VMware:1-1 mapping between nova-compute service instance and vsphere cluster

Feature Lead: Andrey Danin
Design Reviewer: Andrey Danin
Developers: Igor Zinovik
QA: Tatiana Dubyk

Currently there is 1-N mapping between nova-compute service and vSphere cluster
(cluster that is formed from ESXi hosts by vCenter server). Single nova-compute
service instance uses many vSphere clusters managed by single vCenter. We can
change this behaviour to 1-1 mapping, so that single nova-compute service
instances interacts with single vSphere cluster. We also want in scope of this
blueprint add functionality that will allow user to add vSphere clusters to
deployed Mirantis OpenStack environment with vCenter as hypervisor option.

This change will act as intermediate step to implement things like
fine-grained resource allocation, support of multiple vCenter servers and
heterogeneous OpenStack cloud (a cloud that simultaneously runs on top of
multiple hypervisors, e.g. KVM and vCenter).