Description of problem:
Cinder fails to connect to an internal Ceph cluster with customize name. At first try cinder-volume logs show the messages:

2018-10-01 19:53:06.141 60 ERROR cinder.volume.drivers.rbd [req-f7b133c8-f050-45e5-9bd9-a5d0f19d956f - - - - -] Error connecting to ceph cluster.: OSError: [errno 95] error connecting to the cluster
2018-10-01 19:53:06.141 60 ERROR cinder.volume.drivers.rbd Traceback (most recent call last):
2018-10-01 19:53:06.141 60 ERROR cinder.volume.drivers.rbd   File "/usr/lib/python2.7/site-packages/cinder/volume/drivers/rbd.py", line 349, in _do_conn
2018-10-01 19:53:06.141 60 ERROR cinder.volume.drivers.rbd     client.connect()
2018-10-01 19:53:06.141 60 ERROR cinder.volume.drivers.rbd   File "rados.pyx", line 886, in rados.Rados.connect (/builddir/build/BUILD/ceph-12.2.5/build/src/pybind/rados/pyrex/rados.c:9784)
2018-10-01 19:53:06.141 60 ERROR cinder.volume.drivers.rbd OSError: [errno 95] error connecting to the cluster
2018-10-01 19:53:06.141 60 ERROR cinder.volume.drivers.rbd

As an account of it, cinder is not functional at all, though Glance and Nova are working fine with the same cluster and the cluster itself is healthy.

The Ceph directory on the container is:
# docker exec -it openstack-cinder-volume-docker-0 ls /etc/ceph
CephSite1.client.admin.keyring      CephSite1.mgr.controller-0.keyring
CephSite1.client.manila.keyring     CephSite1.mgr.controller-1.keyring
CephSite1.client.openstack.keyring  CephSite1.mgr.controller-2.keyring
CephSite1.client.radosgw.keyring    CephSite1.mon.keyring
CephSite1.conf                      rbdmap

The backend configuration in cinder.conf is

[tripleo_ceph]
backend_host=hostgroup
volume_backend_name=tripleo_ceph
volume_driver=cinder.volume.drivers.rbd.RBDDriver
rbd_ceph_conf=/etc/ceph/CephSite1.conf
rbd_user=openstack
rbd_pool=volumes
rbd_secret_uuid=<secret key>

Version-Release number of selected component (if applicable):
rhosp14/openstack-cinder-volume:2018-09-26.1
$ docker exec -it mistral_executor rpm -qa | grep ceph
ceph-ansible-3.1.5-1.el7cp.noarch

How reproducible:


Steps to Reproduce:
1. Deploy a ceph cluster with customized name
parameter_defaults:
    CephClusterName: CephSite1
2. create a volume


Actual results:
Cinder fails to connect to the Ceph cluster using the rbd driver

Expected results:
Cinder connects to the Ceph cluster with RBD driver with the given parameters from tripleo

Additional info: