def failover_limitation(self) -> Optional[str]:
        """Returns reason why this node can't promote or None if everything is ok."""
        if not self.reachable:
            return 'not reachable'
        if self.nofailover:
            return 'not allowed to promote'
        if self.watchdog_failed:
            return 'not watchdog capable'
        return None
Returns reason why this node can't promote or None if everything is ok.
patroni/ha.py