Support for using a pre-existing external Ceph Storage cluster with Overcloud deployments caused all deployments using a Tuskar plan to fail. This included deployments through the web UI and CLI when --plan is used instead of --templates. This was irrespective of whether any Ceph Storage nodes were deployed (external or otherwise). Failed deployments resulted in the following error:
ERROR: openstack ERROR: Property error : CephClusterConfig: ceph_storage_count The Parameter (Ceph-Storage-1::CephStorageCount) was not provided.
This fix modifies Tuskar so that it can work with nested references to the top level Heat templates scaling parameters (like CephStorageCount in this case). Deployments using Tuskar now function without encountering the CephStorageCount error.