Hello world in NodeJS and Express

This example can be used to dockerize or to play around with NodeJS and Express.
Prerequisites:

mkdir node-helloworld
cd Desktop/node-helloworld

index.js contents:

var express = require('express');
var app = express();

app.get('/', function(req, res) {
  res.send('Hello World!');
});

var server = app.listen(3000, function() {
  var host = server.address().address;
  var port = server.address().port;

  console.log('Example app listening at http://%s:%s', host, port);
});

package.json contents:

{
  "name": "myhelloworld",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node index.js"
  },
  "engines": {
    "node": "^v12.21.0"
  },
  "dependencies": {
    "express": "^4.17.1"
  }
}

Run:

npm install
npm start

To test - navigate to http://localhost:3000