Fellow Devs, as you might have noticed I started taking care of openstack/js-openstack-lib, now under the openstacksdk umbrella [1]. First goal is to modernize the CI to use Zuul v3, current devstack and nodejs, still WIP [2]. As part of the original suite of tests, the unit and functional tests are run from browsers as well as from node. And, as you may know, browsers care about CORS [3]. js-openstack-lib is connecting to various OpenStack APIs (currently limited to keystone, glance, neutron and nova) to act on behalf of the user (just like openstacksdk/client does). oslo.middleware, as used by those APIs, provides a way to configure CORS by setting params in the [cors] group but uWSGI seemingly ignores that completely [4]. I had to switch to mod_wsgi+apache instead of uwsgi+apache to get past that issue. I could not reproduce locally because kolla (thankfully) uses mostly mod_wsgi atm. The issue I see is that uWSGI is proposed as the future and mod_wsgi is termed deprecated. However, this means the future is broken w.r.t. CORS and so any modern web interface with it if not sitting on the exact same host and port (which is usually different between OpenStack APIs and any UI). [1] https://review.opendev.org/701854 [2] https://review.opendev.org/702132 [3] https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS [4] https://github.com/unbit/uwsgi/issues/1550 -yoctozepto