Comment 13 for bug 1727500

Reviewed: https://review.opencontrail.org/38530
Committed: http://github.com/Juniper/contrail-controller/commit/c5a128c4b6575201cc3431ddfa76859626ad293b
Submitter: Zuul (<email address hidden>)
Branch: R3.2

commit c5a128c4b6575201cc3431ddfa76859626ad293b
Author: Piyush Srivastava <email address hidden>
Date: Tue Dec 19 11:35:33 2017 -0800

Adding TLS support for config services to cassandra

This change adds support for TLS encrypted communication between config
services and Cassandra. Following arguments are added to enable TLS
support -

`cassandra_use_ssl` - when set to true, enables tls communication
`cassandra_ca_certs` - path to ca certs to use to perform ssl validation

Both of the above parameters are optional, service connects to Cassandra
using an uncrypted connection when the above parameters are not
specified.

TLS for cassandra is enabled for the following config services -

schema-transformer
api-server
svc-monitor
device-manager
discovery

Closes-Bug: 1727500
Change-Id: I929e0f563f7076b5ada13b6f4e7adad339c47534