Docker MySQL migration image

This image will automatically play a sequence of SQL scripts against an existing MySQL database. It's useful as part of a compose file to keep the schema up to date without having to delete the MySQL volume to update the schema.

Usage

Run the image setting the following environment variables:

• MYSQL_HOST
• MYSQL_USER
• MYSQL_PASSWORD
• MYSQL_DATABASE

Ensure your database container is running and link it to the container (-l)

Finally, map your directory containing migrations to /docker-entrypoint-migrations.d. Each migration should be an sql or sql.gz file and must start with migration.

Example (standalone)

docker run --link=database \
	-e MYSQL_HOST=database \
	-e MYSQL_USER=user \
	-e MYSQL_PASSWORD=password \
	-e MYSQL_DATABASE=db \
	-v $(pwd)/migrations:/docker-entrypoint-migrations.d/ \
	mathewhall/mysql_migration 

Example (compose)

database:
  image: mysql
  expose:
    - 3306
  volumes:
    - ./schema:/docker-entrypoint-initdb.d
    - /var/lib/mysql
  environment:
    MYSQL_DATABASE: database
    MYSQL_USER: user
    MYSQL_PASSWORD: password
    MYSQL_ROOT_PASSWORD: root_password

migration:
  image: mathewhall/mysql_migration
  volumes:
    - ./migrations:/docker-entrypoint-migrations.d
  links:
    - database
  environment:
    MYSQL_HOST: database
    MYSQL_DATABASE: database
    MYSQL_USER: user
    MYSQL_PASSWORD: password

Each time your containers are started via compose, the migrations will run. You can avoid repeating the environment variables using the env_file directive in your compose file to define the MySQL credentials in one place instead of two.