Cannot connect behind ELB

[gordyr]

Hi,

I'm having some real troubles getting this set up.

I need to run a cluster of node.js instances, all running primus (https://github.com/primus/primus) with the sock.js transport from behind an ELB.

My ELP listeners are configures like so:

TCP 80 -> TCP 80 HTTPS 8084 -> HTTPS 8084

8084 is the port that the node.js/Primus servers use. When a client connects a simple GET request is sent to the node js server, I intercept it and enable CORS since it is on a different domain to my app then finally Primus/Sock.js should upgrade the connection to a websocket through port 80.

I have correctly enabled the proxy protocol for both ports 8084 and 80 and of course have installed proxywrap.

Now everything works perfectly when I set the primus connection address to a single server and disable proxywrap. But as soon as I turn proxywrap back on and try to send connect to the loadbalancer, it fails.

I'm relatively inexperienced with this kind of stuff and feel at a complete loss.

Any help or advice you could give me would be greatly appreciated.

Here is my node.js/Primus code:

var Primus = require('primus');
var https = require('https');
var proxiedHttps = require('proxywrap').proxy(https);
var fs = require('fs');

var options = {
        key: fs.readFileSync('/key.key'),
        cert: fs.readFileSync('/cert.crt'),
        ca: fs.readFileSync('/csa.csa'),
        requestCert: true,
        rejectUnauthorized: false
};

//Create server and allow cross domain
var server = proxiedHttps.createServer(options, function(request, response){    
        var origin = (request.headers.origin || "*");
        if (request.method.toUpperCase() === "OPTIONS"){
            response.writeHead("204", "No Content", {
                            "access-control-allow-origin": origin,
                            "access-control-allow-methods": "GET, POST, PUT, DELETE, OPTIONS",
                            "access-control-allow-headers": "content-type, accept",
                            "access-control-max-age": 10, // Seconds.
                            "content-length": 0
            });

            return( response.end() );
        }

        var requestBodyBuffer = [];
        request.on("data", function( chunk ){
                requestBodyBuffer.push( chunk );
        });     
        request.on("end", function(){
                var requestBody = requestBodyBuffer.join( "" );
                var responseBody = (
                    "Thank You For The Cross-Domain AJAX Request:\n\n" +
                    "Method: " + request.method + "\n\n" +
                    requestBody
                );
                response.writeHead("200", "OK", {
                                    "access-control-allow-origin": origin,
                                    "content-type": "text/plain",
                                    "content-length": responseBody.length
                });

                return( response.end( responseBody ) );
            }
        );
});

[daguej]

Your ELB should use TCP for port 8084 as well. In HTTPS mode, the ELB actually decrypts traffic and fiddles with the application-later protocol (HTTP in this case), which we don't want.

[gordyr]

Thanks.. I've just tried as you suggested and used require('net') instead of require('https') (which I assume is correct) but the problem still remains.

[daguej]

You should still use the https module in node, but the ELB needs to be set to TCP mode instead of HTTPS.