Comment 5 for bug 1723423

Reviewed: https://review.openstack.org/513678
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=d25feca90ec4bad6ec9ececedced63b9f00b4c87
Submitter: Zuul
Branch: stable/pike

commit d25feca90ec4bad6ec9ececedced63b9f00b4c87
Author: Dmitry Tantsur <email address hidden>
Date: Fri Oct 13 15:18:16 2017 +0200

    Pick ironic nodes without VCPU set

    Starting with the Pike release, reporting VCPU/memory/disk is no longer required.
    However, we used VCPU to check if a node is available, so nodes without VCPU in
    their properties were always ignored. This patch changes the logic to use the existing
    _node_resources_unavailable call.

    This change also fixes another related issue: when disk or memory are missing from
    properties, the virt driver tries to report zero max_unit for them, which is not
    allowed by placement.

    Change-Id: I1bbfc152189252c5c45e6153695a802d17b76690
    Closes-Bug: #1723423
    (cherry picked from commit b25928dc0459e44c5cef8c1f16db76d779fbf556)