dkruger/mysql-backup repository overview

⁠docker-mysql-backup

This is a simple docker container which can be used to create rotating backups of a MySQL database. It can be run either as a stand-alone container, or linked to another container running MySQL.

Checkout the example docker-compose.yml⁠ for an exmaple of linking the backup container to a MySQL container.

This image is based off of dkruger/cron⁠ which provides a simple cron implementation. The cron daemon is used to execute logrotate which will rotate a number of backups, using mysqldump to create a new backup file at the end of the rotation.

⁠Using the image

The image is configurable via environment variables for configuring the MySQL server, and the backup settings.

• DB_NAME: The name of the database to backup
• DB_HOST: The MySQL host to connect to, defaults to "mysql"
• DB_USER: The username for authenticating with DB_HOST, defaults to "root"
• DB_PASSWORD: The password for DB_USER, defaults to "password"
• ROTATE_COUNT: The number of backup files to keep, defaults to 8
• BACKUP_CRONTAB: The crontab time entry, defaults to weekly
• MYSQLDUMP_OPTIONS: Flags passed to mysqldump, defaults to --single-transaction
• ROTATE_UID: The UID to use for creating the backup files, defaults to 0
• ROTATE_GID: The GID to use for creating the backup files, defaults to 0

The image defines a single volume: /backup which is used to store the backup images.

Here is an example command for executing the container linked with another container called mydb which is hosting the MySQL DB we want backed up:

docker run \
    --name mydb-backup \
    --link mydb:mysql \
    -e DB_NAME="somedb" \
    -e DB_HOST="mysql" \
    -e DB_USER="someuser" \
    -e DB_PASSWORD="securepassword" \
    dkruger/mysql-backup:latest

⁠About permissions

The container utilizes logrotate to make its backups. Recent versions of logrotate have become more strict with permissions, requiring that the folder not be world-writeable, or if it is be given a user/group to su as. Because of this you may need to specify a UID and GID that will have permissions to write to the backup directory. Note that these are the ID numbers, not the names.