incubator-airflow/airflow/example_dags/example_trigger_target_dag.py

64 строки
2.3 KiB
Python

# -*- coding: utf-8 -*-
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from airflow.operators.bash_operator import BashOperator
from airflow.operators.python_operator import PythonOperator
from airflow.models import DAG
from datetime import datetime
import pprint
pp = pprint.PrettyPrinter(indent=4)
# This example illustrates the use of the TriggerDagRunOperator. There are 2
# entities at work in this scenario:
# 1. The Controller DAG - the DAG that conditionally executes the trigger
# (in example_trigger_controller.py)
# 2. The Target DAG - DAG being triggered
#
# This example illustrates the following features :
# 1. A TriggerDagRunOperator that takes:
# a. A python callable that decides whether or not to trigger the Target DAG
# b. An optional params dict passed to the python callable to help in
# evaluating whether or not to trigger the Target DAG
# c. The id (name) of the Target DAG
# d. The python callable can add contextual info to the DagRun created by
# way of adding a Pickleable payload (e.g. dictionary of primitives). This
# state is then made available to the TargetDag
# 2. A Target DAG : c.f. example_trigger_target_dag.py
args = {
'start_date': datetime.utcnow(),
'owner': 'airflow',
}
dag = DAG(
dag_id='example_trigger_target_dag',
default_args=args,
schedule_interval=None)
def run_this_func(ds, **kwargs):
print("Remotely received value of {} for key=message".format(kwargs['dag_run'].conf['message']))
run_this = PythonOperator(
task_id='run_this',
provide_context=True,
python_callable=run_this_func,
dag=dag)
# You can also access the DagRun object in templates
bash_task = BashOperator(
task_id="bash_task",
bash_command='echo "Here is the message: {{ dag_run.conf["message"] if dag_run else "" }}" ',
dag=dag)