---
upgrade:
  - |
    This release replaces node scheduling based on properties (CPU count,
    memory and disk) with scheduling based on *custom resource classes*.
    As part of this change during the upgrade:

    * The ``resource_class`` field is set to ``baremetal``, if empty.
    * The standard flavors are adjusted to request one instance of the
      ``baremetal`` resource class and to **not** request the standard
      properties. Flavors that already have a resource class attached are
      not changed.

    All non-standard custom flavors have to be changed in a similar way.

    See the `ironic flavor documentation
    <https://docs.openstack.org/ironic/latest/install/configure-nova-flavors.html#scheduling-based-on-resource-classes>`_
    for details.