Comment 5 for bug 1823370

Reviewed: https://review.opendev.org/650429
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=95df2a239c32f2ee5d00f06a59a9e91b59f3aca5
Submitter: Zuul
Branch: master

commit 95df2a239c32f2ee5d00f06a59a9e91b59f3aca5
Author: Matt Riedemann <email address hidden>
Date: Fri Apr 5 15:36:00 2019 -0400

    Restrict RequestSpec to cell when evacuating

    When evacuating a server in a multi-cell environment
    we need to restrict the scheduling request during
    evacuate to the cell in which the instance already exists
    since we don't support cross-cell evacuate.

    This fixes the issue by restricting the RequestSpec to
    the instance's current cell during evacuate in the same
    way we do during unshelve.

    Note that this should also improve performance when
    rebuilding a server with a new image since we will only
    look for the ComputeNode from the targeted cell rather
    than iterate all enabled cells during scheduling.

    Change-Id: I497180fb81fd966d1d3d4b54ac66d2609347583e
    Closes-Bug: #1823370