version: '3' services: mysql: image: mysql:5.7 ports: - "3307:3306" environment: - MYSQL_ALLOW_EMPTY_PASSWORD=yes app: environment: BUNDLE_PATH: 'bundle' MYSQL_DB_HOST: 'mysql' build: docker/app volumes: - .:/app - ~/.gem/credentials:/root/.gem/credentials - bundle-vol:/bundle:cached command: irb tty: true stdin_open: true depends_on: - mysql volumes: bundle-vol: