rocketchat unable to connect to mongodb docker container

Question

I am been trying this for a few days now. I have two container in a docker compose file. My mongodb container is running ok but my rocketchat container is unable to connect to mongodb.

This is the error log from my rocketchat container

error: 'An error occurred when creating an index for collection "users: connect ECONNREFUSED 127.0.0.1:27017'

This is my Docker-compose.yml

version: '3'
services:
  rocketchat:
    image: rocketchat/rocket.chat:latest
    ports:
      - "3000:3000"
    environment:
      - MONGO_URL=mongodb://localhost:27017/rocketchat?replicaSet=rs0
      - MONGO_OPLOG_URL=mongodb://localhost:27017/local?replicaSet=rs0
      - ROOT_URL=http://localhost:3000
      - PORT=3000:3000
    depends_on:
      - mongo
    expose:
      - 3000:3000
    restart: unless-stopped
    networks: 
      - rocketchat-network
  mongo:
    image: mongo:5
    volumes:
      - ./data:/data/db
    command: mongod --oplogSize 128 --replSet rs0
    expose:
      - 27017:27017
    restart: unless-stopped
    networks: 
      - rocketchat-network

networks:
  rocketchat-network:
    driver: bridge