Comment 5 for bug 1893284

Reviewed: https://review.opendev.org/748550
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=4c11d5467a30506a82dd5d32dd22b8958a187c0b
Submitter: Zuul
Branch: master

commit 4c11d5467a30506a82dd5d32dd22b8958a187c0b
Author: melanie witt <email address hidden>
Date: Thu Aug 27 23:34:18 2020 +0000

    Default user_id when not specified in check_num_instances_quota

    The Quotas.check_deltas method needs a user_id keyword arg in order to
    scope a quota check to a particular user. However, when we call
    check_num_instances_quota we don't pass a project_id or user_id because
    at the time of the quota check, we have not yet created an instance
    record and thus will not use that to determine the appropriate project
    and user.

    Instead, we should rely on the RequestContext.project_id and
    RequestContext.user_id as defaults in this case, but
    check_num_instances_quota only defaults project_id and not user_id.

    check_num_instances_quota should also default user_id to the
    RequestContext.user_id when user_id is not explicitly passed.

    check_num_instances_quota should also check whether any per-user quota
    limits are defined for instance-related resources before passing along
    the user_id to scope resource counting and limit checking. Counting
    resources across a user is costly, so we should avoid it if it's not
    needed.

    Closes-Bug: #1893284

    Change-Id: I3cfb1edc30b0bda4671e0d2cc2a8993055dcc9ff