node.js: proxy websockets to other port

Question

I have written http proxy in node.js running on port 80. All I need is to redirect socket.io traffic to port 9090 and standard http traffic to Apache on 8080. This is my proxy code:

httpProxy = require('http-proxy');

httpProxy.createServer(function (req, res, proxy) {
    if (req.url.match(/socket.io/)) {
        proxy.proxyRequest(req, res, {
            host: 'localhost',
            port: 9090
        });
    } else {
        proxy.proxyRequest(req, res, {
            host: 'localhost',
            port: 8080
        });
    }
}).listen(80);

Everything works, but io.socket falls back to xhr-polling.

http://localhost/client.htm    - falls back to xhr-polling

file:///C:/.../client9090.htm  - still uses websocket

socket.io app is running on port 9090, client.htm connects to 80 and client9090.htm connects directly to 9090.

It looks like a node-http-proxy makes socket.io app to work in xhr-polling mode. Client is Chrome v.25

socket.io app code

var io = require('socket.io').listen(9090);

io.on('connection', function (socket) {

        socket.on('hi!', function (data) {
            console.log(data);
            socket.emit('news');
        });

        socket.on('ahoj', function (data) {
            console.log(data);
        });
    });

client.htm code

<script src="http://localhost/socket.io/socket.io.js"></script>
<script>
    var chat = io.connect('http://localhost')

    chat.on('connect', function () {
        chat.emit('hi!');
    });

    chat.on('news', function () {
        chat.emit('ahoj',{a:1,b:2});
    });
</script>

client9090.htm is the same but localhost is replaced by localhost:9090

As I said, everythig works well, only problem is, that node-http-proxy makes to fall back from websockets to xhr-polling. Can anyone help?

Answer 1

According to https://npmjs.org/package/http-proxy, when adding a callback to the httpProxy.createServer(), you have to manually proxy 'upgrade' events, so something like this:

httpProxy = require('http-proxy');

// added `var server =` here
var server = httpProxy.createServer(function (req, res, proxy) {
    if (req.url.match(/socket.io/)) {
        proxy.proxyRequest(req, res, {
            host: 'localhost',
            port: 9090
        });
    } else {
        proxy.proxyRequest(req, res, {
            host: 'localhost',
            port: 8080
        });
    }
}).listen(80);

// added upgrade listener section here:
server.on('upgrade', function (req, socket, head) {
    server.proxy.proxyWebSocketRequest(req, socket, head);
});

However, for the usage you described above, you don't even need the callback function - you could just as easily do something like this:

httpProxy = require('http-proxy');

var options = {
  pathnameOnly: true,
  router: {
    '/wiki': '127.0.0.1:8001',
    '/blog': '127.0.0.1:8002',
    '/api':  '127.0.0.1:8003'
  }
}

var proxyServer = httpProxy.createServer(options);
proxyServer.listen(80);