[eventlet-deprecation] Nova notifier retrieves local thread

A new method to retrieve the local thread is implemented, depending
if the ``thread`` module is monkey patched or not. This is used
in the Nova notifier during the eventlet deprecation migration.

Related-Bug: #2087953
Change-Id: Icc7095d8485acee06cf602ccbf899be22dfc7a53

neutron/common/eventlet_utils.py

@@ -14,8 +14,11 @@
 # under the License.
 
 import os
+import threading
 
 import eventlet
+from eventlet.green import threading as threading_eventlet
+from oslo_utils import eventletutils
 
 
 IS_MONKEY_PATCHED = False
@@ -38,3 +41,9 @@ def monkey_patch():
         p_c_e = importutils.import_module('pyroute2.config.asyncio')
         p_c_e.asyncio_config()
         IS_MONKEY_PATCHED = True
+
+
+def get_threading_local():
+    if eventletutils.is_monkey_patched('thread'):
+        return threading_eventlet.local()
+    return threading.local()

neutron/notifiers/nova.py

@@ -15,7 +15,6 @@
 
 import contextlib
 
-from eventlet.green import threading
 from keystoneauth1 import exceptions as ks_exceptions
 from keystoneauth1 import loading as ks_loading
 from neutron_lib.callbacks import events
@@ -35,6 +34,7 @@ from oslo_utils import uuidutils
 from sqlalchemy.orm import attributes as sql_attr
 import tenacity
 
+from neutron.common import eventlet_utils
 from neutron.notifiers import batch_notifier
 
 
@@ -53,7 +53,7 @@ NOTIFIER_ENABLE_DEFAULT = True
 # callbacks from the agents (DHCP, L2), trying to update the provisioning
 # status of a port. In order to handle each context notifier enable flag, a
 # thread local variable is used.
-_notifier_store = threading.local()
+_notifier_store = eventlet_utils.get_threading_local()
 
 
 @registry.has_registry_receivers