Akram Khan

Posted on Oct 31

A secure authentication in nodejs with mongodb database.

#node #mongodb #javascript #express

Node.js Package Reference Guide

Core Dependencies

Web Framework & Server

express (^4.18.2)
- Web application framework
- Handles routing, middleware, and HTTP requests/responses
- Core foundation for building APIs and web applications

Database

mongoose (^7.0.0)
- MongoDB object modeling tool
- Provides schema-based solution to model application data
- Handles database operations and relationships

Security Packages

jsonwebtoken (^9.0.0)
- Creates and verifies JSON Web Tokens (JWT)
- Used for user authentication and secure information exchange
bcryptjs (^2.4.3)
- Hashes and compares passwords securely
- Protects user passwords in the database
helmet (^6.0.1)
- Adds security headers to HTTP responses
- Protects against common web vulnerabilities
- Sets various HTTP headers for security
cors (^2.8.5)
- Enables Cross-Origin Resource Sharing
- Controls which domains can access your API
- Essential for web applications with separate frontend/backend

Validation & Configuration

joi (^17.9.0)
- Data validation library
- Validates request bodies, query parameters, and other inputs
- Ensures data integrity and format
dotenv (^16.0.3)
- Loads environment variables from .env file
- Manages configuration settings
- Keeps sensitive data secure

Development Dependencies

Development Tools

nodemon (^2.0.22)
- Monitors file changes during development
- Automatically restarts the server
- Improves development workflow

Usage Example

// Express server setup
const express = require('express');
const app = express();

// Security middleware
const helmet = require('helmet');
const cors = require('cors');
app.use(helmet());
app.use(cors());

// Environment variables
require('dotenv').config();

// Database connection
const mongoose = require('mongoose');
mongoose.connect(process.env.MONGODB_URI);

// Validation example
const Joi = require('joi');
const schema = Joi.object({
    email: Joi.string().email().required()
});

// Password hashing
const bcrypt = require('bcryptjs');
const hashedPassword = await bcrypt.hash('password', 10);

// JWT authentication
const jwt = require('jsonwebtoken');
const token = jwt.sign({userId: 123}, process.env.JWT_SECRET);

Complete Node.js and Mongoose Project Structure Guide

Project Structure

project-root/
├── src/
│   ├── config/
│   │   ├── database.js
│   │   └── config.js
│   ├── models/
│   │   ├── user.model.js
│   │   └── product.model.js
│   ├── controllers/
│   │   ├── user.controller.js
│   │   └── product.controller.js
│   ├── routes/
│   │   ├── user.routes.js
│   │   └── product.routes.js
│   ├── middleware/
│   │   ├── auth.middleware.js
│   │   └── error.middleware.js
│   ├── utils/
│   │   ├── logger.js
│   │   └── validators.js
│   └── app.js
├── .env
├── .gitignore
└── package.json

1. Initial Setup

package.json

{
  "name": "node-mongoose-project",
  "version": "1.0.0",
  "main": "src/app.js",
  "scripts": {
    "start": "node src/app.js",
    "dev": "nodemon src/app.js"
  },
  "dependencies": {
    "express": "^4.18.2",
    "mongoose": "^7.0.0",
    "dotenv": "^16.0.3",
    "joi": "^17.9.0",
    "jsonwebtoken": "^9.0.0",
    "bcryptjs": "^2.4.3",
    "cors": "^2.8.5",
    "helmet": "^6.0.1"
  },
  "devDependencies": {
    "nodemon": "^2.0.22"
  }
}

.env

PORT=3000
MONGODB_URI=mongodb://localhost:27017/your-database
JWT_SECRET=your-secret-key
NODE_ENV=development

