Configuring Nginx as a Reverse Proxy on EC2 Routing Traffic to Node.js

Configuring Nginx as a Reverse Proxy on EC2

Nginx sits in front of your Node.js app and handles incoming HTTP requests. It routes traffic to the Node.js process running on port 3000, provides SSL termination, and supports WebSockets for Socket.io.

Why Use Nginx as a Reverse Proxy?

1. Port management Nginx on port 80/443, Node.js on port 3000 (no need to run Node as root)
2. SSL termination Nginx handles HTTPS, Node.js handles plain HTTP
3. Static files Nginx serves static files faster than Node.js
4. Load balancing Distribute traffic across multiple Node.js instances
5. WebSocket support Proxy WebSocket connections for Socket.io
6. Gzip compression Compress responses before sending to client

Step 1: Create the Nginx Configuration

sudo nano /etc/nginx/sites-available/devtinder

Add this configuration:

server {
    listen 80;
    server_name yourdomain.com;  # or your EC2 public IP

    # API routes
    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_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;
    }

    # Socket.io WebSocket support
    location /socket.io/ {
        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_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

Step 2: Enable the Configuration

# Create a symbolic link to sites-enabled
sudo ln -s /etc/nginx/sites-available/devtinder /etc/nginx/sites-enabled/

# Remove the default site
sudo rm /etc/nginx/sites-enabled/default

# Test the configuration
sudo nginx -t

You should see:

nginx: configuration file /etc/nginx/nginx.conf test is successful

Step 3: Restart Nginx

sudo systemctl restart nginx

Step 4: Verify

From your local machine:

curl http://your-ec2-public-ip/api/health

This should return your API response. Nginx is now proxying traffic to the Node.js app on port 3000.

Key Configuration Explained

proxy_pass Tells Nginx where to forward requests (the Node.js app on port 3000).

proxy_http_version 1.1 Uses HTTP/1.1 for the proxy connection, required for WebSockets.

Upgrade and Connection headers These are critical for WebSocket support. Without them, Socket.io won't work.

X-Real-IP and X-Forwarded-For Pass the client's real IP to Node.js. Without these, Node.js sees Nginx's IP (127.0.0.1) instead of the client's IP.

X-Forwarded-Proto Passes the original protocol (http or https) to Node.js. Useful for generating correct redirect URLs.

Gzip Compression

Add gzip compression to reduce response sizes:

server {
    # ... existing config ...

    gzip on;
    gzip_types text/plain application/json application/javascript text/css;
    gzip_min_length 1000;
}

Rate Limiting (Optional)

Protect your API from abuse:

limit_req_zone $binary_remote_addr zone=api:10m rate=10r/s;

server {
    location / {
        limit_req zone=api burst=20 nodelay;
        proxy_pass http://localhost:3000;
        # ... other settings ...
    }
}

This allows 10 requests per second with a burst of 20.

The Takeaway

Configuring Nginx as a reverse proxy involves creating a server block that listens on port 80, proxies requests to localhost:3000 (Node.js), and includes the Upgrade and Connection headers for WebSocket support. Enable the configuration with a symbolic link, test with nginx -t, and restart. The key headers (X-Real-IP, X-Forwarded-For, X-Forwarded-Proto) pass client information to the Node.js app.