OVS Agent should fail when enable_distributed_routing = True and l2_population = False

[Itzik Brown]

l2_population is required for DVR both as a mechanism driver and as an option in OVS Agent's configuration.
The agent should fail to start when enable_distributed_routing = True and l2_population = False otherwise the router won't behave as expected.

Version
======
RHEL 7.0
openstack-neutron-2014.2.1-6.el7ost.noarch
openstack-neutron-ml2-2014.2.1-6.el7ost.noarch
python-neutron-2014.2.1-6.el7ost.noarch
openstack-neutron-openvswitch-2014.2.1-6.el7ost.noarch

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/165311

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/165311
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=45cbe9fd9ad3ee872a75e78d6af0618baac0f89d
Submitter: Jenkins
Branch: master

commit 45cbe9fd9ad3ee872a75e78d6af0618baac0f89d
Author: Gal Sagie <email address hidden>
Date: Wed Mar 18 08:36:29 2015 +0200

    Validate when DVR enabled, l2_pop is also enabled

    The agent should fail to start when
    enable_distributed_routing = True and l2_population = False
    otherwise the router won't behave as expected.

    All the cross subnet traffic (between VMs of the same tenant)
    in DVR is now handled locally on the compute node using the router namespace.
    A Linux namespace is created for every virtual router,
    on each compute node that hosts VMs that are connected to that router.

    The local DVR performs the routing and replaces the source MAC address and
    the destination MAC address for every packet leaving the compute node.
    In order to do that correctly, the router must be populated with
    all the L2 addresses of the attached networks

    Change-Id: Id2b56d852eff4773a347f490b19ad9eefc86af9c
    Closes-Bug: #1417633
    Co-Authored-By: Romil Gupta <email address hidden>

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/166707

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/166707
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=1c49571d296db07deb766149fe66756b5b4db66a
Submitter: Jenkins
Branch: master

commit 1c49571d296db07deb766149fe66756b5b4db66a
Author: Romil Gupta <email address hidden>
Date: Sun Mar 22 23:38:00 2015 -0700

    Follow up patch for Validate when DVR enabled, l2_pop is also enabled

    Reference:
    https://review.openstack.org/#/c/165311/

    For a VLAN underlays, DVR does not mandate l2-pop to be turned ON.

    So just checking for enable_tunneling and validating for l2-pop being
    turned ON is more than sufficient.

    Change-Id: I96695dc623b4ea37d3ef1384eb9ac9c1384d3da3
    Closes-Bug: #1417633

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: neutron-pecan
Review: https://review.openstack.org/185072