Configuring NodeJs App to Domain with NGINX Reverse Proxy

Reverse proxy is the recommended way to let your audience access your nodejs app. Never expose the application ports directly to the end users. Also, use a firewall like UFW to block all ports except 80 (http), 443 (https) and your SSH port with limited access.

Creating NodeJs Hello World App

Skip this step if you have already a running app.

Create your app directory.

mkdir helloworld
cd helloword

Init npm and Install Express. Leave all the options as default on npm init prompts.

npm init
npm install express --save

Create the index.js file and put the below sample content (/helloword/index.js)

var express = require('express');
var app = express();
app.get('/', function (req, res) {
  res.send('Hello World!');
});
app.listen(3001, function () {
  console.log('Hello app listening on port 3001!');
});

Now run the app

node index.js

Check your app is accessible in localhost in the specified port. For Example: 3001

You can check it using curl in the console.

curl http://localhost:3001 

Configure DNS

Add A record in your DNS Hosting Manager (Access your Domain Control Panel or DNS Hosting account like Cloudflare) For example :

A example.com 14400

Configure Nginx

Create a server block, replace example.com with your domain

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

Add the below content by replacing the example.com with your domain and update the port address to match your application port address.

server {
    listen 80;
    listen [::]:80;

    server_name example.com;
        
    location / {
        proxy_pass http://localhost:3001;
        include proxy_params;
    }
}

Enable the site in Nginx

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

Test the Nginx server blocks configuration

sudo nginx -t

If you see the following message, the syntax is correct

nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

Now restart the nginx service

sudo systemctl restart nginx

Now you can access your website on the Browser and see the output

Hello World!