How to get the correct IP address of a client into a Node socket.io app hosted on Heroku?

Question

I recently hosted my first Node app using Express and socket.io on Heroku and need to find the client's IP address. So far I've tried socket.manager.handshaken[socket.id].address, socket.handshake.address and socket.connection.address , neither of which give the correct address.

App: http://nes-chat.herokuapp.com/ (also contains a link to GitHub repo)

To view IPs of connected users: http://nes-chat.herokuapp.com/users

Anyone know what the problem is?

Answer 1

You can do it in one line.

function getClientIp(req) {
    // The X-Forwarded-For request header helps you identify the IP address of a client when you use HTTP/HTTPS load balancer.
    // http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/TerminologyandKeyConcepts.html#x-forwarded-for
    // If the value were "client, proxy1, proxy2" you would receive the array ["client", "proxy1", "proxy2"]
    // http://expressjs.com/4x/api.html#req.ips
    var ip = req.headers['x-forwarded-for'] ? req.headers['x-forwarded-for'].split(',')[0] : req.connection.remoteAddress;
    console.log('IP: ', ip);
}

I like to add this to middleware and attach the IP to the request as my own custom object.

Answer 2

The client IP address is passed in the X-Forwarded-For HTTP header. I haven't tested, but it looks like socket.io already takes this into account when determining the client IP.

You should also be able to just grab it yourself, here's a guide:

function getClientIp(req) {
  var ipAddress;
  // Amazon EC2 / Heroku workaround to get real client IP
  var forwardedIpsStr = req.header('x-forwarded-for'); 
  if (forwardedIpsStr) {
    // 'x-forwarded-for' header may return multiple IP addresses in
    // the format: "client IP, proxy 1 IP, proxy 2 IP" so take the
    // the first one
    var forwardedIps = forwardedIpsStr.split(',');
    ipAddress = forwardedIps[0];
  }
  if (!ipAddress) {
    // Ensure getting client IP address still works in
    // development environment
    ipAddress = req.connection.remoteAddress;
  }
  return ipAddress;
};

Answer 3

The below worked for me.

Var client = require('socket.io').listen(8080).sockets;

client.on('connection',function(socket){ 
var clientIpAddress= socket.request.socket.remoteAddress;
});