pybind/mgr/status: drop asserts that fight the defaultdict defaults

The 'assert metadata' checks in the status module were actually fighting
against our own defaults. Since an empty defaultdict is falsy, these
asserts would blow up the whole command if a single daemon was down
after a mgr restart.

This drops those four grumpy asserts. Now, instead of a traceback,
`ceph osd status` and `ceph fs status` will just show a blank hostname
 or "unknown" version as intended.

The trigger is common in practice: any mgr restart leaves daemons
that are currently down without metadata in daemon_state, since
they never reconnect via MMgrOpen to repopulate it. After such a
restart, `ceph osd status` and `ceph fs status` blow up:
```
  Error EINVAL: Traceback (most recent call last):
    ...
    File ".../status/module.py", line 340, in handle_osd_status
      assert metadata
  AssertionError
```

The bug was introduced in 5ac2901f54ff

Fixes: https://tracker.ceph.com/issues/76416
Reported-by: Maximiliano Sandoval <m.sandoval@proxmox.com>
Signed-off-by: Kefu Chai <tchaikov@gmail.com>

diff --git a/src/pybind/mgr/status/module.py b/src/pybind/mgr/status/module.py
index bae1136a3d1b2a54b7ddce514a031d9121deea90..de14a9f02dbca4b9dca92c90c839b931b66f01fe 100644 (file)
--- a/src/pybind/mgr/status/module.py
+++ b/src/pybind/mgr/status/module.py
@@ -109,7 +109,6 @@ class Module(MgrModule):
 
                     metadata = self.get_metadata('mds', info['name'],
                                                  default=defaultdict(lambda: 'unknown'))
-                    assert metadata
                     mds_versions[metadata['ceph_version']].append(info['name'])
 
                     if output_format in ('json', 'json-pretty'):
@@ -159,7 +158,6 @@ class Module(MgrModule):
 
                 metadata = self.get_metadata('mds', daemon_info['name'],
                                              default=defaultdict(lambda: 'unknown'))
-                assert metadata
                 mds_versions[metadata['ceph_version']].append(daemon_info['name'])
 
                 if output_format in ('json', 'json-pretty'):
@@ -234,7 +232,6 @@ class Module(MgrModule):
         for standby in fsmap['standbys']:
             metadata = self.get_metadata('mds', standby['name'],
                                          default=defaultdict(lambda: 'unknown'))
-            assert metadata
             mds_versions[metadata['ceph_version']].append(standby['name'])
 
             if output_format in ('json', 'json-pretty'):
@@ -337,7 +334,6 @@ class Module(MgrModule):
             if osd_id in osd_stats:
                 metadata = self.get_metadata('osd', str(osd_id), default=defaultdict(str))
                 stats = osd_stats[osd_id]
-                assert metadata
                 hostname = metadata['hostname']
                 kb_used = stats['kb_used'] * 1024
                 kb_avail = stats['kb_avail'] * 1024