In a 3-control/dns node setup, no dns records are seen in Contrail UI

[Vedamurthy Joshi]

R2.20 Build 60 Ubuntu 14.04 Juno Multi-node setup

In this setup, there are 3 control/dns nodes - nodec1, nodec2, nodec3

In a vdns enabled VN vn3, when we queried dns records, no records were seen in the UI

VM was launched on nodek2 who was connected to nodec1 and nodec2

In the contrail-dns introspect, it was seen that nodec1 and nodec2 had dns entries.
nodec3 did not have dns entries.

Looks like the dns entries are got from nodec3 in this case

Per Hari, this is a known discovery-related issue where things work properly on a setup with only 2 contrail-dns nodes

[Rahul (rahuls)]

UI needs to use discovery and subscribe for only 2 dns nodes.

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11990
Submitter: Biswajit Mandal (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11991
Submitter: Biswajit Mandal (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11991
Committed: http://github.org/Juniper/contrail-web-core/commit/495d79a820dd5337f3dbe889dd0e26e32fb77b9a
Submitter: Zuul
Branch: master

commit 495d79a820dd5337f3dbe889dd0e26e32fb77b9a
Author: Biswajit Mandal <email address hidden>
Date: Wed Jun 24 07:49:00 2015 +0530

Closes-Bug: #1467875
Adding discovery service subscribe for dns-server.

Change-Id: Ia9ee6691d0142255bc611e40879a8b7f8a899ccd

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11990
Committed: http://github.org/Juniper/contrail-web-controller/commit/b223b156106d9672ff33555ea7d39b793bccbbb6
Submitter: Zuul
Branch: master

commit b223b156106d9672ff33555ea7d39b793bccbbb6
Author: Biswajit Mandal <email address hidden>
Date: Wed Jun 24 07:46:31 2015 +0530

Closes-Bug: #1467875
Get the dns-node IPs from discovery-server in stead of UVE, and use those to
fetch the DNS sandesh data.

Change-Id: Ibc8a92c45cff97b446fc120b29f4e759e6776fd9