def _strip_unsafe_kubernetes_special_chars(string: str) -> str:
    """
    Kubernetes only supports lowercase alphanumeric characters, "-" and "." in
    the pod name.
    However, there are special rules about how "-" and "." can be used so let's
    only keep
    alphanumeric chars  see here for detail:
    https://kubernetes.io/docs/concepts/overview/working-with-objects/names/

    :param string: The requested Pod name
    :return: Pod name stripped of any unsafe characters
    """
    return ''.join(ch.lower() for ch in list(string) if ch.isalnum())