Nginx as a Reverse Proxy

What is Nginx?

Nginx (engine-x) is a web server commonly used as a reverse proxy, load balancer, and static HTTP server.

In this pipeline it sits between users and your Node app:

User → Nginx (80/443) → Node App (3000) → Nginx → User

Users never need :3000 in the URL.

Why Use It?

• Hide internal ports
• Clean URLs (https://your-domain.com)
• Better security and traffic handling
• Easy path to HTTPS (next lesson)

Install Nginx

sudo apt update
sudo apt install nginx

Configure Reverse Proxy

Edit the site config (Ubuntu default):

sudo vim /etc/nginx/sites-available/default

Example server block:

server {
    listen 80;
 
    server_name your-domain.com;
 
    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;
    }
}

Replace your-domain.com with your domain or EC2 public DNS while testing.

Quick Vim reminders

Restart Nginx and run the app

sudo systemctl restart nginx
pm2 start app.js   # or pm2 restart app

Now:

• App listens on localhost:3000
• Public traffic hits port 80 via Nginx

Final Flow

Browser Request
   ↓
Nginx (Port 80)
   ↓
Node App (Port 3000)
   ↓
Response back to user