Hello,


I have had some local discussions with gmann, but I'd really like to move this discussion forward
to fix the broken stable/xena gate in heat so I will start this thread, hoping the thread can provide
more context behind my proposal.

Historically stable branches of heat have been frequently affected by any change in requirements
of tempest. This is mainly because in our CI we install our own in-tree integration tests[1] into
tempest venv where tempest and heat-tempest-plugin are installed. Because in-tree integration tests
are tied to that specific stable branch, this has been often causing conflicts in requirements
(master constraint vs stable/X constraint).

[1]
https://github.com/openstack/heat/tree/master/heat_integrationtests

In the past we changed our test installation[2] to use stable constraint to avoid this conflicts,
but this approach does no longer work since stable/xena because

1. stable/xena u-c no longer includes tempest

2. latest tempest CAN'T be installed with stable/xena u-c because current tempest requires
    fasteners>=0.16.0 which conflicts with 0.14.1 in stable/xena u-c.

[2]
https://review.opendev.org/c/openstack/heat/+/803890
https://review.opendev.org/c/openstack/heat/+/848215

I've proposed the change to pin tempest[3] in stable/xena u-c so that people can install tempest
with stable/xena u-c.
[3] https://review.opendev.org/c/openstack/requirements/+/878228

I understand the reason tempest was removed from u-c was that we should use the latest tempest
to test recent stable releases.I agree we can keep tempest excluded for stable/yoga and onwards
because tempest is installable with their u-c, but stable/xena u-c is no longer compatible with master.
Adding pin to xena u-c does not mainly affect the policy to test stable branches with latest tempest
because for that we anyway need to use more recent u-c.

I'm still trying to find out the workaround within heat but IMO adding tempest pin to stable/xena u-c
is harmless but beneficial in case anyone is trying to use tempest with stable/xena u-c.

Thank you,
Takashi Kajinami