Exported docker-compose.yml from Rancher for a working wordpress cluster.

docker-compose.yml

app:
  environment:
    WORDPRESS_DB_PASSWORD: password
  external_links:
    1979c1fa-26cd-45a0-91cc-c73812fc94b5: mysql
  tty: true
  image: wordpress
  links:
  - database
  stdin_open: true
Balance:
  ports:
  - 80:80
  tty: true
  links:
  - app
  stdin_open: true
database:
  restart: on-failure:5
  environment:
    MYSQL_ROOT_PASSWORD: password
    MYSQL_DATABASE: drupal
    MYSQL_USER: drupal
    MYSQL_PASSWORD: drupal
  tty: true
  image: mysql
  stdin_open: true