Initialize custom users and databases in MongoDb

.env

# Database
MONGO_INITDB_ROOT_USERNAME=admin
MONGO_INITDB_ROOT_PASSWORD=admin
MONGO_INITDB_DATABASE=my-app-db

docker-compose.yaml

version: '3.8'
services:
  mongo:
    image: mongo:latest
    container_name: mongo
    restart: unless-stopped
    env_file:
      - ./.env
    environment:
      MONGO_INITDB_ROOT_USERNAME: ${MONGO_INITDB_ROOT_USERNAME}
      MONGO_INITDB_ROOT_PASSWORD: ${MONGO_INITDB_ROOT_PASSWORD}
      MONGO_INITDB_DATABASE: ${MONGO_INITDB_DATABASE}
    volumes:
      - mongodb-data:/data/db
      - mongodb-log:/var/log/mongodb
      - ./scripts/mongo-init.js:/docker-entrypoint-initdb.d/mongo-init.js:ro
    ports:
      - '27017:27017'
    networks:
      - mongo_net
    
  mongo-express:
    image: mongo-express
    restart: always
    ports:
      - 8081:8081
    environment:
      ME_CONFIG_MONGODB_ADMINUSERNAME: ${MONGO_INITDB_ROOT_USERNAME}
      ME_CONFIG_MONGODB_ADMINPASSWORD: ${MONGO_INITDB_ROOT_PASSWORD}
      ME_CONFIG_MONGODB_URL: mongodb://${MONGO_INITDB_ROOT_USERNAME}:${MONGO_INITDB_ROOT_PASSWORD}@mongo:27017/
    networks:
      - mongo_net

volumes:
  mongodb-data:
    driver: local
  mongodb-log:
    driver: local

networks:
  mongo_net:
    driver: bridge

mongo-init.js

db.createUser({
    user: 'app_user',
    pwd: 'app_pass',
    roles: [
      {
        role: 'dbOwner',
        db: 'my-app-db',
      },
    ],
  });