We should store the glance image id as UUID to be consistent with OpenStack instance id, network id and so on.
Specifically this is referring to the SQLAlchemy-level database type of the openstack_region.ipxe_image_id column, which is currently Unicode in SQLAlchemy (VARCHAR in the database). It should be UUID in SQLAlchemy (BINARY or whatever it is in the database). All the places that refer to this property in Python code will need to be adjusted to handle the UUID type (everything might just work as is). And we will need a database migration script to change the column's type *and* correctly preserve the existing values. This might be the hardest part.
https://gerrit.beaker-project.org/#/c/5774/
Beaker 25.0 has been released. Release notes are available upstream: https://beaker-project.org/docs/whats-new/release-25.html