upper-constraints breaking tests for older tempest builds

[Jake Yip]

We maintain patches to tempest in-house, and realised that tests to tempest<17.0.0 no longer work. This is due to upper-constraints master branch upgrading olsotest to 3.0.0 and moving mockpatch.

I wonder if it is possible to peg upper-constraints in tox.ini to the current stable release, so that tests for commits from now on will still work in the future when they are checked out, even if upper-constraints master branch has libraries with incompatible versions.

We have to patch it like https://review.openstack.org/#/c/533014/ currently in our branch, but if upstream could kindly peg it for each release it'll be great.

[Matthew Treinish (treinish)]

Tempest master follows master global requirements and is branchless meaning we don't have a mechanism to backport changes like that. We also can't land something like 533014 because that will break upstream development.

But, this was anticipated as a potential conflict for downstream consumers doing things similar to you (or just running unit tests on a stable release) and that's why the upper constraints file should be able to override it. Just export UPPER_CONSTRAINTS_FILE="https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt?h=stable/pike" in your pipeline for your downstream fork.

[Jake Yip (waipengyip)]

Thanks a lot for your explanation! We will use that ENV variable in our ci.