tests/dags/test_on_kill.py

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import time

from airflow.models import DAG
from airflow.operators.dummy import DummyOperator
from airflow.utils.timezone import datetime


class DummyWithOnKill(DummyOperator):
    def execute(self, context):
        import os

        # This runs extra processes, so that we can be sure that we correctly
        # tidy up all processes launched by a task when killing
        if not os.fork():
            os.system('sleep 10')
        time.sleep(10)

    def on_kill(self):
        self.log.info("Executing on_kill")
        with open("/tmp/airflow_on_kill", "w") as f:
            f.write("ON_KILL_TEST")


# DAG tests backfill with pooled tasks
# Previously backfill would queue the task but never run it
dag1 = DAG(dag_id='test_on_kill', start_date=datetime(2015, 1, 1))
dag1_task1 = DummyWithOnKill(task_id='task1', dag=dag1, owner='airflow')