well, getting it all running took me a couple of days and a lot of research. Maybe it is related to my setup because I wanted the nodes to run on a windows server and have vboxwebsrv run as a scheduled task (so it gets fired up when the server is rebooted). As far as I get it, one has to:
- Create the node in Jenkins first (otherwise the java web start stuff later on won't work).
- Then manually (i.e. with GUI) launch the virtual box instance on the windows server
- In that instance go to jenkins webpage and then somewhere (forgot where) click on that link to get the java web start stuff installed within the virtual box.
- then shutdown the virtual machine and create the scheduled task to start vboxwebsrv
One fun part is that when vboxwebsrv is started as a scheduled task, one will not see the UI at all (because it as run under the service account). So before setting up the scheduled task, one first has to get the JAVA web start up and running. Also, non of the other start up methods seemed to be able to connect from Jenkins to virtual box correctly! I always got the node to fire up the virtual box but never to actually start the build. I believe there were also problems as the scheduled task runs under the service account and therefore cannot access the usually virtualbox configuration folder (I remember something about having to create a virtual link). Also there seems to be no proper console output if the node is running in headless mode. Speaking of which, I did not find a proper explanation what the specific start up modes do. Plus there were some refresh issues where the vboxwebsrv was correctly detected but there were no machines in the list below it to select. I first had to save it without setting anything, then go back to the page and there the machine was suddenly listed.
All in all, it was extremely difficult and frustrating! Granted, I haven't really done much with Jenkins before, but getting everything except for the virtualbox-plugin running was pretty easy. I hope to someday find the time to re-create all the steps at home and write a step-by-step guide and post it in my personal blog. But at my company, everything is working right now so I unfortunately don't have time to de-install everything just for the purpose of documentation.