---
features:
  - Added support for Keystone middleware feature where if service token is
    sent along with the user token, then it will ignore the expiration of user
    token. This helps deal with issues of user tokens expiring during long
    running operations, such as live-migration where nova tries to access
    Cinder and Neutron at the end of the operation using the user token that
    has expired. In order to use this functionality a service user needs to
    be created. Add service user configurations in ``nova.conf`` under
    ``service_user`` group and set ``send_service_user_token`` flag to
    ``True``. The minimum Keystone API version 3.8 and Keystone middleware
    version 4.12.0 is required to use this functionality.
    This only currently works with Nova - Cinder and Nova - Neutron API
    interactions.