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0.0. The What

Node.js is an open-source, cross-platform JavaScript runtime environment that allows developers to run JavaScript on the server side.

As a system administrator, we may not write Node.js applications daily, but we might encounter it in various scenarios—whether it's running a web app, managing microservices, or troubleshooting performance issues.

0.1. Environment

I used Debian and Ubuntu server editions, namely Debian 11 & 12, Ubuntu 22.04 & 24.04 LTS Servers.

0.2. Sources

• ChatGPT
• Node.js
• Npm.js
• Deepseek

There might be a lot of installation options but I'd like to concentrate on 2 of them.

1.1. Install Debian (Ubuntu) Packages - System wide

Installing the default packages of the distribution. Packages may be (actually definitely) old. So you will have old (but stable) Node.js. It can be used by all the users. Ideal for running a production site.

Update repositories

sudo apt update

Install Node.js and NPM (Node Package Manager)

sudo apt install -y nodejs npm

Verify the Node.js and Npm versions:

node -v 
npm -v 

1.2. Install With NVM (Node Version Manager) - User based

Downloading and installing the latest stable package. Only your user will be able to use Node.js, still stable but of course not as stable as the Debian package. Ideal for testing or developing purposes.

Install curl (Debian 12 doesn't have it by default)

sudo apt update
sudo apt install -y curl

Download and install nvm (node version manager):

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.2/install.sh | bash

Either restart the shell or run:

\. "$HOME/.nvm/nvm.sh"

Download and install latest stable Node.js:

nvm install 22

Verify the Node.js version:

node -v 

See the active Node.js version

nvm current 

Verify NPM (Node Package Manager) version:

npm -v 

Nvm allows installing more than 1 versions of node.js. Lets install version 23 (non LTS)

nvm install 23

See current active version

nvm current

Change to version 22

nvm use 22

List installed versions

nvm ls

Set 22 as the default version

nvm alias default 22

Remove version 23

nvm uninstall 23

2.1. Running Javascript Programs

Let's write a simple JavaScript program:

nano hello.js

Fill as below:

console.log("Hello from Node.js!");

Run it:

node hello.js

Let's write another one:

nano time.js

Fill as below:

const now = new Date();
console.log(`Time now is: ${now.toLocaleString()}`);

Run it:

node time.js

2.2. Installing/Running Packages

You can install/run packages from https://www.npmjs.org/

Run a package without permanently installing. It asks to install, you can say Y.

npm exec cowsay "Hello world"

Install a package locally, we'll use it in a script

npm install chalk@4

Saved to ./node_modules/

Let's use it in a script

nano chalktest.js

Fill as below:

const chalk = require('chalk');
console.log(chalk.green('Hello from Node.js!'));

Run it:

node chalktest.js

Update installed packages:

npm update

List locally installed packages:

npm list

If you want to uninstall a package:

npm uninstall chalk