---
upgrade:
  - |
    Support for hooks has been removed. In previous versions of nova, these
    provided a mechanism to extend nova with custom code through a plugin
    mechanism. However, they were deprecated in 13.0.0 (Mitaka) as
    unmaintainable long-term. `Versioned notifications`__ and `vendordata`__
    should be used instead.
    For more information, refer to `this thread`__.

    __ https://docs.openstack.org/nova/latest/reference/notifications.html
    __ https://docs.openstack.org/nova/latest/admin/vendordata.html
    __ http://lists.openstack.org/pipermail/openstack-dev/2016-February/087782.html