Zero to Up and Running a Project with Rails - docker-compose.yml with PostgreSQL

docker-compose.yml

version: "2"

services:
  web:
    build: .
    volumes:
      - .:/app
      - bundle_path:/bundle
    environment:
      - BUNDLE_PATH=/bundle/vendor
      - BUNDLE_APP_CONFIG=/app/.bundle
    user: railsuser
    command: bundle exec rails server -b 0.0.0.0
    ports:
      - "3000:3000"
    links:
      - db

  db:
    image: postgres
    volumes:
      - db:/var/lib/postgresql/data
    expose:
      - '5432'

volumes:
  bundle_path:
  db: