docker-compose.yml

version: "3.7"
x-base-service: &default-app
  image: node:20-alpine
  restart: always
  ports:
    - "3000"
  environment:
    - VIRTUAL_HOST=proxy
    - VIRTUAL_PORT=3000
  volumes:
    - "./service.js:/service.js:ro"

services:
  # This is a reverse proxy using Jason Wilder's nginx image.  You can read
  # more about it at his blog:
  #
  # http://jasonwilder.com/blog/2014/03/25/automated-nginx-reverse-proxy-for-docker/
  proxy:
    image: jwilder/nginx-proxy:1.3-alpine
    restart: always
    ports:
      - "8000:80"
    volumes:
      - "/var/run/docker.sock:/tmp/docker.sock:ro"

  # One version of a service
  service_a:
    <<: *default-app
    command: |
      node /service.js Service-A

  # A second instance to emulate an updated version of the service.  This is
  # just a copy of the first version to keep it simple.
  service_b:
    <<: *default-app
    command: |
      node /service.js Service-B

  # This simulates multiple client requests coming in continuously to the proxy.
  # Apache ab (http://httpd.apache.org/docs/current/programs/ab.html) is used
  # for simplicity's sake, and it will report the number of successful requests,
  # as well as the number of non-2xx requests, which is what we are trying to
  # keep to zero.
  ab:
    image: httpd
    depends_on:
      - proxy
    # Use a long timeout for ab so that it doesn't die
    # when the connection to the backend dies.  We want
    # it to run to for 120s with whatever number of
    # requests, thus -n10000000.
    command: |
      ab -s600 -t120 -n10000000 -c1 http://proxy/