docker-compose.yml

version: '3.8'
services:
  # react development server
  client:
    build: ./client
    ports:
      - '3000:3000'
  # server container manages client requests
  server:
    build: ./server
    ports:
      - '9000:9000'
      # localhost:9000/ for host machine
      # server:9000/ for containers
    volumes:
      - userdata:/storage # mounted volume, contains user generated data
  # executor container responds to requests from the server container
  executor:
    build: ./executor
    # visible as executor:8080/ for other containers, but the app is hidden to the host
    volumes:
      - userdata:/storage # mounted volume, contains user generated data
volumes:
  # userdata volume common to all composed containers
  userdata:
    external: true