Comment 1 for bug 1938595

Well, this is heartening - the problem is caused by #1938594. Looks like cinder depends on swift for some reason to talk to glance when downloading volumes, so when the v3 token issued to swift and used by the RGWs expires, it somehow creates the same breaking condition seen in Canonical's default config (`show_image_direct_url=True`) when using multiple Cinder back-ends.

I'm not sure we should close this as a duplicate until #1938594 is resolved because anyone searching for that error code will run into the "other cause" in Google search results instead of being led here.