails-backup, your backups consist of a name and a list of backable resources. The latter can either be filesystem pathes, or databases represented using database URLs. The following command would create a backup named my_wordpress backing a mysql database and a single folder.

crails-backup backup \
  -n my_wordpress \
  -d 'mysql://user:password@localhost/name' \
  -f /srv/my-wordpress/wp-content 

A single backup can also back multiple databases or paths at once:

crails-backup backup \
  -n my_wordpress \
  -d 'mysql://user:password@localhost/name' \
     'postgres://user:password@localhost/name' \
  -f /srv/my-wordpress/wp-content \
     /srv/my-wordpress/wp-config.php

By default, backup are stored in the /opt/crails-backup folder. Since we named our backup my_wordpress, the backup archive would be found in /opt/crails-backup/my_wordpress folder. Each backup executed under the same name will be assigned a number, and stored in the corresponding folder: as new backups as stored, older backups are removed, according to the retention strategy you've chosen.

The backup storage folder can be customized using the CRAILS_BACKUP_PATH environment variable.

Scheduling backups

Instead of directly performing a backup, crails-backup can also be used to schedule periodic backups:

crails-backup add \
  -n my_wordpress \
  -d 'mysql://user:password@localhost/name' \
  -f /srv/my-wordpress/wp-content \
  -s '5 4 * *'

This will use the cron system service to periodically perform the backup. The periodicity can be customized using the -s option, by providing a cron schedule expression.

If you wish to prevent further backups, you can unschedule them using the remove command:

crails-backup remove \
  -n my_wordpress

Listing available backups

You may list the backups available for restore using the list command:

crails-backup list -n my_wordpress

This will display a list of backup ids, along as the date and time at which the backup was performed. You may then use one of the backup id to perform a restore action.

Restoring backups

Once you've figured out which backup you want to restore, you may do so using the following command:

crails-backup restore -n my_wordpress --id 1

Wiping backups

You can remove all the backups for a given project by using the wipe command:

crails-backup wipe -n my_wordpress

Storage

By default, backups are stored in the /opt/crails-backup folder. This behavior can be changed by setting the CRAILS_BACKUP_PATH environment variable.

The bup backend also supports storing backups on a remote server (see the bup section).

Backup retention

When triggering a new backup, crails-backup also checks the available backup and remove backups which are too old. By default, backups are considered expired after 31 days.

You may change how long backups are kept around by setting the BACKUP_MAX_RETENTION variable.

Backup long-term retention

You may also set an option for long-term backups. Long-term retention happens after a duration defined by the BACKUP_LONGTERM_STARTS_AFTER environment variable has passed. By default, that value is of 1 day.

Once the backup are older than BACKUP_LONGTERM_STARTS_AFTER, crails-backup will only keep one backup for every period of 24h. That value can be customized using the BACKUP_LONGTERM_PERIODICITY environment variable.

Backup retention time format

The value of the environment variables used by the backup retention system can be expressed in seconds. You may also express it as such:

BACKUP_MAX_RETENTION="365d" # keep backups for one year
BACKUP_LONGTERM_STARTS_AFTER="31d" # starts long-term storage after one month
BACKUP_LONGTERM_PERIODICITY="4d2h30m' # long-term storage keeps one backup every 4 days, 2 hours and 30 minutes

Using environment variables in scheduled backups

When scheduling backups using crails-backup add, you need to set the environment variables in your crontab. Use the crontab -e command and append the environment variables at the top of the file.

For instance:

LD_LIBRRAY_PATH="/usr/local/lib"
CRAILS_BACKUP_PATH="/backup-store"
CRAILS_BACKUP_SERVERNAME="bup-server-hostname"
BACKUP_MAX_RETENTION="365d"
BACKUP_LONGTERM_STARTS_AFTER="31d"
BACKUP_LONGTERM_PERIODICITY="2d"
5 4 * * /usr/bin/crails-backup backup -n my_wordpress -d 'mysql://user:password@localhost/name' -f /srv/my-wordpress/wp-content #name=my_wordpress

Backends

crails-backup provides two different backends:

• Incremental backups using bup
• Snapshots backups using tar

If the bup command is available, the bup backend will be used by default. Otherwise, it will fallback to the tar backend.

Bup

Remote storage

The bup backend can run the bup command with the -r option, storing the backups at a remote server (see bup's README for details on how to sett up a bup server). The SERVERNAME can be customized using the CRAILS_BACKUP_SERVERNAME environment variable. The remote server will store the backups according to the CRAILS_BACKUP_PATH environment variable from the client process performing the backup.

Tar

Compressors

The tar backend compresses the snapshot using gzip. You may use other compressors by setting the CRAILS_BACKUP_COMPRESSOR environment variable. Available values are gzip bzip2 and xz.