docker-compose.yml

version: '2'
services:
  wordpress:
    container_name: my-wordpress-app
    image: wordpress
    ports: 
      - "80:80"
    environment:
      - "WORDPRESS_DB_HOST=mysql:3306"
      - "WORDPRESS_DB_PASSWORD=password"
  mysql:
    container_name: my-wordpress-database
    image: mysql
    expose:
      - "3306"
    environment:
      - "MYSQL_ROOT_PASSWORD=password"

wordpress.dsb

{
  "services": {
    "mysql": {
      "Env": [
        "MYSQL_ROOT_PASSWORD=password"
      ], 
      "Image": "mysql@sha256:a9a5b559f8821fe73d58c3606c812d1c044868d42c63817fa5125fd9d8b7b539", 
      "Networks": [
        "default"
      ], 
      "Ports": [
        {
          "Port": 3306, 
          "Protocol": "tcp"
        }
      ]
    }, 
    "wordpress": {
      "Env": [
        "WORDPRESS_DB_HOST=mysql:3306", 
        "WORDPRESS_DB_PASSWORD=password"
      ], 
      "Image": "wordpress@sha256:42e78527eda069e20ff1759286ce809d910509380e836ea97794eb5fa6311447", 
      "Networks": [
        "default"
      ], 
      "Ports": [
        {
          "Port": 80, 
          "Protocol": "tcp"
        }
      ]
    }
  }, 
  "version": "0.1"
}