Node.js MongoDB Backend Boilerplate

A production-ready backend boilerplate built with Node.js, Express, and MongoDB by Mritunjai. This starter template provides a solid foundation for building scalable REST APIs with authentication, file uploads, and email functionality.

🚀 Features

• Express.js - Fast, unopinionated web framework
• MongoDB with Mongoose - NoSQL database with elegant ODM
• JWT Authentication - Secure token-based authentication
• Email Integration - Built-in Nodemailer configuration
• File Upload - Multer middleware for handling multipart/form-data
• CORS Enabled - Cross-Origin Resource Sharing configured
• Environment Variables - Secure configuration management with dotenv
• Modular Architecture - Clean separation of concerns (MVC pattern)
• Error Handling - Centralized error response utilities
• API Versioning - Structured routing with version support (v1)

📁 Project Structure

mun-b/
├── src/
│   ├── config/           # Configuration files
│   │   ├── db-config.js
│   │   ├── mail-config.js
│   │   ├── server-config.js
│   │   └── index.js
│   ├── controllers/      # Request handlers
│   ├── middlewares/      # Custom middleware
│   │   ├── validateAuthRequest.js
│   │   ├── multer.js
│   │   └── index.js
│   ├── models/           # Mongoose schemas
│   ├── repositories/     # Data access layer
│   ├── routes/           # API routes
│   │   ├── v1/
│   │   └── index.js
│   ├── services/         # Business logic
│   └── utils/            # Utility functions
│       ├── common/       # Common utilities
│       │   ├── error-response.js
│       │   └── success-response.js
│       └── errors/       # Custom error classes
├── public/
│   └── temp/             # Temporary file storage
├── .env                  # Environment variables
├── .gitignore
├── index.js              # Application entry point
├── package.json
└── README.md

🛠️ Installation

Prerequisites

• Node.js (v14 or higher)
• MongoDB (local or cloud instance)
• npm or yarn

Steps

1. Clone the repository

   git clone <repository-url>
   cd mun-b

2. Install dependencies

   npm install

3. Configure environment variables

   Create a .env file in the root directory:

   DB_URI=mongodb://localhost:27017/YourDatabaseName
   BACKEND_PORT=3001
   JWT_SECRET_KEY=your_secret_key_here
   JWT_EXPIRE=1d
   EXPIRES_IN=1d
   [email protected]
   ADMIN_EMAIL_PASSWORD=your_app_password
   ADMIN_EMAIL2=
   ADMIN_EMAIL_PASSWORD2=

4. Start MongoDB

   Make sure MongoDB is running on your system:

   # For local MongoDB
   mongod

5. Run the application

   Development mode (with nodemon):

   npm run dev

   Production mode:

   node index.js

6. Verify the server

   Open your browser or API client and navigate to:

   http://localhost:3001

   You should see: Server is running.........

🔧 Configuration

Database Configuration

Located in src/config/db-config.js

• Configures MongoDB connection URI
• Sets Mongoose options

Server Configuration

Located in src/config/server-config.js

• Port configuration
• JWT settings
• Admin email credentials

Mail Configuration

Located in src/config/mail-config.js

• Nodemailer transport setup
• Email service configuration

🔐 Authentication

This boilerplate includes JWT-based authentication middleware:

Features:

• Token Generation - JWT tokens with configurable expiration
• Token Verification - Middleware to protect routes
• Email Validation - Custom validation for NIT Hamirpur emails (@nith.ac.in)
• Authorization Headers - Bearer token authentication

Usage Example:

// Protect a route
const { checkAuth } = require('./src/middlewares/validateAuthRequest');

router.get('/protected-route', checkAuth, controller.handler);

📤 File Upload

Multer middleware is configured for handling file uploads:

Two Upload Types:

1. CSV Upload - Saves as data.csv in ./public/temp/
2. Image Upload - Saves with timestamp in ./public/temp/image/

Usage Example:

const { upload, uploadImage } = require('./src/middlewares/multer');

// CSV upload
router.post('/upload-csv', upload.single('file'), controller.handler);

// Image upload
router.post('/upload-image', uploadImage.single('image'), controller.handler);

📧 Email Service

Nodemailer is integrated for sending emails:

• Configured in src/config/mail-config.js
• Supports multiple admin email accounts
• Ready for transactional emails, notifications, etc.

🛣️ API Routes

Routes are organized with versioning support:

/api/v1/...

Add your routes in src/routes/v1/index.js

🧩 Middleware

Available Middleware:

1. validateAuthRequest - Validates authentication requests
2. checkAuth - Verifies JWT tokens
3. upload - Handles CSV file uploads
4. uploadImage - Handles image uploads

📦 Dependencies

| Package | Purpose | |---------|---------| | express | Web framework | | mongoose | MongoDB ODM | | cors | Enable CORS | | dotenv | Environment variables | | nodemailer | Email sending | | multer | File upload handling | | jsonwebtoken | JWT authentication | | http-status-codes | HTTP status constants |

🚦 API Response Format

Success Response

{
  "success": true,
  "message": "Operation successful",
  "data": { ... }
}

Error Response

{
  "success": false,
  "message": "Error message",
  "error": {
    "statusCode": 400,
    "explanation": ["Detailed error explanation"]
  }
}

📝 Development Guidelines

Adding a New Feature

1. Create Model in src/models/
2. Create Repository in src/repositories/
3. Create Service in src/services/
4. Create Controller in src/controllers/
5. Add Routes in src/routes/v1/

Best Practices

• Keep business logic in services
• Use repositories for database operations
• Validate requests in controllers
• Use middleware for cross-cutting concerns
• Follow the existing folder structure

🔒 Security Features

• JWT Authentication - Secure token-based auth
• Environment Variables - Sensitive data protection
• CORS Configuration - Controlled cross-origin access
• Password Validation - Request validation middleware
• Error Handling - Prevents information leakage

🐛 Debugging

Run with nodemon for auto-restart on file changes:

npm run dev

Check MongoDB connection:

# The console will log:
# "Connected to MongoDB" - Success
# "MongoDB not connected" - Failure

📄 License

ISC

👨‍💻 Author

Mritunjai

• Email: [email protected]

🤝 Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

📌 Notes

• Make sure to change the JWT_SECRET_KEY in production
• Update DB_URI to point to your MongoDB instance
• For Gmail SMTP, use App Passwords
• The email validation currently checks for @nith.ac.in domain - modify as needed in src/middlewares/validateAuthRequest.js

🎯 Next Steps

After setting up, you can:

1. Create your first model in src/models/
2. Set up authentication routes
3. Build your API endpoints
4. Add custom middleware as needed
5. Implement your business logic

Happy Coding! 🚀