Olaf already mentioned gogo shell, some other ideas:
Perhaps you could check the logfile of the server? ssh + tail + grep should do the trick.
Or place a testinstance of the portlet on a page, fetch the page and parse for some string that tells you that the expected version is deployed (e.g. version or build number)
What we do:
Since most of our services have rest endpoints nowadays, we usually have a "Get Status" method and we call it from a script to check if the module is still working correctly.
