mgr/cephadm: fix issue with missing prometheus alerts

Files passed as configuration to the cephadm binary had not been created
and mapped to the container, if those files weren't included in the
required files section inside cephadm. This prevented optional file
includes in the configuration.

The configuration file for the Prometheus default alerts is not
mandatory and hence wasn't included in the required files section, still it
needs to be added to the container by cephadm.

This change enables optional files to be included in the configuration
for monitoring components, so that those files are created and mapped
within the container.

Note that a `required_files` variable has been removed at one position
in these changes, though it wasn't used to ensure that required files
were included in the configuration at that point anyway. The test which
ensures that all required files are passed is somewhere else.

Fixes: https://tracker.ceph.com/issues/49856

Signed-off-by: Patrick Seidensal <[email protected]>

src/cephadm/cephadm

@@ -2117,7 +2117,6 @@ def create_daemon_dirs(ctx, fsid, daemon_type, daemon_id, uid, gid,
 
     if daemon_type in Monitoring.components.keys():
         config_json: Dict[str, Any] = get_parm(ctx.config_json)
-        required_files = Monitoring.components[daemon_type].get('config-json-files', list())
 
         # Set up directories specific to the monitoring component
         config_dir = ''
@@ -2145,10 +2144,14 @@ def create_daemon_dirs(ctx, fsid, daemon_type, daemon_id, uid, gid,
             makedirs(os.path.join(data_dir_root, config_dir, 'data'), uid, gid, 0o755)
 
         # populate the config directory for the component from the config-json
-        for fname in required_files:
-            if 'files' in config_json:  # type: ignore
+        if 'files' in config_json:
+            for fname in config_json['files']:
                 content = dict_get_join(config_json['files'], fname)
-                with open(os.path.join(data_dir_root, config_dir, fname), 'w') as f:
+                if os.path.isabs(fname):
+                    fpath = os.path.join(data_dir_root, fname.lstrip(os.path.sep))
+                else:
+                    fpath = os.path.join(data_dir_root, config_dir, fname)
+                with open(fpath, 'w') as f:
                     os.fchown(f.fileno(), uid, gid)
                     os.fchmod(f.fileno(), 0o600)
                     f.write(content)

src/cephadm/tests/test_cephadm.py

@@ -861,3 +861,53 @@ def test_get_version_node_exporter(self, _call):
         _call.return_value = '', '{}, version 0.16.1'.format(daemon_type.replace('-', '_')), 0
         version = cd.Monitoring.get_version(ctx, 'container_id', daemon_type)
         assert version == '0.16.1'
+
+    @mock.patch('cephadm.os.fchown')
+    @mock.patch('cephadm.get_parm')
+    @mock.patch('cephadm.makedirs')
+    @mock.patch('cephadm.open')
+    @mock.patch('cephadm.make_log_dir')
+    @mock.patch('cephadm.make_data_dir')
+    def test_create_daemon_dirs_prometheus(self, make_data_dir, make_log_dir, _open, makedirs,
+                                           get_parm, fchown):
+        """
+        Ensures the required and optional files given in the configuration are
+        created and mapped correctly inside the container. Tests absolute and
+        relative file paths given in the configuration.
+        """
+
+        fsid = 'aaf5a720-13fe-4a3b-82b9-2d99b7fd9704'
+        daemon_type = 'prometheus'
+        uid, gid = 50, 50
+        daemon_id = 'home'
+        ctx = mock.Mock()
+        ctx.data_dir = '/somedir'
+        files = {
+            'files': {
+                'prometheus.yml': 'foo',
+                '/etc/prometheus/alerting/ceph_alerts.yml': 'bar'
+            }
+        }
+        get_parm.return_value = files
+
+        cd.create_daemon_dirs(ctx,
+                              fsid,
+                              daemon_type,
+                              daemon_id,
+                              uid,
+                              gid,
+                              config=None,
+                              keyring=None)
+
+        prefix = '{data_dir}/{fsid}/{daemon_type}.{daemon_id}'.format(
+            data_dir=ctx.data_dir,
+            fsid=fsid,
+            daemon_type=daemon_type,
+            daemon_id=daemon_id
+        )
+        assert _open.call_args_list == [
+            call('{}/etc/prometheus/prometheus.yml'.format(prefix), 'w'),
+            call('{}/etc/prometheus/alerting/ceph_alerts.yml'.format(prefix), 'w'),
+        ]
+        assert call().__enter__().write('foo') in _open.mock_calls
+        assert call().__enter__().write('bar') in _open.mock_calls