test-requirements are wrongly installed system-wide

[Michal Ptacek]

test-requirements are installed system-wide
https://github.com/openstack-dev/devstack/blob/6523d6e09789076d0a430bf7b608511fcb1c406a/inc/python#L336-L348
which is wrong as it might impact other system configuration

virtualenv concept was brought in
https://review.openstack.org/#/c/151513/
and most likely not covering test-requirements part properly

in our understanding there is gap in processing test-requirements where it's not configurable and always deployed system-wide

[sean mooney (sean-k-mooney)]

maybe a concert example of why this is bad is useful.
Michal works on the intel NFV CI and a recent change to nova
https://review.openstack.org/#/c/435575/
added a new requirement to the test-requirements.txt file.

following this change flake8-import-order is now installed systemwide.
as a result when we build ovs-dpdk from source in our thridparty ci
the automatic execution of pep8 testing as part of the ovs makefile
now fails due to the fact that openvswitch does not require strict ordering
of import for there python bindings.

as a result because the test-requirement are installed system wide instead of in virtual environments when they are run via tox the compilation of ovs was broken due to the introduction of a new test requrement to nova.

introducing a new devstack varible
GLOBAL_INSTALL_TEST_REQS that wrapped
https://github.com/openstack-dev/devstack/blob/6523d6e09789076d0a430bf7b608511fcb1c406a/inc/python#L336-L348
in an if would allow us to disable this behavior and also speed up our devstack deployment
as we do not run unit test in the thirdpart ci.

for the general devstack user it is also of benifit as you typically do not need the test-requirements for all project to be installed just the ones you contribute too and in this case
you will typically use tox to execute the test in a venv that will not use the system packages anyway.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/444788

[OpenStack Infra (hudson-openstack)]

Change abandoned by Jens Harbott (frickler) (<email address hidden>) on branch: master
Review: https://review.openstack.org/444788
Reason: This patch is in merge conflict for over a year. Feel free to reopen and fix conflicts if you want to continue with this.

[Dr. Jens Harbott (j-harbott)]

Please update if this issue still exists.

[Launchpad Janitor (janitor)]

[Expired for devstack because there has been no activity for 60 days.]