Comment 37 for bug 1453350

Reviewed: https://review.openstack.org/455790
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=bc979efdb85b3ac2722d6607485d21e002718e02
Submitter: Jenkins
Branch: master

commit bc979efdb85b3ac2722d6607485d21e002718e02
Author: Jakub Libosvar <email address hidden>
Date: Tue Apr 11 12:27:46 2017 -0400

    fullstack: Don't let dhcp agents failover

    It turned out dhcp tests work only because agents are considered dead
    after 10 seconds while they report to server every 60 seconds. This led
    to calling network resync after agent revival and hiding the fact dhcp
    agent is not capable of receiving any amqp messages.

    This patch sets the report interval of agents to the half of
    agent_down_time on server side and uses eventlet dhcp agent in order to
    trigger eventlet monkey patching code.

    Eventlet was behind the failure with messages not getting processed. As
    [1] notes: "Note: If the “eventlet” executor is used, the threading and
    time library need to be monkeypatched."

    Because each port calls dhclient to obtain IP address and each dhclient
    instance overwrites /etc/resolv.conf there was added a script that
    generates fullstack-dhclient-script from an existing dhclient-script
    before starting fulltstack tests. This generated script is passed to
    each dhclient process running in fake fullstack machine using -sf
    parameter.

    [1] https://docs.openstack.org/developer/oslo.messaging/server.html

    Related-bug: 1453350

    Change-Id: I0336176b9c364fe3a95be5cef9e7a3af1ef9d7e9