docker-compose-prod.yaml

version: "3.8" # define the version of the Docker Compose file

services: # a 'dictionary' that defines the services that will run in containers
  prod: # a 'dictionary as the first 'key' in services; the 1st service, the dev env
    image: reactype/rt-prod # a 'key' in dev, specifying the image to use
    container_name: rt-prod # the container's name
    ports:
      - "5656:5656" # an 'array', maps port 8080 from the host to container
    # environment: # set ENV variables to MongoSQL initialization
    volumes: # a 'key' containing 'arrays'
      - .:/app/src # mounts the current directory to /usr/src/app  in the container; allows webpack-dev-server running in the container to watch for code changes in our file system outside the container; we have live reloading and HMR
      - node_modules:/app/src/node_modules # mounts a named volume, 'node_modules', to preserve our node modules
    command: npm start # run 'npm run dev:hot' inside the container to start the server
    # depends_on: # ensures that the dev service/container starts only after postgres-db service/container is up
    #   - postgres-db

  # postgres-db: # a 'dictionary'; the 2nd service, the PostgreSQL db
  #   image: spencerayleen:mm-postgres
  #   container_name: mm-database
  #   environment: # set ENV variables to PostgreSQL initialization
      # - POSTGRES_PASSWORD=admin # set user pw
      # - POSTGRES_USER=mmadmin # set user (name)
      # - POSTGRES_DB=mmdb # set db name
  #   volumes:
  #     - dev-db-volume:/var/lib/postgresql/data # mount a named volume, 'dev-db-volume', to the /var/lib/postgresql/data directory in the container where postgres stores the actual data files that make up your database; this volume will persist the data between container starts and stops

volumes: # a 'dictionary', defines named volumes to persist data
  node_modules: # empty node_modules key, will be shared between containers
  # dev-db-volume: # empty dev-db-volume key