Comment 5 for bug 1528349

@Daniel Berrange: If we are moving to an explicit model for image properties, then perhaps the best way to meet that requirement and make this code not specific to Nova is to directly pass all the required image properties to the signature_utils get_verifier method.

I should also add that the Glance and Nova implementations will continue to diverge during the Mitaka cycle, since the Glance implementation has to deprecate an old approach, and the Nova spec will require us to add certificate validation functionality to the Nova implementation.

As compromise to all of the above consideration and with the goal of eliminating duplicate code I propose the following path forward:

1. Amend Nova implementation to take in image properties as individual parameters, not bundled in a dict or ImageMeta object.
2. Remove other Nova-specific aspects of the signature_utils class, but continue implementing the spec and keep the code in Nova for Mitaka.
3. At the beginning of the N development cycle, after Glance no longer has to give deprecation warnings for the outdated approach, merge the signature_utils module into oslo as oslo.signature_utils and remove the duplicate code from Nova and Glance.

Thoughts?