Cloned from launchpad blueprint https://blueprints.launchpad.net/python-glanceclient/+spec/metadata-schema-catalog-support.
There is a Glance project blueprint for metadata schema catalog (https://review.openstack.org/#/c/98554/4). It's still under review, but hopefully it will be accepted for Juno. python-glanceclient should also support this new REST API and this blueprint addresses it.
Specification URL (additional information):