Add fluentd-based notification transport

Change-Id: I84de6582603aee57d7f868f6493fce8ae226aa9a
PROD-related: PROD-29185
(cherry picked from commit 276d9292c5c03de0c23172451e4f22e311219322)
diff --git a/defaults/stacklight.yml b/defaults/stacklight.yml
index 1abbb5e..e969319 100644
--- a/defaults/stacklight.yml
+++ b/defaults/stacklight.yml
@@ -1,5 +1,9 @@
 parameters:
   _param:
+    # ELK settings
+    stacklight_elasticsearch_port: 9200
+    stacklight_notification_topic: stacklight_notifications
+
     # ELK stack versions
     elasticsearch_version: 5
     kibana_version: 5