wordpress + phpMySql + mySql on Docker

docker-compose.yml

version: "2"
services:
  wptest:
    image: wordpress
    ports:
      - 8080:80
    depends_on:
      - mysql
  mysql:
    image: mariadb
    environment:
      - MYSQL_ROOT_PASSWORD=examplepass
  phpmyadmin:
    image: phpmyadmin/phpmyadmin
    depends_on:
      - mysql
    ports:
      - 8181:80
    environment:
      - MYSQL_ROOT_PASSWORD=examplepass
      # use docker inspect [db container] to get the host address
      - PMA_HOST=172.20.0.2
      - PMA_PORT=3306