For skipauth clients, allow a 'shutdown' verb

To facilitate a clean coordinated shutdown, create a verb so that a termination can be done
and know when it is completed.  Only allow for the 'special' case of 'skipauth', where unix domain
socket connection is in hand and only root or the service owner can access.

confluent_server/confluent/auth.py

@@ -108,6 +108,8 @@ def authorize(name, element, tenant=False, operation='create',
             and the relevant ConfigManager object for the context of the
             request.
     """
+    if operation not in ('create', 'start', 'update', 'retrieve', 'delete'):
+        return None
     user, tenant = _get_usertenant(name, tenant)
     if tenant is not None and not configmanager.is_tenant(tenant):
         return None

confluent_server/confluent/config/configmanager.py

@@ -1123,6 +1123,13 @@ class ConfigManager(object):
         except OSError:
             pass
 
+    @classmethod
+    def shutdown(cls):
+        cls._bg_sync_to_file()
+        if cls._cfgwriter is not None:
+            cls._cfgwriter.join()
+        sys.exit(0)
+
     @classmethod
     def _bg_sync_to_file(cls):
         with cls._syncstate:

confluent_server/confluent/sockapi.py

@@ -184,6 +184,8 @@ def process_request(connection, request, cfm, authdata, authname, skipauth):
                     consession.destroy()
                     return
                 consession.write(data)
+        elif operation == 'shutdown':
+            configmanager.ConfigManager.shutdown()
         else:
             hdlr = pluginapi.handle_path(path, operation, cfm, params)
     except exc.NotFoundException: