Creates an Openstack machine, from an already globally defined cloud name and template without registering it as a Jenkins agent.
This step has a third optional String parameter named scope specifying how long is the server expected to live:

run

The booted machine will be kept alive whilst the current run is kicking. This is the default mode if no scope is defined.

unlimited

The booted machine will be kept alive forever. Mind the possible resources extarvation at the Openstack provider!