Comment 63 for bug 1703709

Reviewed: https://review.opencontrail.org/35591
Committed: http://github.com/Juniper/contrail-controller/commit/eb5cf95db5b1dd8f45544aeaa98cadfda304a3a7
Submitter: Zuul (<email address hidden>)
Branch: master

commit eb5cf95db5b1dd8f45544aeaa98cadfda304a3a7
Author: Sundaresan Rajangam <email address hidden>
Date: Wed Sep 13 14:30:32 2017 -0700

analytics changes to read config from cassandra

At present, contrail-snmp-collector and contrail-topology reads the user
configuration from contrail-api periodically. This patch changes
the scheme to read the user configuration from config database
(cassandra).
- contrail-snmp-collector and contrail-topology no longer connect to
contrail-api.
- On startup, reads the user configuration directly from config
cassandra database.
- Connects to rabbitmq to listen for the user configuration changes for
the desired user configuration objects.

Partial-Bug: #1703709

This patch contains the changes to read user configuration from

Change-Id: I6294dce8c5759bc40538ca93ce7057640bd88d42