a-quest/deploy/task3/docker-compose.yml

version: '3'
services:
  backend3:
    build:
      dockerfile: ./task3-backend/Dockerfile
      context: ../..
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock"
      - "./postbox:/app/postbox"
      - "../../keys/letter:/app/letter"
    restart: unless-stopped
    ports:
      - "31337:31337"
    networks:
      net:
        ipv4_address: 10.103.204.3

networks:
  net:
    external:
      name: tasks-net