misc: aggregate environment change signals (#11308)

hobo/deploy/signals.py

@@ -14,10 +14,13 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import threading
+
 from celery import Celery
 from kombu.common import Broadcast
 
 from django.conf import settings
+from django.core.signals import request_finished
 from django.db.models.signals import post_save
 from django.dispatch import receiver
 
@@ -27,10 +30,24 @@ from hobo.environment.models import Variable, AVAILABLE_SERVICES
 from hobo.profile.models import AttributeDefinition
 
 
+class Local(threading.local):
+    MUST_NOTIFY = False
+
+tls = Local()
+
+
 @receiver(post_save)
-def notify_agents(sender, instance, **kwargs):
+def post_environment_save(sender, instance, **kwargs):
     if not sender in [Variable, AttributeDefinition] + AVAILABLE_SERVICES:
         return
+    tls.MUST_NOTIFY = True
+
+
+@receiver(request_finished)
+def notify_agents(sender, **kwargs):
+    if not tls.MUST_NOTIFY:
+        return
+    tls.MUST_NOTIFY = False
     with Celery('hobo', broker=settings.BROKER_URL) as app:
         app.conf.update(
             CELERY_TASK_SERIALIZER='json',