Separated "provides" and "observes" declarations in sync steps. Provides is for dependency management and observes is for retrieving obejcts that have changed.
diff --git a/planetstack/openstack_observer/steps/sync_controller_images.py b/planetstack/openstack_observer/steps/sync_controller_images.py
index fa0cad1..e076d81 100644
--- a/planetstack/openstack_observer/steps/sync_controller_images.py
+++ b/planetstack/openstack_observer/steps/sync_controller_images.py
@@ -13,6 +13,7 @@
 
 class SyncControllerImages(OpenStackSyncStep):
     provides=[ControllerImages]
+    observes = ControllerImages
     requested_interval=0
 
     def fetch_pending(self, deleted):