---
upgrade:
  - |
    Overcloud Ironic must now be configured with the variable
    ``kolla_ironic_enabled_hardware_types``; ``kolla_ironic_drivers`` has been
    removed.
  - |
    Bifrost's ``kolla_bifrost_enable_ipmitool_drivers`` and
    ``kolla_bifrost_enable_pxe_drivers`` variables have been removed. Bifrost
    must now be configured by setting the variable
    ``kolla_bifrost_enabled_hardware_types`` to be a list of hardware types to
    enable.