Docker Compose is A Changing.

docker_changing.yml

version: '2'
services:
  db:
    image: kiasaki/alpine-postgres
    volumes:
      - ./pgdata:/pgdata
    environment:
      POSTGRES_DB: some_db
      POSTGRES_USER: postgres
      PGDATA: /pgdata
    ports:
      - 5432:5432
    networks:
      - backend
  web:
    image: braidn/ruby-full-stack:2.3.1
    command: bundle exec rails server -p 3000 -b '0.0.0.0'
    tty: true
    stdin_open: true
    environment:
      DATABASE_URL: db://postgres@db/some_db
    depends_on:
      - db
    volumes:
      - .:/src/repo
      - ./keys:/root/.ssh/
    volumes_from:
      - bundle_cache
      - npm_cache
    ports:
      - 3000:3000
    networks:
      - backend
  npm_cache:
    image: busybox
    volumes:
      - /src/repo/node_modules
  bundle_cache:
    image: busybox
    volumes:
      - /src/repo/.bundle
networks:
  backend: