example of docker-compose YAML file

docker-compose.yml

version: "3.5"
services:
  redis:
    image: redis:latest
    networks:
    - dev
  mysql:
    image: mysql:latest
    environment:
      MYSQL_USER: myuser
      MYSQL_PASSWORD: password
    volumes:
      - mysql-db: /var/lib/mysql
    networks:
    - dev
  app:
    image: simple:14
    environment:
      MYSQL_USER: myuser
      MYSQL_PASSWORD:
      MYSQL_DATABASE: db
      MYSQL_HOST: mysql
    networks:
      - dev
networks:
  dev:
volumes:
  mysql-db: