Comment 2 for bug 1680122

yes, cinder seems to omit "volume_image_metadata" in SHOW API if no image metadata passed and not in DB also. Which is not case of detail list where if any volume has image metadata it append "volume_image_metadata" with empty dict for other volumes also.

https://github.com/openstack/cinder/blob/6fff3565211b10a86c46f64d3a180024f5c80bde/cinder/api/contrib/volume_image_metadata.py#L69

On Tempest tests side, all the volume created in this tests are non-bootable and either SHOW or detail list does not return "volume_image_metadata".
So i am not sure how this tests is failing. can you please provide log location or more info where failure happened ?