services:
  db:
    image: mysql:5.7
    # Mantenim una rèplica per evitar corrupció de les dades
    # En un entorn real tirariem d'un servei especific
    deploy:
      replicas: 1
      restart_policy:
        condition: on-failure
      placement:
        constraints:
          - node.labels.role == worker
    environment:
      MYSQL_ROOT_PASSWORD: wordpress
      MYSQL_DATABASE: wordpress
      MYSQL_USER: wordpress
      MYSQL_PASSWORD: wordpress
    volumes:
      - db_data:/var/lib/mysql
    networks:
      - wp_net

  wordpress:
    image: wordpress:latest
    ports:
      - 8080:80
    environment:
      WORDPRESS_DB_HOST: db:3306
      WORDPRESS_DB_USER: wordpress
      WORDPRESS_DB_PASSWORD: wordpress
      WORDPRESS_DB_NAME: wordpress
    volumes:
     # Important: En un cluster real multi-node, això de ser un volum compartit (NFS)
      - wp_data:/var/www/html
    networks:
      - wp_net   
    deploy:
      replicas: 3
      restart_policy: 
        condition: on-failure
      placement:
        constraints:
          - node.labels.role == worker

volumes:
  db_data:
  wp_data:

networks:
  wp_net:
    driver: overlay