Code review comment for ~rafaeldtinoco/ubuntu/+source/simplestreams:xenial-1686437-keystone-v3

The summary of this MP itemizes 6 patches, but the series file in the debdiff shows 8 patches added and 1 removed:

> -keystone-v3-support.patch
> +428-do-not-require-that-hypervisor_config-be-present.patch
> +433-glance-ignore-inactive-images.patch
> +435-glance-refactor-for-testing.patch
> +436-glance-fix-race-conditions.patch
> +skip-openstack-tests-if-no-libs.patch
> +450-453-454-keystone-v3-support.patch
> +455-nova-lxd-support-squashfs-images.patch
> +460-glance-handle-v2-auth-with-sessions.patch

I'd like to see the skip openstack tests and the 435 refactor mentioned in the changelog for completeness. 435 in particular adds/modifies a lot of code.

As others appear to have covered testing for this, I am mostly focusing on code review. I verified the various components of this patchset have gone through adequate levels of review. I've read through the debdiff itself looking for obvious flaws; I might implement a few things differently but am spotting nothing worth flagging as problematic.