Description of problem:
A deployment of OSP with external Ceph cluster ended without errors. The deployment used puppet-ceph-external.yaml environment file:

resource_registry:
  OS::TripleO::CephClusterConfig::SoftwareConfig: ../puppet/extraconfig/ceph/ceph-external-config.yaml

parameter_defaults:
  # NOTE: These example parameters are required when using Ceph External
  CephClusterFSID: '<Cluster UID>'
  CephClientKey: '<yrabl-cinder UID>'
  CephExternalMonHost: '<monitor IP Address>'

  NovaEnableRbdBackend: true
  CinderEnableRbdBackend: true
  GlanceBackend: rbd

  NovaRbdPoolName: 'yrabl-nova'
  CinderRbdPoolName: 'yrabl-cinder'
  GlanceRbdPoolName: 'yrabl-glance'
  CephClientUserName: 'yrabl-cinder'

  # finally we disable the Cinder LVM backend
  CinderEnableIscsiBackend: false

After the deployment, the Glance configuration file shows the following store settings:
stores=glance.store.http.Store,glance.store.rbd.Store
default_store=rbd
rbd_store_chunk_size=8
rbd_store_pool=yrabl-cinder
rbd_store_user=openstack
rbd_store_ceph_conf=/etc/ceph/ceph.conf
rados_connect_timeout=0


Version-Release number of selected component (if applicable):
python-tripleoclient-0.1.1-2.el7ost.noarch
openstack-tripleo-puppet-elements-0.0.2-1.el7ost.noarch
openstack-tripleo-heat-templates-kilo-0.8.7-12.el7ost.noarch
openstack-tripleo-image-elements-0.9.7-2.el7ost.noarch
openstack-tripleo-heat-templates-0.8.7-12.el7ost.noarch
openstack-tripleo-0.0.7-1.el7ost.noarch
openstack-tripleo-common-0.1.1-1.el7ost.noarch

How reproducible:
100%

Steps to Reproduce:
1. Deploy OSP with OSPD with the following command
# openstack overcloud deploy --stack test01 --templates openstack-tripleo-heat-templates/ -e openstack-tripleo-heat-templates/environments/puppet-pacemaker.yaml -e openstack-tripleo-heat-templates/environments/storage-environment.yaml -e openstack-tripleo-heat-templates/environments/puppet-ceph-external.yaml --ntp-server clock.redhat.com --control-scale 3 --compute-scale 3
2. Create a new image

Actual results:
Glance fails to connect to the Ceph cluster - Glance cannot function with its default store

Expected results:
Glance functions properly, and sets with the user and pool that were configured in puppet-ceph-external.yaml