Comment 1 for bug 1938151

If the image is large, then you likely need to increase your glance quota size in your job. I'm not sure why it's getting a 500 like that, as I don't see anything in the logs about that on look. Since you're using a fedora image, I'm guessing that's the problem.

https://github.com/openstack/devstack/blob/master/doc/source/configuration.rst#glance