Proxy a node server and websocket server under same subdomain with node-http-proxy

Question

This is my proxy setup:

var express = require('express');
var vhost   = require('vhost');
var proxy   = require('http-proxy').createProxyServer();

var app = express();
var server = http.createServer(app);

// route api subdomain to port 2000
app.use(vhost('api.*.*', function(req, res) {
  proxy.web(req, res, {target: 'http://localhost:2000'});
}));

// I need to get websocket requests to ws://api.example.com proxied port 4000
server.on('upgrade', function(req, socket, head) {
  // proxy.ws seems like the right way to go, but how do I get this under the vhost?
  proxy.ws(req, socket, head);
});

// everything else goes to port 3000
app.get('*', function(req, res) {
  proxy.web(req, res, {target: 'http://localhost:3000'});
});

server.listen(80, function() {
  console.log('Proxy listening on port 80.');
});

Do I need to dive into the req, res objects inside the vhost handler to route the socket request? What is the right approach?

Update

Not pretty, but I'm going to give this a try.

server.on('upgrade', function(req, socket, head) {
  var host = req.headers.host;
  var parts = host.split('.');
  if (parts.length === 3 && parts[0] === 'api') {
    proxy.ws(req, socket, head, {target: {target: 'http://localhost:2000'});
  }
});

Hopeful for a more elegant vhost-like solution.

Answer 1

It turns out to be as simple as this:

server.on('upgrade', vhost('api.*.*', function(req, socket, head) {
  proxy.ws(req, socket, head);
}));

vhost can be wrapped around the upgrade listener just like it can be used as middleware for http requests.