database.js

import dotenv from 'dotenv';

dotenv.config();

const params = {
  username: process.env.DATABASE_USERNAME,
  password: process.env.PASSWORD,
  host: process.env.HOST,
  port: process.env.PORT,
  databaseName: process.env.DATABASENAME,
};

export const url = `mongodb://${params.username}:${params.password}@${params.host}:${params.port}/${params.databaseName}?retryWrites=true&w=majority`;
// export const url = `mongodb+srv://${params.username}:${params.password}@${params.host}/${params.databaseName}?retryWrites=true&w=majority`;

docker-compose.yml

version: '3.1'
services:
  mongo:
    image: mongo:7.0
    container_name: mongo
    environment:
      MONGO_INITDB_ROOT_USERNAME: mongadmin
      MONGO_INITDB_ROOT_PASSWORD: testtest
      MONGO_INITDB_DATABASE: my_db
    ports:
      - 27017:27017
    volumes:
      - ./.datas:/data/db

  mongo-express:
    image: mongo-express
    container_name: mongoexpress
    ports:
      - 8081:8081
    environment:
      ME_CONFIG_MONGODB_ADMINUSERNAME: mongadmin
      ME_CONFIG_MONGODB_ADMINPASSWORD: testtest
      ME_CONFIG_MONGODB_URL: mongodb://mongadmin:testtest@mongo:27017/