Two thing that should be plug-able in tempest if we want to keep it independent from many custom scenario related thing. https://github.com/openstack/tempest/blob/master/tempest/common/utils/linux/remote_client.py https://github.com/openstack/tempest/blob/master/tempest/scenario/test_network_basic_ops.py#L43 Certain instance operations for - asking the VM to validate the correct flavor applied - asking the VM to make connection to another VM or external service - asking the VM to write to a volume - asking the VM to ... Custom cinder/nova scheduler related verification capability.