Test & document 1.28 (consumer gen) changes for /resource_providers/{u}/allocations

[Eric Fried]

I978fdea51f2d6c2572498ef80640c92ab38afe65 / https://review.openstack.org/#/c/565604/ added placement microversion 1.28, which made various API operations consumer generation-aware. One of the affected routes was /resource_providers/{u}/allocations - but this route wasn't covered in the gabbi tests or the API reference documentation.

[jichenjc (jichenjc)]

I did some search and found that
https://review.openstack.org/#/c/565604/31/releasenotes/notes/consumer_generation-f576ac2594b24e2e.yaml
says only impact POST and PUT

while
https://github.com/openstack/nova/blob/master/nova/api/openstack/placement/handler.py#L99

only support GET ,so any update should be included? The consumer_generation id ?

[Balazs Gibizer (balazs-gibizer)]

Create a bug in placement storyboard as placement bugs are handled there https://storyboard.openstack.org/#!/story/2006620