http-server.js

const http = require('http');

let server = http.createServer();

server.on('request', (request, response) => {
  let {method, url, headers} = request;
  console.log(`Received ${method} request for "${url}".`);

  for (let headerName of Object.keys(headers)) {
    let headerValue = headers[headerName];
    console.log(`  ${headerName}: ${headerValue}`);
  }

  let bytesReceived = 0;
  request.on('data', (chunk) => {
    bytesReceived += chunk.length;
    console.log(`Received ${chunk.length} bytes of the request body.`);
  });

  request.on('end', () => {
    console.log(`Request has completed. Sending response.`);
    response.setHeader('Content-Type', 'text/plain');
    response.write(`Thank you for your ${method} request for "${url}".\n`);
    if (bytesReceived === 0) {
      response.write(`There was no request body.\n`);
    } else {
      response.write(`Received request body of size ${bytesReceived} bytes.\n`);
    }
    response.end();
  });

  request.on('error', (error) => {
    console.log(`There was an error receiving the request.`);
    console.error(error.stack);
  });
});

server.on('listening', () => {
  let {port} = server.address();
  console.log(`HTTP server listening on port ${port} ...`);
});

server.listen(5100);