docker-compose.yml example with Node.js file watching on OS X

docker-compose.yml

# Backend API service example, uses nodemon to keep server alive and watch for changes.
backendapi:
  # Tells docker-compose where ./backendapi/Dockerfile is
  build: ./backendapi
  # Allows live editing of ./backendapi/app
  volumes:
    - ./backendapi/app:/app
  # Launch Nodemon, using 
  # -L legacy file watching for compatibility with boot2docker / docker-machine. 
  # --watch defined to avoid watching the whole container and causing high CPU usage
  command: nodemon -L --watch /src/app/ /src/app/index.js
  # Expose a port to access the server locally
  ports:
   - "3000:3000"
  # So we don't have to manually restart if we cause any bugs while developing.
  restart: on-failure

# Frontend Node.js powered app example
frontend:
  build: ./frontend
  volumes:
    - ./frontend/app:/app
  # Set the working_dir so we can then execute commands
  working_dir: /app
  # This executes a script defined in package.json
  # Example React.js & browserify / watchify script compatible with Docker:
  # Setting --poll enables polling of files, 1000ms seems to not cause too higher CPU usage, set this to a higher figure if it does for you.
  # See https://github.com/substack/watchify#options for more info
  # "watchify src/App.jsx -d -t [reactify --es6] --poll=1000 -o public/bundle/app.js -v"
  command: npm run start
  # Expose a different port from the backendapi
  ports:
    - "3002:3002"
  # Linking another service automatically writes an entry in the /etc/hosts file in this container.
  # So to access the backend api server-side we can use http://backendapi:3000 or to access client-side we can use http://localhost:3000
  links:
    - backendapi:backendapi
  # Restart automatically when we break things
  restart: on-failure