def setUp(self):
        super(SimpleInstanceTest, self).setUp()
        db_info = DBInstance(
            InstanceTasks.BUILDING, name="TestInstance")
        self.instance = SimpleInstance(
            None, db_info, InstanceServiceStatus(
                ServiceStatuses.BUILDING), ds_version=Mock(), ds=Mock())
        db_info.addresses = {"private": [{"addr": "123.123.123.123"}],
                             "internal": [{"addr": "10.123.123.123"}],
                             "public": [{"addr": "15.123.123.123"}]}
        self.orig_conf = CONF.network_label_regex
        self.orig_ip_regex = CONF.ip_regex
        self.orig_black_list_regex = CONF.black_list_regex
def trapped_signals(cls, new_signal_handler):
        """A contextmanager which temporarily overrides signal handling.

        NB: This method calls signal.signal(), which will crash if not called from the main thread!
        """
        previous_signal_handler = cls.reset_signal_handler(new_signal_handler)
        try:
            yield
        finally:
            cls.reset_signal_handler(previous_signal_handler)