docker-compose

version: '3'
services:
  tracker:
    build: .
    expose:
      - "5000"
  nginx:
    image: nginx:latest
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf
    devices:
      - tracker
    ports:
      - "80:80"

tracker 服务启动3个实例

docker-compose up --scale tracker=3