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How to Setup a Koa.js Node Application on Ubuntu 20.04 with Nginx

Node.jsWeb ServersUbuntu
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Updated on November 21, 2023
How to Setup a Koa.js Node Application on Ubuntu 20.04 with Nginx header image

Overview

Koa.js is a modern web framework built on Node.js. It allows developers to build high-performace and scalable web applications by focusing on a concise and extendible API built on asynchronous functionality in Node.js.

Prerequisites

Install Nodejs & Yarn

Koa requires Node.js version v7.6.0 or higher.

  1. Install the latest LTS version of Nodejs.

     $ curl -fsSL https://deb.nodesource.com/setup_lts.x | sudo -E bash -
 $ sudo apt-get install nodejs

  2. Verify successful Nodejs installation.

     $ node -v
 v16.xx.x

  3. Install Yarn.

     $ curl -fsSL https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
 $ echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
 $ sudo apt-get update && sudo apt-get install yarn

  4. Verify successful Yarn installation.

     $ yarn -v
 1.2x.xx

Setup Application

  1. Create the project root directory.

     $ cd ~
 $ mkdir koaserver && cd koaserver

  2. Initialize the Node.js project environment through yarn and answer the question prompts according to your project.

     $ yarn init

  3. Install Koa.

     $ yarn add koa

  4. Create index.js.

     $ touch index.js

  5. Add sample code to index.js.

     const Koa = require("koa");
 const app = new Koa();

 app.use(async (ctx) => {
         ctx.body = "Hello World";
 })

 app.listen(3000);

Setup PM2

PM2 will manage the Node.js application to run in the background as a system process. PM2 will automatically restart the server if it crashes, handle logs, and monitor performance.

  1. Install PM2.

     $ sudo yarn global add pm2

  2. Confirm successful installation.

     $ pm2 -V
 5.x.x

  3. Navigate to the project folder and start the Koa server through PM2.

     $ cd ~/koaserver
 $ pm2 start index.js --name koaserver

  4. Set PM2 to run on startup.

     $ eval "$(pm2 startup | tail -1)"

  5. Save PM2 configuration.

     $ pm2 save

Setup Reverse Proxy through Nginx

  1. Install Nginx.

     $ sudo apt-get install nginx

  2. Delete default Nginx server block.

     $ sudo rm /etc/nginx/sites-enabled/default

  3. Create a new Nginx server block.

     $ sudo touch /etc/nginx/sites-enabled/koaserver.conf

  4. Add the following text to the file.

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

     server_name _;

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

  5. Restart Nginx.

     $ sudo systemctl nginx restart

  6. Verify a working server response by navigating to your server's IP address in a browser. You should see a Hello World message.

Setup Firewall

For added security, configure a firewall to restrict access to internal service ports.

  1. Setup UFW rules.

     $ sudo ufw allow 22,80,443/tcp

Add any other ports according to your application and needs.

  1. Enable UFW.

     $ sudo ufw enable

  2. Verify UFW working.

     $ sudo ufw status
 Status: active

Conclusion

For more information, refer to the official Koa.js documentation.