Support cinder backups to specific ceph cluster

New CinderBackupRbdClusterName and CinderBackupRbdClientUserName
parameters support configuring the cinder-backup service to store
backups on an external ceph cluster defined by CephExternalMultiConfig.

The new parameters default to an empty string, in which case the default
CephClusterName and CephClientUserName values are used.

Change-Id: I0aa4108c029cbb9b8d88a5f87b1ea517bb54059e

deployment/cinder/cinder-backup-container-puppet.yaml

@@ -56,6 +56,16 @@ parameters:
     type: string
     constraints:
     - allowed_values: ['swift', 'ceph', 'nfs', 'gcs', 's3']
+  CinderBackupRbdClusterName:
+    type: string
+    default: ''
+    description: The Ceph cluster where backups are to be stored. If no value
+                 is specified then the CephClusterName value is used.
+  CinderBackupRbdClientUserName:
+    default: ''
+    type: string
+    description: The Ceph client name used by the backup service. If no value
+                 is specified then the CephClientUserName value is used.
   CinderBackupRbdPoolName:
     default: backups
     type: string
@@ -135,14 +145,25 @@ outputs:
           - get_attr: [CinderBase, role_data, config_settings]
           - if:
             - {equals: [{get_param: CinderBackupBackend}, 'ceph']}
-            - cinder::backup::ceph::backup_ceph_user: {get_param: CephClientUserName}
+            - cinder::backup::ceph::backup_ceph_user:
+                str_replace:
+                  template: USERNAME
+                  params:
+                    USERNAME:
+                      if:
+                        - {equals: [{get_param: CinderBackupRbdClientUserName}, '']}
+                        - {get_param: CephClientUserName}
+                        - {get_param: CinderBackupRbdClientUserName}
               cinder::backup::ceph::backup_ceph_pool: {get_param: CinderBackupRbdPoolName}
               cinder::backup::ceph::backup_ceph_conf:
-                list_join:
-                - ''
-                - - '/etc/ceph/'
-                  - {get_param: CephClusterName}
-                  - '.conf'
+                str_replace:
+                  template: /etc/ceph/CLUSTER.conf
+                  params:
+                    CLUSTER:
+                      if:
+                        - {equals: [{get_param: CinderBackupRbdClusterName}, '']}
+                        - {get_param: CephClusterName}
+                        - {get_param: CinderBackupRbdClusterName}
           - if:
             - {equals: [{get_param: CinderBackupBackend}, 'swift']}
             - cinder::backup::swift::backup_swift_container: volumebackups

releasenotes/notes/cinder-backup-other-ceph-cluster-36852bf2edfd11a7.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    The cinder-backup service can be configured to store backups on external
+    Ceph clusters defined by the ``CephExternalMultiConfig`` parameter. New
+    ``CinderBackupRbdClusterName`` and ``CinderBackupRbdClientUserName``
+    parameters can be specified, which override the default ``CephClusterName``
+    and ``CephClientUserName`` values respectively.