Criando a rede

$ docker network create --subnet=172.50.50.0/16 devnetwork

docker-compose.yml

version: '3'

services:
  mongo-express:
    container_name: mongo-express
    image: mongo-express:VERSION_HERE
    ports:
      - 7018:8081
    environment:
      ME_CONFIG_BASICAUTH_USERNAME: admin
      ME_CONFIG_BASICAUTH_PASSWORD: docker
      ME_CONFIG_MONGODB_PORT: 27017
      ME_CONFIG_MONGODB_ADMINUSERNAME: root
      ME_CONFIG_MONGODB_ADMINPASSWORD: docker
    links:
      - mongo
    networks:
      mongo-network:
        ipv4_address: 172.50.50.135

  mongo:
    container_name: mongo
    image: mongo:VERSION_HERE
    environment:
      MONGO_INITDB_DATABASE: mydatabase
    ports:
      - 7017:27017
    volumes:
      - mongo-data:/data/db
    networks:
      mongo-network:
        ipv4_address: 172.50.50.137

networks:
  mongo-network:
    external:
      name: devnetwork

volumes:
  mongo-data:

Customizando configurações

 mongo:
    container_name: mongo
    image: mongo:4.0
    environment:
      MONGO_INITDB_DATABASE: mydatabase
      MONGO_INITDB_ROOT_USERNAME: root
      MONGO_INITDB_ROOT_PASSWORD: docker
    ports:
      - 7017:27017
    volumes:
      - ./config/init-mongo.js:/docker-entrypoint-initdb.d/init-mongo.js:ro <==== AQUI ENTRA O ARQUIVO DE CUSTOMIZAÇÃO
      - mongo-data:/data/db

Arquivo init-mongo.js

db.createUser(
    {
        user: "root",
        pwd: "docker",
        roles: [
            {
                role: "readWrite",
                db: "mydatabase"
            }
        ]
    }
)

Clusters MongoDB no Docker

• https://github.com/minhhungit/mongodb-cluster-docker-compose
• https://github.com/minhhungit/mongodb-cluster-docker-compose/blob/master/docker-compose.yml

Exemplo de docker-compose.yml

version: '2'
services:

## Router
  router01:
    image: mongo:4.0
    container_name: rydell-router-01
    command: mongos --port 27017 --configdb rs-config-server/configsvr01:27017,configsvr02:27017,configsvr03:27017 --bind_ip_all
    ports:
      - 27117:27017
    volumes:
      - ./scripts:/scripts
  router02:
    image: mongo:4.0
    container_name: rydell-router-02
    command: mongos --port 27017 --configdb rs-config-server/configsvr01:27017,configsvr02:27017,configsvr03:27017 --bind_ip_all
    volumes:
      - ./scripts:/scripts
    ports:
      - 27118:27017
    links:
      - router01

## Config Servers
  configsvr01:
    image: mongo:4.0
    container_name: rydell-mongo-config-01 
    command: mongod --port 27017 --configsvr --replSet rs-config-server
    volumes:
      - ./scripts:/scripts 
    ports:
      - 27119:27017
    links:
      - shard01-a
      - shard02-a
      - shard03-a
  configsvr02:
    image: mongo:4.0
    container_name: rydell-mongo-config-02 
    command: mongod --port 27017 --configsvr --replSet rs-config-server
    volumes:
      - ./scripts:/scripts
    ports:
      - 27120:27017
    links:
      - configsvr01
  configsvr03:
    image: mongo:4.0
    container_name: rydell-mongo-config-03 
    command: mongod --port 27017 --configsvr --replSet rs-config-server
    volumes:
      - ./scripts:/scripts
    ports:
      - 27121:27017
    links:
      - configsvr02

## Shards
  ## Shards 01
   
  shard01-a:
    image: mongo:4.0
    container_name: rydell-shard-01-node-a
    command: mongod --port 27017 --shardsvr --replSet rs-shard-01
    volumes:
      - ./scripts:/scripts
    ports:
      - 27122:27017
    links:
      - shard01-b
      - shard01-c
  shard01-b:
    image: mongo:4.0
    container_name: rydell-shard-01-node-b
    command: mongod --port 27017 --shardsvr --replSet rs-shard-01
    volumes:
      - ./scripts:/scripts
    ports:
      - 27123:27017
  shard01-c:
    image: mongo:4.0
    container_name: rydell-shard-01-node-c
    command: mongod --port 27017 --shardsvr --replSet rs-shard-01
    volumes:
      - ./scripts:/scripts
    ports:
      - 27124:27017

  ## Shards 02
  shard02-a:
    image: mongo:4.0
    container_name: rydell-shard-02-node-a
    command: mongod --port 27017 --shardsvr --replSet rs-shard-02
    volumes:
      - ./scripts:/scripts
    ports:
      - 27125:27017
    links:
      - shard02-b
      - shard02-c
  shard02-b:
    image: mongo:4.0
    container_name: rydell-shard-02-node-b
    command: mongod --port 27017 --shardsvr --replSet rs-shard-02
    volumes:
      - ./scripts:/scripts
    ports:
      - 27126:27017
  shard02-c:
    image: mongo:4.0
    container_name: rydell-shard-02-node-c
    command: mongod --port 27017 --shardsvr --replSet rs-shard-02
    volumes:
      - ./scripts:/scripts
    ports:
      - 27127:27017

  ## Shards 03
  shard03-a:
    image: mongo:4.0
    container_name: rydell-shard-03-node-a
    command: mongod --port 27017 --shardsvr --replSet rs-shard-03
    volumes:
      - ./scripts:/scripts
    ports:
      - 27128:27017
    links:
      - shard03-b
      - shard03-c
  shard03-b:
    image: mongo:4.0
    container_name: rydell-shard-03-node-b
    command: mongod --port 27017 --shardsvr --replSet rs-shard-03
    volumes:
      - ./scripts:/scripts
    ports:
      - 27129:27017
  shard03-c:
    image: mongo:4.0
    container_name: rydell-shard-03-node-c
    command: mongod --port 27017 --shardsvr --replSet rs-shard-03
    volumes:
      - ./scripts:/scripts
    ports:
      - 27130:27017