Comment 11 for bug 1675343

Reviewed: https://review.openstack.org/465405
Committed: https://git.openstack.org/cgit/openstack-dev/devstack/commit/?id=d1fe0e62e77b2eaf711e0b4c157dc571be9ad13e
Submitter: Jenkins
Branch: master

commit d1fe0e62e77b2eaf711e0b4c157dc571be9ad13e
Author: Kevin Benton <email address hidden>
Date: Tue May 16 22:27:58 2017 -0700

    Always setup libvirt for tap devices when using Neutron

    This logic has been tied to OVS since it was introduced in [1] and
    revised in [2]. However, many other backends may use tap devices that
    aren't related to OVS, such as Calico[3] and Linux Bridge after [4]
    merges.

    This patch just removes the dependency on OVS specifically so
    /dev/net/tun is added to cgroups whenever any Neutron backend is used.
    This is done in other deployment tools like Juju[5] so it's not
    unprecedented.

    1. Ifab268f739b004db13024633e8abeb17691b9e46
    2. Ic1da132fa421f1c70c10a319ee3239831b0f956f
    3.
    http://docs.projectcalico.org/master/getting-started/openstack/installation/ubuntu#compute-node-install
    4. I23c5faaeab69aede1fd038a36f4a0b8f928498ce
    5.
    https://github.com/openstack/charm-nova-compute/blob/2790f81ecd32d9962617c4c3126621fffdc318a0/templates/qemu.conf

    Change-Id: I075595158d8f3b5a6811c4794aa7b91912940db5
    Partial-Bug: #1675343