[L3] Add some logs for router processing

In order to dig the real action of a ResourceUpdate, add logs for:
1. add/update router
2. delete router
3. delete namespace
4. agent extension router add/delete/update actions

Change-Id: I5c0ff485cd0c966afe535f8063deca6e410e012d
Related-bug: #1881995

neutron/agent/l3/agent.py

@@ -546,6 +546,8 @@ class L3NATAgent(ha.AgentMixin,
         except Exception:
             with excutils.save_and_reraise_exception():
                 self.router_info[router_id] = ri
+        LOG.debug("Router info %s delete action done, "
+                  "and it was removed from cache.", router_id)
 
         registry.notify(resources.ROUTER, events.AFTER_DELETE, self, router=ri)
 
@@ -610,8 +612,12 @@ class L3NATAgent(ha.AgentMixin,
             raise l3_exc.RouterNotCompatibleWithAgent(router_id=router['id'])
 
         if router['id'] not in self.router_info:
+            LOG.debug("Router %s info not in cache, "
+                      "will do the router add action.", router['id'])
             self._process_added_router(router)
         else:
+            LOG.debug("Router %s info in cache, "
+                      "will do the router update action.", router['id'])
             self._process_updated_router(router)
 
     def _process_added_router(self, router):
@@ -738,7 +744,7 @@ class L3NATAgent(ha.AgentMixin,
                     # processing queue (like events from fullsync) in order to
                     # prevent deleted router re-creation
                     rp.fetched_and_processed(update.timestamp)
-                LOG.info("Finished a router update for %s, update_id %s. "
+                LOG.info("Finished a router delete for %s, update_id %s. "
                          "Time elapsed: %.3f",
                          update.id, update.update_id,
                          update.time_elapsed_since_start)

neutron/agent/l3/l3_agent_extensions_manager.py

@@ -46,6 +46,8 @@ class L3AgentExtensionsManager(agent_ext_manager.AgentExtensionsManager):
                     "implement method add_router",
                     {'name': extension.name}
                 )
+        LOG.debug("L3 agent extension(s) finished router %s "
+                  "add action.", data['id'])
 
     def update_router(self, context, data):
         """Notify all agent extensions to update router."""
@@ -58,6 +60,8 @@ class L3AgentExtensionsManager(agent_ext_manager.AgentExtensionsManager):
                     "implement method update_router",
                     {'name': extension.name}
                 )
+        LOG.debug("L3 agent extension(s) finished router %s "
+                  "update action.", data['id'])
 
     def delete_router(self, context, data):
         """Notify all agent extensions to delete router."""
@@ -70,6 +74,8 @@ class L3AgentExtensionsManager(agent_ext_manager.AgentExtensionsManager):
                     "implement method delete_router",
                     {'name': extension.name}
                 )
+        LOG.debug("L3 agent extension(s) finished router %s "
+                  "delete action.", data['id'])
 
     def ha_state_change(self, context, data):
         """Notify all agent extensions for HA router state change."""

neutron/privileged/agent/linux/ip_lib.py

@@ -521,6 +521,7 @@ def remove_netns(name, **kwargs):
     except OSError as e:
         if e.errno != errno.ENOENT:
             raise
+    LOG.debug("Namespace %s deleted.", name)
 
 
 @privileged.namespace_cmd.entrypoint