docker-compose.yml

version: '3.1'
services:
  mongodb:
    image: mongo:4.0.0-xenial
    volumes:
      - './mongodb:/data/db'
    networks:
      - backend
    deploy:
      placement:
        constraints: [node.role == manager]
    environment:
      MONGO_INITDB_ROOT_USERNAME: <username>
      MONGO_INITDB_ROOT_PASSWORD: <password>
    ports:
      - "27017:27017"
networks:
  backend:
    external: true