Comment 16 for bug 1565801

Reviewed: https://review.openstack.org/344658
Committed: https://git.openstack.org/cgit/openstack/neutron-lbaas/commit/?id=8c01eff53b2d399fe63d62a55b13487877e8a0b7
Submitter: Jenkins
Branch: master

commit 8c01eff53b2d399fe63d62a55b13487877e8a0b7
Author: Nir Magnezi <email address hidden>
Date: Wed Jul 20 10:31:28 2016 +0300

    Implements ProcessMonitor in the haproxy driver

    The ProcessMonitor class will monitor spawned external processes.

    This patch enhances the HaproxyNSDriver class (v2) to utilize the
    external_process module in order to monitor and respawn the haproxy
    processes if and when needed.

    With this patch the LBaaS agent (v2) will load external_process related
    options in order to take a configured action when haproxy process
    dies unexpectedly.

    This is the second attempt to introduce ProcessMonitor in the haproxy
    driver. The first attempt I420ca20b2620487909885e0e9f08dae60ebec2bf
    caused an issue where haproxy failed to acquire new configuration, due
    to the lack of -sf flags which should be provided when haproxy.conf is
    being updated. More information about the flags here[1]

    [1] http://www.haproxy.org/download/1.2/doc/haproxy-en.txt

    Co-Authored-By: Thomas Herve <email address hidden>
    Closes-Bug: #1565801
    Related-Bug: #1603860

    Change-Id: Ia47b1586be17be421e01c131859dd0d50b1d7db6