ceph: allow overriding cluster CR name in helm chart

The cluster CR name defaults to the namespace where the CR is created.
This name may need to be overridden if the chart is taking over a
cluster that had been previously created with a different name.

Signed-off-by: Travis Nielsen <tnielsen@redhat.com>

cluster/charts/rook-ceph-cluster/templates/cephcluster.yaml

@@ -2,7 +2,7 @@
 apiVersion: ceph.rook.io/v1
 kind: CephCluster
 metadata:
-  name: {{ .Release.Namespace }}
+  name: {{ default .Release.Namespace .Values.clusterName }}
 spec:
   monitoring:
     rulesNamespace: {{ default .Release.Namespace .Values.monitoring.rulesNamespaceOverride }}

cluster/charts/rook-ceph-cluster/values.yaml

@@ -5,6 +5,9 @@
 # Namespace of the main rook operator
 operatorNamespace: rook-ceph
 
+# The metadata.name of the CephCluster CR. The default name is the same as the namespace.
+#clusterName: rook-ceph
+
 # Ability to override ceph.conf
 configOverride:
 #configOverride: |