triggers - Apache Airflow - 完成时触发/安排 DAG 重新运行(文件传感器)

Question

早上好。

我也在尝试设置 DAG

1. 监视/感知文件是否命中网络文件夹
2. 处理文件
3. 归档文件

使用在线教程和 stackoverflow，我已经能够提出以下成功实现目标的 DAG 和 Operator，但是我希望 DAG 在完成后重新安排或重新运行，以便它开始监视/感知另一个文件.

我尝试设置一个变量max_active_runs:1，然后设置一个schedule_interval: timedelta(seconds=5)，这会重新安排DAG，但会开始排队任务并锁定文件.

关于如何在 archive_task 之后重新运行 DAG，有什么想法欢迎吗？

谢谢

DAG 代码

from airflow import DAG
from airflow.operators import PythonOperator, OmegaFileSensor, ArchiveFileOperator
from datetime import datetime, timedelta
from airflow.models import Variable

default_args = {
    'owner': 'glsam',
    'depends_on_past': False,
    'start_date': datetime.now(),
    'provide_context': True,
    'retries': 100,
    'retry_delay': timedelta(seconds=30),
    'max_active_runs': 1,
    'schedule_interval': timedelta(seconds=5),
}

dag = DAG('test_sensing_for_a_file', default_args=default_args)

filepath = Variable.get("soucePath_Test")
filepattern = Variable.get("filePattern_Test")
archivepath = Variable.get("archivePath_Test")

sensor_task = OmegaFileSensor(
    task_id='file_sensor_task',
    filepath=filepath,
    filepattern=filepattern,
    poke_interval=3,
    dag=dag)


def process_file(**context):
    file_to_process = context['task_instance'].xcom_pull(
        key='file_name', task_ids='file_sensor_task')
    file = open(filepath + file_to_process, 'w')
    file.write('This is a test\n')
    file.write('of processing the file')
    file.close()


proccess_task = PythonOperator(
    task_id='process_the_file', 
    python_callable=process_file,
    provide_context=True,
    dag=dag
)

archive_task = ArchiveFileOperator(
    task_id='archive_file',
    filepath=filepath,
    archivepath=archivepath,
    dag=dag)

sensor_task >> proccess_task >> archive_task

文件传感器运算符(operator)

    import os
    import re

    from datetime import datetime
    from airflow.models import BaseOperator
    from airflow.plugins_manager import AirflowPlugin
    from airflow.utils.decorators import apply_defaults
    from airflow.operators.sensors import BaseSensorOperator


    class ArchiveFileOperator(BaseOperator):
        @apply_defaults
        def __init__(self, filepath, archivepath, *args, **kwargs):
            super(ArchiveFileOperator, self).__init__(*args, **kwargs)
            self.filepath = filepath
            self.archivepath = archivepath

        def execute(self, context):
            file_name = context['task_instance'].xcom_pull(
                'file_sensor_task', key='file_name')
            os.rename(self.filepath + file_name, self.archivepath + file_name)


    class OmegaFileSensor(BaseSensorOperator):
        @apply_defaults
        def __init__(self, filepath, filepattern, *args, **kwargs):
            super(OmegaFileSensor, self).__init__(*args, **kwargs)
            self.filepath = filepath
            self.filepattern = filepattern

        def poke(self, context):
            full_path = self.filepath
            file_pattern = re.compile(self.filepattern)

            directory = os.listdir(full_path)

            for files in directory:
                if re.match(file_pattern, files):
                    context['task_instance'].xcom_push('file_name', files)
                    return True
            return False


    class OmegaPlugin(AirflowPlugin):
        name = "omega_plugin"
        operators = [OmegaFileSensor, ArchiveFileOperator]

Answer 1

德米特里斯方法非常有效。

我还在阅读设置中发现 schedule_interval=None 然后使用 TriggerDagRunOperator 也同样有效

trigger = TriggerDagRunOperator(
    task_id='trigger_dag_RBCPV99_rerun',
    trigger_dag_id="RBCPV99_v2",
    dag=dag)

sensor_task >> proccess_task >> archive_task >> trigger