To be able to make changes in request_spec passed in create_volume calls
(in c-sch and c-vol RPC API) while supporting rolling upgrades we need
to convert it from arbitrary dict blob to a well-defined versioned
object. This commit does so while maintaining backwards compatibility
with Mitaka. When version is pinned to Mitaka we're serializing the
dict before sending and when receiving a dict we're converting it to the
object.
We actually have a lot of duplicated/unused data sent using request_spec
and filter_properties. We should start to clean that up.
The future patches should:
* Convert filter_properties to ovo.
* Make services use only one occurrence of the data.
* Remove the unused duplicates while maintaining backwards compatibility
through object translations.
Change-Id: I7dae83667a1aca92c552fbfaa1e90c6558e293bf
Partial-Implements: blueprint cinder-objects