Introduction

The MERN stack (MongoDB, Express.js, React.js, Node.js) is a popular choice for web applications. To ensure security and scalability, deploying it with Nginx as a reverse proxy and securing it with SSL using Certbot is a great approach. This guide will walk you through setting up Nginx for a MERN stack application and securing it with a free SSL certificate from Let's Encrypt using Certbot.

Prerequisites

Before proceeding, ensure you have the following:

• A server running Ubuntu (or any Linux distribution with Nginx support).

• A registered domain name (e.g., yourdomain.com).

• A running Node.js application on port 3000.

• Nginx installed on your server.

• Root or sudo access to the server.

Step 1: Install Nginx and Certbot

First, update your system and install Nginx along with Certbot:

sudo apt update
sudo apt install nginx certbot python3-certbot-nginx -y

Configure Nginx as a Reverse Proxy

Create an Nginx configuration file for your domain:

sudo nano /etc/nginx/sites-available/yourdomain.com

server {
    listen 80;
    server_name yourdomain.com www.yourdomain.com;

    location / {
        proxy_pass http://localhost:3000;  # Your Node.js app
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}

Save and close the file (CTRL+X, then Y, then ENTER).

Understanding sites-available and sites-enabled

Nginx uses two directories to manage site configurations:

• /etc/nginx/sites-available/: This directory stores all the available site configurations, but they are not active unless linked.

• /etc/nginx/sites-enabled/: This directory contains symbolic links to the configurations in sites-availablethat should be enabled and used by Nginx.

To enable a site, create a symbolic link:

sudo ln -s /etc/nginx/sites-available/yourdomain.com /etc/nginx/sites-enabled/

Then restart Nginx to apply the changes:

sudo nginx -t  # Test configuration
sudo systemctl restart nginx

Obtain an SSL Certificate with Certbot

Run the following command to obtain and install a free SSL certificate from Let's Encrypt:

sudo certbot --nginx -d yourdomain.com -d www.yourdomain.com

Follow the on-screen instructions to complete the SSL setup. Certbot will automatically configure Nginx to use SSL.

sudo certbot renew --dry-run

Final Nginx Configuration (With SSL)

server {
    listen 80;
    server_name yourdomain.com www.yourdomain.com;
    return 301 https://$host$request_uri;  # Redirect HTTP to HTTPS
}

server {
    listen 443 ssl;
    server_name yourdomain.com www.yourdomain.com;

    ssl_certificate /etc/letsencrypt/live/yourdomain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/yourdomain.com/privkey.pem;
    include /etc/letsencrypt/options-ssl-nginx.conf;
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;

    location / {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}

Please have a look at the below blog

 linkshttps://itdefined.org/blogs/details/72/Setting%20Up%20Nginx%20with%20Certbot%20SSL/

Git Repo Link

https://github.com/itdefined-org-apps/fullstack_mern.git