Minimal pure node js server

server.js

const http = require('http');
const url = require('url');

function handler(req, res) {
   res.writeHead(200, {'Content-type':'text/plain'});
    res.write('Hello, I am a webserver !');
    res.end();
}

const port = process.env.PORT || 8080;  
console.log('Server listening on http://localhost:'+port);
const server = http.createServer(handler);
server.listen(port);