feng-tao closed pull request #2058: [AIRFLOW-850] Add a PythonSensor
URL: https://github.com/apache/incubator-airflow/pull/2058
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diff --git a/airflow/operators/sensors.py b/airflow/operators/sensors.py
index 44a97e00c1..bf02335a95 100644
--- a/airflow/operators/sensors.py
+++ b/airflow/operators/sensors.py
@@ -679,3 +679,57 @@ def poke(self, context):
raise ae
return True
+
+class PythonSensor(BaseSensorOperator):
+ """
+ Waits for a Python callable to return True
+
+ :param python_callable: A reference to an object that is callable
+ :type python_callable: python callable
+ :param op_kwargs: a dictionary of keyword arguments that will get unpacked
+ in your function
+ :type op_kwargs: dict
+ :param op_args: a list of positional arguments that will get unpacked when
+ calling your callable
+ :type op_args: list
+ :param provide_context: if set to true, Airflow will pass a set of
+ keyword arguments that can be used in your function. This set of
+ kwargs correspond exactly to what you can use in your jinja
+ templates. For this to work, you need to define `**kwargs` in your
+ function header.
+ :type provide_context: bool
+ :param templates_dict: a dictionary where the values are templates that
+ will get templated by the Airflow engine sometime between
+ ``__init__`` and ``execute`` takes place and are made available
+ in your callable's context after the template has been applied
+ :type templates_dict: dict of str
+ """
+
+ template_fields = ('templates_dict',)
+ template_ext = tuple()
+
+ def __init__(
+ self,
+ python_callable,
+ op_args=None,
+ op_kwargs=None,
+ provide_context=False,
+ templates_dict=None,
+ *args, **kwargs):
+ super(PythonSensor, self).__init__(*args, **kwargs)
+ self.python_callable = python_callable
+ self.op_args = op_args or []
+ self.op_kwargs = op_kwargs or {}
+ self.provide_context = provide_context
+ self.templates_dict = templates_dict
+
+
+ def poke(self, context):
+ if self.provide_context:
+ context.update(self.op_kwargs)
+ context['templates_dict'] = self.templates_dict
+ self.op_kwargs = context
+
+ logging.info("Poking callable: " + str(self.python_callable))
+ return_value = self.python_callable(*self.op_args, **self.op_kwargs)
+ return bool(return_value)
diff --git a/tests/operators/sensors.py b/tests/operators/sensors.py
index e77216b580..2633e4c41b 100644
--- a/tests/operators/sensors.py
+++ b/tests/operators/sensors.py
@@ -22,7 +22,7 @@
from datetime import datetime, timedelta
from airflow import DAG, configuration
-from airflow.operators.sensors import HttpSensor, BaseSensorOperator,
HdfsSensor
+from airflow.operators.sensors import HttpSensor, BaseSensorOperator,
HdfsSensor, PythonSensor
from airflow.utils.decorators import apply_defaults
from airflow.exceptions import (AirflowException,
AirflowSensorTimeout,
@@ -181,3 +181,38 @@ def test_legacy_file_does_not_exists(self):
# Then
with self.assertRaises(AirflowSensorTimeout):
task.execute(None)
+
+class PythonSensorTests(unittest.TestCase):
+
+ def setUp(self):
+ configuration.load_test_config()
+ args = {
+ 'owner': 'airflow',
+ 'start_date': DEFAULT_DATE
+ }
+ dag = DAG(TEST_DAG_ID, default_args=args)
+ self.dag = dag
+
+ def test_python_sensor_true(self):
+ t = PythonSensor(
+ task_id='python_sensor_check_true',
+ python_callable=lambda: True,
+ dag=self.dag)
+ t.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE,
ignore_ti_state=True)
+
+ def test_python_sensor_false(self):
+ t = PythonSensor(
+ task_id='python_sensor_check_false',
+ timeout=1,
+ python_callable=lambda: False,
+ dag=self.dag)
+ with self.assertRaises(AirflowSensorTimeout):
+ t.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE,
ignore_ti_state=True)
+
+ def test_python_sensor_raise(self):
+ t = PythonSensor(
+ task_id='python_sensor_check_raise',
+ python_callable=lambda: 1/0,
+ dag=self.dag)
+ with self.assertRaises(ZeroDivisionError):
+ t.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE,
ignore_ti_state=True)
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