Mongo Replica Set with Docker Compose

docker-compose.yml

version: "3"
services:
  master:
    image: mongo
    links:
      - slave
    networks:
      - mongo-cluster
    volumes:
      - ./init-repl-set.sh:/docker-entrypoint-initdb.d/init-repl-set.sh
    command: mongod --replSet replset
    ports:
      - "27017:27017"
  slave:
    image: mongo
    networks:
      - mongo-cluster
    command: mongod --replSet replset
networks:
  mongo-cluster:
    driver: bridge

init-repl-set.sh

(sleep 5 && mongo --eval "rs.initiate({_id: 'replset', members: [{_id: 0, host: 'master:27017'}, {_id: 1, host: 'slave:27017'}]})")&