Supported tags and respective Dockerfile links

latest (Dockerfile)

The container is based on alpine:3.9, thus it is very small.

What is schnitzler/mysqldump?

This container can be used in two ways. It is prepared to run crond by default, so you can integrate this container in your docker-compose.yml and do regularly backups defined by a crontab and backup script.

Additionaly you can use this container to create single backups. In this case scroll to the very bottom of this documentation.

Use as cronjob container

Here is an example configuration for using the container with a crontab.

Directory structure:

.
├── backup
├── bin
│   ├── backup
│   └── crontab
└── docker-compose.yml

Directory listing of the bin folder:

$ ls -al
total 16
drwxrwxr-x 2 whoami whoami 4096 Feb 25 17:51 .
drwxrwxr-x 4 whoami whoami 4096 Feb 25 17:51 ..
-rwx------ 1 root       root        175 Feb 25 17:51 backup
-rw------- 1 root       root         69 Feb 25 17:51 crontab

Mind the file permissions!
chown 0:0 backup && chmod 700 backup
chown 0:0 backup && chmod 600 crontab

docker-compose.yml

version: '2'
services:
  db:
    image: mariadb:10.1
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: password
      MYSQL_USER: user
      MYSQL_PASSWORD: password
      MYSQL_DATABASE: database
  cron:
    image: schnitzler/mysqldump
    restart: always
    volumes:
      - ./bin/crontab:/var/spool/cron/crontabs/root
      - ./bin/backup:/usr/local/bin/backup
    volumes_from:
      - backup
    command: ["-l", "8", "-d", "8"]
    environment:
      MYSQL_HOST: db
      MYSQL_USER: user
      MYSQL_PASSWORD: password
      MYSQL_DATABASE: database
  backup:
    image: busybox
    volumes:
      - ./backup:/backup

bin/crontab

#minute hour    day     month   week    command
0       0       *       *       *       /usr/local/bin/backup

bin/backup

#!/bin/sh

now=$(date +"%s_%Y-%m-%d")
/usr/bin/mysqldump --opt -h ${MYSQL_HOST} -u ${MYSQL_USER} -p${MYSQL_PASSWORD} ${MYSQL_DATABASE} > "/backup/${now}_${MYSQL_DATABASE}.sql"

Use as cronjob container (without overwriting bin/crontab)

The container has a proper crontab by default:

# do daily/weekly/monthly maintenance
# min	hour	day	month	weekday	command
*/15	*	*	*	*	run-parts /etc/periodic/15min
0	*	*	*	*	run-parts /etc/periodic/hourly
0	2	*	*	*	run-parts /etc/periodic/daily
0	3	*	*	6	run-parts /etc/periodic/weekly
0	5	1	*	*	run-parts /etc/periodic/monthly

If these execution times suffice, you can simply mount your backup script into the proper folder:

version: '2'
services:
  ...
  cron:
    image: schnitzler/mysqldump
    restart: always
    volumes:
      - ./bin/backup:/etc/periodic/daily/backup
    volumes_from:
      - backup
    command: ["-l", "8", "-d", "8"]
    environment:
      MYSQL_HOST: db
      MYSQL_USER: user
      MYSQL_PASSWORD: password
      MYSQL_DATABASE: database
  ...

Use for a single backup

In this case you simply empty the entrypoint and run the mysqlump command.

docker run \
    --rm --entrypoint "" \
    -v `pwd`/backup:/backup \
    --link="container:alias" \
    schnitzler/mysqldump \
    mysqldump --opt -h alias -u user -p"password" "--result-file=/backup/dumps.sql" database