Comment 36 for bug 1927277

Reviewed: https://review.opendev.org/c/openstack/charm-ceilometer-agent/+/899054
Committed: https://opendev.org/openstack/charm-ceilometer-agent/commit/3956370e96e39d296691943ad75e3ecff805aa21
Submitter: "Zuul (22348)"
Branch: stable/wallaby

commit 3956370e96e39d296691943ad75e3ecff805aa21
Author: Aurelien Lourot <email address hidden>
Date: Tue Sep 28 14:19:08 2021 +0200

    Publish releases packages map to principal charm

    For principal - subordinate plugin type relations where the
    principal Python payload imports code from packages managed by a
    subordinate, upgrades can be problematic.

    This change will allow a subordinate charm that have opted into the
    feature to inform its principal about all implemented release -
    packages combinations ahead of time. With this information in place
    the principal can do the upgrade in one operation without risk of
    charm relation RPC type processing at a critical moment.

    This is similar to
    https://review.opendev.org/c/openstack/charm-interface-keystone-domain-backend/+/781658
    https://review.opendev.org/c/openstack/charm-layer-openstack/+/781624

    The openstacksdk version is pinned in test-requirements.txt to enabled
    py36 unit tests to run successfully.

    Depends-On: https://review.opendev.org/c/openstack/charm-ceilometer-agent/+/870227
    Change-Id: Ibd5bdcb141fc3103ee97123ff284fb2957802eba
    Closes-Bug: #1927277
    (cherry picked from commit be45f7794504514ffbd4bc721af8f3df9a4c6038)