---
upgrade:
  - |
    A deploy-time check now verifies that the ``nova_libvirt`` image contains
    the ``/usr/local/bin/kolla_nova_libvirt_start`` helper before deploying.
    This helper launches ``libvirtd`` alongside ``virtlogd`` and is required
    by current Kolla-Ansible. If you upgrade Kolla-Ansible but continue to
    use an older ``nova_libvirt`` image that predates the helper, the deploy
    now fails fast with an explanatory message instead of leaving the
    container unable to start. Pull or build a matching ``nova_libvirt``
    image, or skip the ``nova-libvirt-script-check`` tag to bypass the check.