Safely shutdown each part

As the services are brought up, I think we need a way to shut them down individually or a way to shut down all the ones that were successful coming up.

I have run into the case (while testing something else) that Kafka failed to come up properly. It would be helpful to be able to shutdown everything that came up before it safely rather than individually going to each node or running a killall kind of thing.

Perhaps the way to do this would be as they successfully come up, we add the shutdown sequence to a script on the master node. Then we can just call that script. (perhaps just magpie-cleanup and magpie-post-run but run as a new job?)

Start by reading the magpie-cleanup and magpie-post-run entry points and tracing how services are started on the master node. Check how Kafka startup failures are handled and how shutdown currently targets individual nodes. Done means the relevant successful services can be safely shut down together or individually after a partial startup.