Jetty - proxy server with dynamic registration

Question

We have a number of Jetty http(s) servers, all behind different firewalls. The http servers are at customer sites (not under our control). Opening ports in the firewalls at these sites is not an option. Right now, these servers only serve JSON documents in response to REST requests.

We have web clients that need to interact with a given http server based on URL parameter or header value.

This seems like a straightforward proxy server situation - except for the firewall.

The approach that I'm currently trying is this:

Have a centralized proxy server (also Jetty based) that listens for inbound registration requests from the remote http servers. The registration request will take the form of a Websocket connection, which will be kept alive as long at the remote HTTP server is available. On registration, the Proxy Server will capture the websocket connection and map it to a resource identifier.

The web client will connect the proxy server, and include the resource identifier in the URL or header.

The proxy server will determine the appropriate Websocket to use, then pass the request on to the HTTP server. So the request and response will travel over the Websocket. Once the response is received, it will be returned to the web client.

So this is all well and good in theory - what I'm trying to figure out is:

a) is there a better way to achieve this?

b) What's the best way to set up Jetty to do the proxying on the HTTP Server end of the pipe?

I suppose that I could use Jetty's HttpClient, but what I really want to do is just pull the HTTP bytes from the websocket and pipe them directly into the Jetty connector. It doesn't seem to make sense to parse everything out. I suppose that I could open a regular socket connection on localhost, grab the bytes from the websocket, and do it that way - but it seems silly to route through the OS like that (I'm already operating inside the HTTP Server's Jetty environment).

It sure seems like this is the sort of problem that may have already been solved... Maybe by using a custom jetty Connection that works on WebSockets instead of TCP/IP sockets?

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Update: as I've been playing with this, it seems like another tricky problem is how to handle request/response behavior (and ideally support muxing over the websocket channel). One potential resource that I've found is the WAMP sub-protocol for websockets: http://wamp.ws/

Answer 1

In case anyone else is looking for an answer to this one - RESTEasy has a mocking framework that can be used to invoke the REST functionality without running through a full servlet container: http://docs.jboss.org/resteasy/docs/2.0.0.GA/userguide/html_single/index.html#RESTEasy_Server-side_Mock_Framework

This, combined with WAMP, appears to do what I'm looking for.