Comment 4 for bug 1606496

Reviewed: https://review.openstack.org/346966
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=af218caba4f532c7d182071ab4304d49d02de08f
Submitter: Jenkins
Branch: master

commit af218caba4f532c7d182071ab4304d49d02de08f
Author: Roman Podoliaka <email address hidden>
Date: Mon Jul 25 20:35:29 2016 +0300

    ironic_host_manager: fix population of instances info on schedule

    IronicHostManager currently overrides the _get_instance_info() method
    of the base class and unconditionally returns an empty dict of
    instances for a given compute node.

    The problem with that is that in a heterogeneous cloud with both
    libvirt and ironic compute nodes this will always return {} for the
    former too, which is incorrect and will effectively break instance
    affinity filters like DifferentHostFilter or SameHostFilter, that
    check set intersections of instances running on a particular host and
    the ones passed as a hint for nova-scheduler in a boot request.

    IronicHostManager should use the method implementation of the base
    class for non-ironic compute nodes.

    This is a partial fix which only modifies _get_instance_info() called
    down the select_destinations() stack. A following change will modify
    _init_instance_info() that pre-populates node instances info on start
    of a nova-scheduler process.

    Partial-Bug: #1606496

    Change-Id: Ib1ddb44d71f7b085512c1f3fc0544f7b00c754fe