def get_cluster_ueid(session):
    """Get the Kubernetes Cluster UEID.

    :raises LookupError: If a Cluster UEID cannot be found.

    :returns: A :class:`cobe.UEID` for the Cluster.
    """
    results = session.pluginmanager.hooks.entityd_find_entity(name=
        'Kubernetes:Cluster', attrs=None)
    if results:
        for cluster_entity in results[0]:
            return cluster_entity.ueid
    else:
        raise LookupError('Could not find the Cluster UEID')
