Question

Is it possible to get client’s hostname in Node / Express?

Something similiar to req.connection.remoteAddress which is used to obtain client’s IP.

Answer 1

Here’s a example:

var http = require('http'),
    dns  = require('dns');

http.createServer(function (req, res) {
  var ip = req.connection.remoteAddress;

  res.writeHead(200, {'Content-Type': 'text/html'});
  dns.reverse(ip, function(err, hostnames) {
    res.write("Ip: " + ip + "<br />");
    res.end("Your hostname(s) are " + hostnames.join("; "));
  });
}).listen(1337, '127.0.0.1');
console.log('Server running at http://127.0.0.1:1337/');

Read more on the official Node.js documentation website:
http://nodejs.org/docs/v0.6.18/api/dns.html#dns_dns_reverse_ip_callback