validate cephfs name for deployed ceph

During overcloud deploy, if the cephfs filestystem
name is explicitly configured via new parameter introduced
in [1], we fail the deployement with exception.

The parameter is intended only for external ceph cluster.

[1] https://review.opendev.org/c/openstack/tripleo-heat-templates/+/904034

Change-Id: I4a909402cc9a0af5bd8c934fd4679678c67338f7

tripleoclient/utils.py

@@ -1140,6 +1140,29 @@ def check_ceph_fsid_matches_env_files(old_env, environment):
                                                       stack_ceph_fsid))
 
 
+def validate_cephfs_name(environment):
+    """ Validate cephfs filessystem name for internal ceph
+
+    When ceph is deployed internally, it is deployed with single default
+    filesystem named 'cephfs' always, where as it is configurable
+    only for external ceph.
+    For this reason, we need to validate if deployed ceph is configured
+    with the parameter and raise the expection.
+    """
+
+    cephfs_filesystem_name = environment.get(
+        'parameter_defaults', {}).get(
+            'ManilaCephFSFilesystemName')
+    if cephfs_filesystem_name and cephfs_filesystem_name != "cephfs":
+        ceph_deployed = environment.get(
+            'resource_registry', {}).get(
+                'OS::TripleO::Services::CephMon', 'OS::Heat::None')
+        if (ceph_deployed != "OS::Heat::None"):
+            raise exceptions.InvalidConfiguration('The cephfs filesystem '
+                                                  'should not be configured '
+                                                  'for internal ceph cluster')
+
+
 def check_swift_and_rgw(old_env, env, stage):
     """Check that Swift and RGW aren't both enabled in the overcloud
 

tripleoclient/v1/overcloud_deploy.py

@@ -325,6 +325,8 @@ class DeployOvercloud(command.Command):
                     # upgrades: check if swift is deployed
                     utils.check_swift_and_rgw(old_stack_env, env,
                                               self.__class__.__name__)
+        # Validate cephfs filesystem name for internal ceph
+        utils.validate_cephfs_name(env)
         # check migration to new nic config with ansible
         utils.check_nic_config_with_ansible(env)
         # check migration to service vips managed by servce