mongo-rep-set.yml

    version: "3"
    services:
      mongo1:
        hostname: mongo1
        container_name: localmongo1
        image: mongo:4.0-xenial
        environment:
          MONGO_INITDB_ROOT_USERNAME: root
          MONGO_INITDB_ROOT_PASSWORD: root
          MONGO_INITDB_DATABASE: blog
        volumes:
          - ./mongo-initdb.d:/docker-entrypoint-initdb.d
        ports:
          - "27017:27017"
        restart: always
        command: --bind_ip_all --replSet rs0
      mongo2:
        hostname: mongo2
        container_name: localmongo2
        image: mongo:4.0-xenial
        ports:
          - "27018:27017"
        restart: always
        command: --bind_ip_all --replSet rs0
      mongo3:
        hostname: mongo3
        container_name: localmongo3
        image: mongo:4.0-xenial
        ports:
          - "27019:27017"
        restart: always
        command: --bind_ip_all --replSet rs0