This feature is to enable remote java web application debugging. It has been tested and verified. A wiki page has been created to show how to use the feature.
enable java debugging
added readme file for enabling java debugging
I examined the pull request. While implementation is simple, it cannot serve the need of various clouds we offer (open source, Micro Cloud Foundry, CloudFoundry.com, and other clouds hosted by partners). For example, you are expecting clients to specify the debug port through an env variable. How does a developer know which ports are free (realize that he may be deploying to a machine other than local and there may be many applications running on the same box)? This will force developers to keep trying (stop, add-env, start cycle) until a free port is found. Second, the user experience is not as good as we will like (official implementation requires just passing '-d' to 'vmc push'). Third, there is no ability to reject debugging per cloud installation basis. For example, we do not want users to debug (production) applications on cloudfoundry.com (and even if your pull request is accepted, won't work due to how ports are opened etc., this consuming a port for no benefit).
Take a look at official implementation. It may look complex (you comment earlier), but because it addresses all issue I raise above.
As I mentioned earlier, extending the official debugging support to other languages (one of your earlier questions) is far more useful than re-doing Java debugging.
Thanks for your comments. I knew there must be some reason that you made more sophisticated changes. We had similar idea initially as yours, later, we decided to go with simple one. You are right, the port availability is the major issue in my implementation if we consider all-around cases.