How to Create a NodeJS Login System Backend with Express and MongoDB - #1

Introduction

In this tutorial, we will create a backend login system using Node.js, Express, and MongoDB. This guide will walk you through setting up the server, connecting to a MongoDB database, and creating user APIs for login and signup functionality. By the end, you will have a foundational backend system that you can expand upon for your applications.

Step 1: Work Structure Setup

• Create a new directory for your project.
• Open your terminal and navigate to the project directory.
• Initialize a new Node.js project by running:

  yarn init -y
  

  or

  npm init -y
  

• Install necessary packages:

  yarn add express mongoose dotenv cors
  

  or

  npm install express mongoose dotenv cors
  

Step 2: MongoDB Setup

• Create a MongoDB account at MongoDB Atlas.
• Set up a new cluster and create a database.
• Obtain the connection string for your database. This will be used to connect your backend to MongoDB.

Step 3: DB Connection with Mongoose

• Create a new file called db.js in your project directory.
• Use the following code to connect to your MongoDB database:

  const mongoose = require('mongoose');
  const dotenv = require('dotenv');
  
  dotenv.config();
  
  const connectDB = async () => {
      try {
          await mongoose.connect(process.env.MONGODB_URI, {
              useNewUrlParser: true,
              useUnifiedTopology: true,
          });
          console.log('MongoDB connected');
      } catch (error) {
          console.error('MongoDB connection error:', error);
          process.exit(1);
      }
  };
  
  module.exports = connectDB;
  

Step 4: Creating the Server with Express

• Create a file named server.js.
• Set up the Express server with the following code:

  const express = require('express');
  const connectDB = require('./db');
  
  const app = express();
  connectDB();
  
  app.use(express.json());
  
  const PORT = process.env.PORT || 5000;
  app.listen(PORT, () => {
      console.log(`Server is running on port ${PORT}`);
  });
  

Step 5: Running the Server

• To run your server, use the command:

  node server.js
  

• Ensure that you see the message indicating the server is running and MongoDB is connected.

Step 6: API Routes Setup

• Create a folder named routes.
• Inside the routes folder, create a file called user.js.
• Define your user routes in user.js:

  const express = require('express');
  const router = express.Router();
  
  // Define routes for signup and login here
  // Example: router.post('/signup', signupHandler);
  
  module.exports = router;
  

Step 7: Creating the Mongoose User Model

• Create a folder named models.
• Inside the models folder, create a file called User.js.
• Define the user schema in User.js:

  const mongoose = require('mongoose');
  
  const userSchema = new mongoose.Schema({
      name: {
          type: String,
          required: true,
          match: /^[a-zA-Z ]*$/
      },
      email: {
          type: String,
          required: true,
          unique: true,
          match: /^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$/
      },
      password: {
          type: String,
          required: true,
      }
  });
  
  const User = mongoose.model('User', userSchema);
  module.exports = User;
  

Conclusion

In this first part of creating a Node.js login system, we have set up our project structure, connected to MongoDB, and created the basic server with Express. The next steps will involve implementing the user signup and login functionalities. Make sure to test your APIs using Postman as you proceed.

For further enhancements, consider adding validation, password hashing, and error handling to improve the security and robustness of your application.