Q:

How to import a database into a Docker container using docker-compose

I am working with the official WordPress Docker image with docker-compose on my Mac (using boot2docker). I need to do a one-off data import. I'm not sure how to do this. How can I import data to the database container?
wordpress:
  image: wordpress
  links:
    - db:mysql
  ports:
    - 8080:80
  volumes:
    - .:/var/www/html/wp-content/themes/my-theme-name

db:
  image: mariadb
  environment:
    MYSQL_ROOT_PASSWORD: example

A:

When using official Wordpress image, default name of the created database is wordpress.
So after you have deployed Wordpress application with docker-compose, you can import your wordpress database by
docker exec -i db mysql -uroot -pexample wordpress < dump.sql

A:

See this doc http://depressiverobot.com/2015/02/19/mysql-dump-docker.html and also this previous on SO Setting up MySQL and importing dump within Dockerfile

