mgr/cephadm: do not delete smb fs cephx keys

This change effectively disables fencing for the smb service because
the previous attempt to implement fencing would destroy the only
cephx key. Deleting this key would prevent any smb service part of
the logical cluster from talking to cephfs, even ones that were not
to be fenced.

The whole concept of fencing and ranks needs a bit of a rethink in
regards to smb. For now, we're just going to rely on ctdb and not
cephadm for smb's HA.

Fixes: 6030036
Signed-off-by: John Mulligan <[email protected]>

Author: phlogistonjohn

src/pybind/mgr/cephadm/services/smb.py

@@ -34,11 +34,9 @@ def ranked(self, spec: ServiceSpec) -> bool:
         return 'clustered' in smb_spec.features
 
     def fence(self, daemon_id: str) -> None:
-        logger.info(f'Fencing old smb.{daemon_id}')
-        ret, out, err = self.mgr.mon_command({
-            'prefix': 'auth rm',
-            'entity': f'client.smb.fs.cluster.{daemon_id}',
-        })
+        # ... but fencing still wont do anything real, because we
+        # do not have per-service keys. but logging is fun
+        logger.debug('Will not fence key for smb cluster %r', daemon_id)
 
     def fence_old_ranks(
         self,
@@ -47,11 +45,11 @@ def fence_old_ranks(
         num_ranks: int,
     ) -> None:
         smb_spec = cast(SMBSpec, spec)
+        logger.info('Fencing called for smb.%s', smb_spec.cluster_id)
         for rank, m in list(rank_map.items()):
             if rank >= num_ranks:
                 for daemon_id in m.values():
                     if daemon_id is not None:
-                        logger.info(f'Fencing old smb.{smb_spec.cluster_id}')
                         self.fence(smb_spec.cluster_id)
                 del rank_map[rank]
                 self.mgr.spec_store.save_rank_map(spec.service_name(), rank_map)
@@ -60,7 +58,6 @@ def fence_old_ranks(
                 for gen, daemon_id in list(m.items()):
                     if gen < max_gen:
                         if daemon_id is not None:
-                            logger.info(f'Fencing old smb.{smb_spec.cluster_id}')
                             self.fence(smb_spec.cluster_id)
                         del rank_map[rank][gen]
                         self.mgr.spec_store.save_rank_map(spec.service_name(), rank_map)