Comment 5 for bug 1720354

Comment from Doug in IRC (#openstack-glance):
[16:23:25] <dhellmann> rosmaita, jokke_ : regarding the http check policy thing raised in the glance meeting -- the issue with the current ImageTarget class is that it seems to support looking up a single key, but doesn't provide a way to get all of the properties at once
[16:23:46] <dhellmann> the http check needs that because it ships all of the properties to the remote service so that service can enforce the policy
[16:24:00] <dhellmann> and the generic http check doesn't know what properties (a) exist or (b) are needed
[16:25:18] <dhellmann> the API for the enforcer wasn't clear about the expectations for the "target" argument -- we really did assume it was a dict instance, I think. So ImageTarget is behaving sort of like a dict, but not enough to work for all cases