.gitignore

node_modules/
.env
logs/
*.log

2. Configuration Setup

src/config/config.js

require('dotenv').config();

module.exports = {
    port: process.env.PORT || 3000,
    mongoUri: process.env.MONGODB_URI,
    jwtSecret: process.env.JWT_SECRET,
    nodeEnv: process.env.NODE_ENV || 'development',
    jwtExpiresIn: '1d'
};

src/config/database.js

const mongoose = require('mongoose');
const config = require('./config');
const logger = require('../utils/logger');

const connectDB = async () => {
    try {
        await mongoose.connect(config.mongoUri, {
            useNewUrlParser: true,
            useUnifiedTopology: true
        });
        logger.info('MongoDB connected successfully');
    } catch (error) {
        logger.error('MongoDB connection error:', error);
        process.exit(1);
    }
};

module.exports = connectDB;

3. Models Definition

src/models/user.model.js

const mongoose = require('mongoose');
const bcrypt = require('bcryptjs');
const jwt = require('jsonwebtoken');
const config = require('../config/config');

const userSchema = new mongoose.Schema({
    name: {
        type: String,
        required: [true, 'Name is required'],
        trim: true,
        minlength: 3,
        maxlength: 50
    },
    email: {
        type: String,
        required: [true, 'Email is required'],
        unique: true,
        lowercase: true,
        trim: true
    },
    password: {
        type: String,
        required: [true, 'Password is required'],
        minlength: 6,
        select: false
    },
    role: {
        type: String,
        enum: ['user', 'admin'],
        default: 'user'
    }
}, {
    timestamps: true
});

// Pre-save middleware to hash password
userSchema.pre('save', async function(next) {
    if (!this.isModified('password')) return next();
    this.password = await bcrypt.hash(this.password, 12);
    next();
});

// Instance methods
userSchema.methods.generateAuthToken = function() {
    return jwt.sign(
        { id: this._id, role: this.role },
        config.jwtSecret,
        { expiresIn: config.jwtExpiresIn }
    );
};

userSchema.methods.comparePassword = async function(candidatePassword) {
    return await bcrypt.compare(candidatePassword, this.password);
};

const User = mongoose.model('User', userSchema);
module.exports = User;

src/models/product.model.js

const mongoose = require('mongoose');

const productSchema = new mongoose.Schema({
    name: {
        type: String,
        required: true,
        trim: true
    },
    price: {
        type: Number,
        required: true,
        min: 0
    },
    description: String,
    category: {
        type: String,
        required: true
    },
    createdBy: {
        type: mongoose.Schema.Types.ObjectId,
        ref: 'User',
        required: true
    }
}, {
    timestamps: true
});

const Product = mongoose.model('Product', productSchema);
module.exports = Product;

4. Controllers

src/controllers/user.controller.js

const User = require('../models/user.model');
const { validateUser } = require('../utils/validators');
const logger = require('../utils/logger');

exports.register = async (req, res) => {
    try {
        const { error } = validateUser(req.body);
        if (error) return res.status(400).json({ error: error.details[0].message });

        const user = await User.create(req.body);
        const token = user.generateAuthToken();

        res.status(201).json({
            status: 'success',
            token,
            data: { user }
        });
    } catch (error) {
        logger.error('Registration error:', error);
        res.status(400).json({
            status: 'fail',
            message: error.message
        });
    }
};

exports.login = async (req, res) => {
    try {
        const { email, password } = req.body;

        const user = await User.findOne({ email }).select('+password');
        if (!user || !(await user.comparePassword(password))) {
            return res.status(401).json({
                status: 'fail',
                message: 'Invalid email or password'
            });
        }

        const token = user.generateAuthToken();
        res.json({
            status: 'success',
            token
        });
    } catch (error) {
        logger.error('Login error:', error);
        res.status(400).json({
            status: 'fail',
            message: error.message
        });
    }
};

5. Routes

src/routes/user.routes.js

const express = require('express');
const router = express.Router();
const userController = require('../controllers/user.controller');
const auth = require('../middleware/auth.middleware');

router.post('/register', userController.register);
router.post('/login', userController.login);
router.get('/profile', auth, userController.getProfile);

module.exports = router;

