.docker-compose.yml

version: '3'
services:
  db:
    image: postgres
    volumes:
      - postgres-data:/var/lib/postgresql/data
  app: &app
    build: .
    image: some-app
    command: bundle exec rails s -p 3000 -b '0.0.0.0'
    volumes:
      - .:/workdir
      - app-gems:/gems
    ports:
      - "3000:3000"
    depends_on:
      - db
    environment:
        RAILS_ENV: development
  test:
    <<: *app
    image: some-app:test
    command: bundle exec rake
    environment:
        RAILS_ENV: test
volumes:
  postgres-data:
  app-gems: