Comment 26 for bug 1495702

Reviewed: https://review.opencontrail.org/17834
Committed: http://github.org/Juniper/contrail-controller/commit/8a30644055aeec528a6223223adc5a1d9f76b925
Submitter: Zuul
Branch: R3.0

commit 8a30644055aeec528a6223223adc5a1d9f76b925
Author: Divakar <email address hidden>
Date: Thu Oct 15 16:11:50 2015 +0530

Taking the haproxy process id from config.pid file

The haproxy config is updated by providing the new configuration file
and old haproxy process id. This starts a new haproxy process letting
the old haproxy process to handle the old sessions. New haproxy handles
the new sessions. If a new configuration update comes while both old and
new haproxy processes are runnning, another haproxy process needs to be started
by providing the latest running haproxy process id.

In the existing update code, the haproxy process id is found by "ps"
output. This is resulating in not getting the latest haproxy process id,
but an older process id. This is leading to second haproxy process never
getting killed leaving two haproxies running for ever.

The latest haproxy process that is handling the new session is always
updated in a file by haproxy itself. As a fix, this process id used to
start a new haproxy rather taking the pid from "ps". When the
loadbalancer VIP is deleted, Agent deletes the directory where haproxy
config file, stats file and pid file are stored. This can result in
vrouter_netns.py script failing as pid is not found to stop the haproxy.
To overcome this, the config file, pid file and sock file are stored not
in an explicit directory corresponding to the pool. Only config fike and
sock file are deleted by Agent and pid file is deleted by vrouter_netns
script.

closes-bug: #1495702

Conflicts:
 src/nodemgr/vrouter_nodemgr/haproxy_stats.py
 src/vnsw/agent/oper/instance_manager.cc
 src/vnsw/agent/oper/netns_instance_adapter.cc
 src/vnsw/agent/oper/test/instance_manager_test.cc
 src/vnsw/opencontrail-vrouter-netns/opencontrail_vrouter_netns/vrouter_netns.py

Change-Id: If5fd9be0c5229aa68f4b104d3a566f6ac612814e