Question

使用气流PythonOperator可以模拟什么内容和位置，例如：

python_callback引发异常，触发on_failure_callback的调用，并且
我可以测试是否调用了该回调，以及使用什么参数？

我尝试在多个地方同时模拟{python_callable}和PythonOperator.execute，但没有成功。

代码文件如下所示：

dags / my_code.py

class CustomException(Exception): pass

def a_callable():
    if OurSqlAlchemyTable.count() == 0:
        raise CustomException("{} is empty".format(OurSqlAlchemyTable.name))
    return True

def a_failure_callable(context):
    SlackWebhookHook(
        http_conn_id=slack_conn_id,
        message= context['exception'].msg,
        channel='#alert-channel'
        ).execute()

dags / a_dag.py

from my_code import a_callable, a_failure_callable

new_task = PythonOperator(
    task_id='new-task', dag=dag-named-sue, conn_id='a_conn_id', timeout=30,
    python_callable=a_callable,
    on_failure_callback=a_failure_callable)

dags / test_a_dag.py

class TestCallback(unittest.TestCase):

    def test_on_failure_callback(self):
        tested_task = DagBag().get_dag('dag-named-sue').get_task('new-task')

        with patch('airflow.operators.python_operator.PythonOperator.execute') as mock_execute:
            with patch('dags.a_dag.a_failure_callable') as mock_callback:
                mock_execute.side_effect = CustomException
                tested_task.execute(context={})

            # does failure of the python_callable trigger the failure callback?
        mock_callback.assert_called()

            # did the exception message make it to the failure callback?
        failure_context = mock_callback.call_args[0]
        self.assertEqual(failure_context['exception'].msg,
                        'OurSqlAlchemyTable is empty')O

测试确实在行CustomException上引起self.task.execute(context={})-但是，在测试代码本身中。我想要的是那个错误在气流代码中引发PythonOperator失败并调用on_failure_callback。

我尝试了任意数量的排列，所有排列都经过测试而没有触发，调用python_callable或找不到要修补的对象：

patch('dags.a_dag.a_callable') as mock_callable
      'a_dag.a_callable'
      'dags.my_code.a_callable'
      'my_code.a_callable'
      'airflow.models.Task.execute'

（{Python3，pytest和mock。）

我在想什么/做错了什么？

（更好的是，我想验证传递给SlackWebhookHook的参数。类似：

with patch('???.SlackWebhookHook.execute') as mock_webhook:
    ... as above ...

kw_dict = mock_webhook.call_args[-1]
assert kw_dict['http_conn_id'] == slack_conn_id
assert kw_dict['message'] == 'OurSqlAlchemyTable is empty'
assert kw_dict['channel'] == '#alert-channel'

（但是我首先关注测试失败回调。）

谢谢。

如何模拟PythonOperator的python_callable和on_failure_callback？

0 个答案: