Comment 19 for bug 1974070

Reviewed: https://review.opendev.org/c/openstack/nova/+/868010
Committed: https://opendev.org/openstack/nova/commit/b881dd25b4abb3c54934d8ebbccb2ac602c83177
Submitter: "Zuul (22348)"
Branch: stable/yoga

commit b881dd25b4abb3c54934d8ebbccb2ac602c83177
Author: John Garbutt <email address hidden>
Date: Wed May 18 19:06:36 2022 +0100

    Ironic: retry when node not available

    After a baremetal instance is deleted, and its allocation is removed
    in placement, the ironic node might start cleaning. Eventually nova
    will notice and update the inventory to be reserved.
    During this window, a new instance may have already picked this
    ironic node.

    When that race happens today the build fails with an error:
    "Failed to reserve node ..."

    This change tries to ensure the remaining alternative hosts are
    attempted before aborting the build.
    Clearly the race is still there, but this makes it less painful.

    Related-Bug: #1974070
    Change-Id: Ie5cdc17219c86927ab3769605808cb9d9fa9fa4d
    (cherry picked from commit 8a476061c5e034016668cd9e5a20c4430ef6b68d)
    (cherry picked from commit d71e9f6ec4933f9430db55537a36678b16ce895a)