在Airflow中,可以通过创建一个自定义的Operator类来根据hook的结果返回sensor或DummyOperator。以下是一个示例代码:
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
from airflow.sensors.base_sensor_operator import BaseSensorOperator
from airflow.operators.dummy_operator import DummyOperator
class HookResultOperator(BaseOperator):
"""
Operator that creates a sensor or DummyOperator based on the hook result.
"""
@apply_defaults
def __init__(self, hook, sensor_task_id, dummy_task_id, *args, **kwargs):
super(HookResultOperator, self).__init__(*args, **kwargs)
self.hook = hook
self.sensor_task_id = sensor_task_id
self.dummy_task_id = dummy_task_id
def execute(self, context):
# Call the hook and get the result
result = self.hook.get_result()
if result:
# Create a sensor
sensor_task = BaseSensorOperator(
task_id=self.sensor_task_id,
poke_interval=60, # Set the poke interval as needed
timeout=3600 # Set the timeout as needed
)
sensor_task.execute(context)
else:
# Create a DummyOperator
dummy_task = DummyOperator(task_id=self.dummy_task_id)
dummy_task.execute(context)
在上面的示例中,我们创建了一个名为HookResultOperator
的自定义Operator类。在execute
方法中,我们调用了hook的get_result
方法来获取结果。如果结果为真,则创建一个sensor,并执行它的execute
方法;否则,创建一个DummyOperator并执行它的execute
方法。
请注意,上述示例代码中的hook
是一个虚拟对象,你需要将其替换为实际的hook对象,并确保hook对象有一个get_result
方法返回布尔值结果。
使用示例:
from airflow import DAG
from airflow.hooks.base_hook import BaseHook
from datetime import datetime
from HookResultOperator import HookResultOperator
default_args = {
'owner': 'airflow',
'start_date': datetime(2021, 1, 1)
}
dag = DAG('hook_result_operator_example', default_args=default_args, schedule_interval=None)
hook = BaseHook.get_hook(conn_id='my_hook_conn')
sensor_task_id = 'my_sensor_task'
dummy_task_id = 'my_dummy_task'
task = HookResultOperator(
task_id='hook_result_task',
hook=hook,
sensor_task_id=sensor_task_id,
dummy_task_id=dummy_task_id,
dag=dag
)
在上面的示例中,我们创建了一个HookResultOperator
的实例,并传入了一个实际的hook对象,以及一个sensor和DummyOperator的任务ID。你可以根据需要设置其他参数,如poke_interval
和timeout
等。
请注意,上述示例代码中的conn_id
需要替换为你自己的hook的连接ID。