There are CLI tests added to Tempest for commands which may not be available yet in released versions of the clients, so downstream packagers would not have those commands available for CI and the tests will fail.
The use case is testing stable/icehouse server code, i.e. nova, with packaged versions of the clients that are supported for the stable/icehouse release of Nova, which is python-novaclient-2.17.0 in the 2014.1 release of the server code.
With branchless Tempest there is no stable/icehouse branch for Tempest, and so when new CLI tests are added to Tempest on master which require commands or other functions in the clients, they can fail for downstream packagers if the required commands/functions are not in released versions of the clients on pypi.python.org, where the packager may be getting their source tar.gz from.
One specific example here is the server-group-list CLI test added for the Nova client which is not in a released version of python-novaclient. Anyone running Tempest against a released version of the client will fail this new CLI test.
Note that the community gate CI does not have an issue with this since Tempest is run against trunk level code for the clients rather than released versions.
Add a simple decorator that can be used in the tempest/cli tests for checking that the installed version of the client is at a minimum version to support the test, otherwise the test is skipped.
The decorator would be applied to feature tests introduced since Icehouse due to the branchless Tempest strategy and the lack of a stable/icehouse branch.
There are not really any good alternatives to this issue for downstream packagers/deployers if they are not running CI against trunk levels of code for the clients. They can reset HEAD for Tempest to some arbitrary commit around the time of the server release they are testing, e.g. sometime around the 2014.1 release for stable/icehouse testing, but then they are frozen to that commit in Tempest and do not get future bug fixes that would have been backported when there were stable branches for Tempest. The other alternative is manually excluding the unsupported CLI tests but this is cumbersome and only works around the issue after the fact rather than putting the check in the code when the test runs.
Write the decorator code. The work in progress patch is here:
Apply the decorator to the CLI tests, with a primary focus on any tests added after the 2014.1 Icehouse release, especially for those tests which require newer client code than what is in a released version.
This is only an issue introduced by the “Branchless Tempest” blueprint but is not technically tied to that blueprint’s implementation, but is listed here for posterity: