Within our internal build landscape, I need a proxy to deploy to the CF instance.
Even though I configured a proxy via environment variables, the CF client does not pick up the proxy configuration. It looks like one has to set it explicitly.

For my internal deployment, I am using this change:
https://github.com/jenkinsci/cloudfoundry/pull/2

I have created the pull request if you want to use it. There are other alternatives, of course