Set Up an Nginx Reverse Proxy

Step 1

Install Nginx

Install the distribution package and verify the service state.

sudo apt update
sudo apt install nginx
sudo systemctl status nginx --no-pager

Step 2

Create a server block

Replace example.com and port 3000. Preserve client address and protocol headers for the application.

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://127.0.0.1:3000;
        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;
    }
}

Step 3

Enable and validate the site

Enable the file according to your distribution layout, remove conflicting default configuration if appropriate, and test syntax before reload.

sudo nginx -t
sudo systemctl reload nginx

Step 4

Allow web traffic

Open only HTTP and HTTPS in the firewall. The backend port can remain private when Nginx is the only public entry point.

sudo ufw allow 'Nginx Full'

Step 5

Add HTTPS

After DNS resolves correctly, use a supported ACME client and follow its current official instructions. Confirm automatic renewal and test it without waiting for expiration.