6. Middleware

src/middleware/auth.middleware.js

const jwt = require('jsonwebtoken');
const config = require('../config/config');
const User = require('../models/user.model');

module.exports = async (req, res, next) => {
    try {
        const token = req.headers.authorization?.replace('Bearer ', '');

        if (!token) {
            return res.status(401).json({
                status: 'fail',
                message: 'No token provided'
            });
        }

        const decoded = jwt.verify(token, config.jwtSecret);
        const user = await User.findById(decoded.id);

        if (!user) {
            return res.status(401).json({
                status: 'fail',
                message: 'User not found'
            });
        }

        req.user = user;
        next();
    } catch (error) {
        res.status(401).json({
            status: 'fail',
            message: 'Invalid token'
        });
    }
};

src/middleware/error.middleware.js

const logger = require('../utils/logger');

module.exports = (err, req, res, next) => {
    logger.error(err.stack);

    if (err.name === 'ValidationError') {
        return res.status(400).json({
            status: 'fail',
            message: err.message
        });
    }

    if (err.code === 11000) {
        return res.status(400).json({
            status: 'fail',
            message: 'Duplicate field value'
        });
    }

    res.status(err.status || 500).json({
        status: 'error',
        message: err.message || 'Internal server error'
    });
};

7. Utils

src/utils/logger.js

const winston = require('winston');
const config = require('../config/config');

const logger = winston.createLogger({
    level: config.nodeEnv === 'development' ? 'debug' : 'info',
    format: winston.format.combine(
        winston.format.timestamp(),
        winston.format.json()
    ),
    transports: [
        new winston.transports.File({ filename: 'logs/error.log', level: 'error' }),
        new winston.transports.File({ filename: 'logs/combined.log' })
    ]
});

if (config.nodeEnv === 'development') {
    logger.add(new winston.transports.Console({
        format: winston.format.simple()
    }));
}

module.exports = logger;

src/utils/validators.js

const Joi = require('joi');

exports.validateUser = (user) => {
    const schema = Joi.object({
        name: Joi.string().min(3).max(50).required(),
        email: Joi.string().email().required(),
        password: Joi.string().min(6).required(),
        role: Joi.string().valid('user', 'admin')
    });

    return schema.validate(user);
};

exports.validateProduct = (product) => {
    const schema = Joi.object({
        name: Joi.string().required(),
        price: Joi.number().min(0).required(),
        description: Joi.string(),
        category: Joi.string().required()
    });

    return schema.validate(product);
};

8. Main Application File

src/app.js

const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const config = require('./config/config');
const connectDB = require('./config/database');
const errorMiddleware = require('./middleware/error.middleware');
const userRoutes = require('./routes/user.routes');
const productRoutes = require('./routes/product.routes');
const logger = require('./utils/logger');

// Initialize express app
const app = express();

// Connect to MongoDB
connectDB();

// Middleware
app.use(helmet());
app.use(cors());
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// Routes
app.use('/api/users', userRoutes);
app.use('/api/products', productRoutes);

// Error handling
app.use(errorMiddleware);

// Start server
app.listen(config.port, () => {
    logger.info(`Server running in ${config.nodeEnv} mode on port ${config.port}`);
});

// Handle unhandled promise rejections
process.on('unhandledRejection', (err) => {
    logger.error('UNHANDLED REJECTION! Shutting down...');
    logger.error(err.name, err.message);
    process.exit(1);
});

Running the Application

Install dependencies:

npm install

Set up your environment variables in .env
Start the development server:

npm run dev

For production:

npm start

Testing the API

Test the API endpoints using tools like Postman or curl:

# Register a new user
curl -X POST http://localhost:3000/api/users/register \
  -H "Content-Type: application/json" \
  -d '{"name": "John Doe", "email": "john@example.com", "password": "password123"}'

# Login
curl -X POST http://localhost:3000/api/users/login \
  -H "Content-Type: application/json" \
  -d '{"email": "john@example.com", "password": "password123"}'

This structured guide provides a complete setup for a Node.js and Mongoose application with proper organization, error handling, and security features. Each file has its specific responsibility, making the codebase maintainable and scalable.