Nginx reverse proxy setup on ubuntu

Launch ubuntu instance on aws

Install node.js

# Download and install nvm:
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.3/install.sh | bash

# in lieu of restarting the shell
\. "$HOME/.nvm/nvm.sh"

# Download and install Node.js:
nvm install 22

# Verify the Node.js version:
node -v # Should print "v22.15.0".
nvm current # Should print "v22.15.0".

# Verify npm version:
npm -v # Should print "10.9.2".

mkdir demo
cd demo

1. Basic Node.js HTTP Server (Express.js)

Create server.js file under demo folder

// server.js
const express = require('express');
const app = express();
const PORT = 3000;

app.get('/', (req, res) => {
  res.send('Hello from Node.js backend! 🚀');
});

app.listen(PORT, () => {
  console.log(`Server running at http://localhost:${PORT}`);
});

How to Run:

1. Install Express

    npm init -y
    npm install express
   

2. Start the server:

    node server.js
   

3. Test it:

   • Open http://<PUBLIC_IP>:3000 in a browser.

   • You should see: Hello from Node.js backend! 🚀

4. PM2 (Production Process Manager)

   For running Node.js in the background (useful for production):

    npm install pm2 -g
    pm2 start server.js
    pm2 save
    pm2 startup  # Auto-start on server reboot
   

pm2 stop server.js

Key PM2 Commands:

pm2 start server.js

Go to godaddy dns management section and map public ip of ubuntu server with the domain name

Edit A Record and CNAME record

Step 1: Install NGINX

sudo apt update
sudo apt install nginx -y
sudo systemctl start nginx
sudo systemctl enable nginx

Verify NGINX is running:

systemctl status nginx

(Should see active (running))

Step 2: Configure NGINX as a Reverse Proxy

Edit the default NGINX config or create a new one:

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

Basic Reverse Proxy Example

Replace yourdomain.com with your actual domain and backend server.

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

    location / {
        proxy_pass http://localhost:3000;  # Your backend server
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_cache_bypass $http_upgrade;
    }
}

HTTPS with Let’s Encrypt

sudo apt install certbot python3-certbot-nginx -y
sudo certbot --nginx -d yourdomain.com -d www.yourdomain.com

(Follow prompts to enable HTTPS.)

---

Step 3: Enable the Configuration

1. Link the config file:

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

2. Test NGINX config:

    sudo nginx -t
   

   (Should say syntax is OK.)

3. Restart NGINX:

    sudo systemctl restart nginx
   

---

Step 4: Verify the Reverse Proxy

1. Access your domain https://yourdomain.comor https://www.yourdomain.com in a browser.

2. Check NGINX logs for errors:

    sudo tail -f /var/log/nginx/error.log
   

   Advanced Example (With Routes & Middleware)

   edit server.js

    const express = require('express');
    const app = express();
    const PORT = 3000;
   
    // Middleware (Parse JSON requests)
    app.use(express.json());
   
    // Routes
    app.get('/', (req, res) => {
      res.send('Home Page');
    });
   
    app.get('/api', (req, res) => {
      res.json({ message: 'API Response', status: 200 });
    });
   
    app.post('/api/login', (req, res) => {
      const { username, password } = req.body;
      res.json({ user: username, auth: true });
    });
   
    // Start Server
    app.listen(PORT, () => {
      console.log(`Node.js server running on http://localhost:${PORT}`);
    });
   

    pm2 stop server.js
    pm2 start server.js
   

3. Test with curl:

    curl http://<public-ip>:3000
    # Output: "Home Page"
   
    curl http://<public-ip>:3000/api
    # Output: {"message":"API Response","status":200}
   
    curl -X POST -H "Content-Type: application/json" -d '{"username":"admin","password":"123"}' http://<public-ip>:3000/api/login
    # Output: {"user":"admin","auth":true}