In this guide, you'll learn how to securely manage your MongoDB connection string using the .env file in an Express.js backend project. Let's dive in! 🚀

Step 1: Install dotenv 📦

First, install the dotenv package to read environment variables from your .env file:

npm install dotenv

Step 2: Create a .env File 🛠️

Create a .env file in the root of your project and store your MongoDB URI in it. For example:

MONGO_URI=mongodb+srv://<username>:<password>@cluster0.mongodb.net/<database>?retryWrites=true&w=majority

Replace <username>, <password>, and <database> with your actual database credentials.

Step 3: Load Environment Variables 🌐

In your main project file (e.g., index.js or app.js), import and configure dotenv at the very top:

import dotenv from 'dotenv';
dotenv.config();

This ensures that all variables in your .env file are loaded into process.env.

Step 4: Use the Environment Variable 🛡️

Now, use the environment variable MONGO_URI in your MongoDB connection:

mongoose.connect(process.env.MONGO_URI, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
})
.then(() => console.log('Connected to MongoDB'))
.catch(err => console.error('Error connecting to MongoDB:', err));

Step 5: Add .env to .gitignore 🚫

To prevent exposing sensitive data (like your MongoDB URI) in version control, add .env to your .gitignore file:

.env

Security Tip 🔒

Never hardcode sensitive information like usernames, passwords, or database URLs directly in your code. Always use environment variables for a secure and clean setup.

Full Example: index.js 📝

Here’s a complete example of an Express.js app connected to MongoDB using the .env file:

import express from 'express';
import mongoose from 'mongoose';
import cors from 'cors';
import UserRoute from './routes/UserRoute.js';
import dotenv from 'dotenv';

dotenv.config();

const app = express();

mongoose.connect(process.env.MONGO_URI, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
});

const db = mongoose.connection;
db.on('error', (error) => console.log(error));
db.once('open', () => console.log('Database Connected'));

app.use(cors());
app.use(express.json());

// Routes
app.use(UserRoute);

app.listen(5080, () => console.log('Server is running'));

Ready to Go! 🎉

If you’ve followed these steps correctly, your project should now be securely connected to MongoDB using environment variables. Happy coding! 😊

Let's Connect 🌐

• LinkedIn