- The configuration option ``api_version`` in the ``ironic`` group was
marked as deprecated and will be removed in the future. The only
possible value for that configuration was "1" (because Ironic only has 1
API version) and the Ironic team came to an agreement that setting the API
version via configuration option should not be supported anymore. As the
Ironic driver in Nova requests the Ironic v1.8 API, that means that
Nova 13.0.0 ("Mitaka") requires Ironic 4.0.0 ("Liberty") or newer if
you want to use the Ironic driver.