Comment 2 for bug 1631949

Reviewed: https://review.openstack.org/384496
Committed: https://git.openstack.org/cgit/openstack/kolla/commit/?id=dc0c07e0bf54cd461799716be438c708841d386e
Submitter: Jenkins
Branch: master

commit dc0c07e0bf54cd461799716be438c708841d386e
Author: Paul Bourke <email address hidden>
Date: Wed Nov 16 14:12:38 2016 +0000

    Add a 'fallback mode' to disable udev in find_disks

    As part of change I362b3f8e91de79687fc84e256996fbcaf303b6af a check was
    added to use udev to read GPT labels only if the version of udev
    installed supports that, otherwise fallback to sgdisk.

    Unfortunately the check for udev version is unreliable, as it is
    returning the version of the udev userspace tools installed within the
    container rather than on the host.

    As well as this, we're seeing the find_disks.py having trouble reading
    the UUID of a partition via udev. The test system is Oracle VM 3.4.2
    which was released earlier this year, but has an old udev (derivative of
    RHEL 6).

    Even if we use Ansible to query the host's version of udev and pass that
    through to the container, querying the above disk attributes is a
    lottery on older systems without a reliable reference of which versions
    of udev support which operations. Hence we should give operators a
    reliable way to toggle it's usage.

    Partial-Bug: 1631949
    Change-Id: I6ad7825cdb164498f3d02f2ae064c7c1c38e10d5