55 строки
1.5 KiB
Python
55 строки
1.5 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.
|
|
|
|
import airflow
|
|
from airflow.operators.python_operator import BranchPythonOperator
|
|
from airflow.operators.dummy_operator import DummyOperator
|
|
from airflow.models import DAG
|
|
import random
|
|
|
|
|
|
args = {
|
|
'owner': 'airflow',
|
|
'start_date': airflow.utils.dates.days_ago(2)
|
|
}
|
|
|
|
dag = DAG(
|
|
dag_id='example_branch_operator',
|
|
default_args=args,
|
|
schedule_interval="@daily")
|
|
|
|
cmd = 'ls -l'
|
|
run_this_first = DummyOperator(task_id='run_this_first', dag=dag)
|
|
|
|
options = ['branch_a', 'branch_b', 'branch_c', 'branch_d']
|
|
|
|
branching = BranchPythonOperator(
|
|
task_id='branching',
|
|
python_callable=lambda: random.choice(options),
|
|
dag=dag)
|
|
branching.set_upstream(run_this_first)
|
|
|
|
join = DummyOperator(
|
|
task_id='join',
|
|
trigger_rule='one_success',
|
|
dag=dag
|
|
)
|
|
|
|
for option in options:
|
|
t = DummyOperator(task_id=option, dag=dag)
|
|
t.set_upstream(branching)
|
|
dummy_follow = DummyOperator(task_id='follow_' + option, dag=dag)
|
|
t.set_downstream(dummy_follow)
|
|
dummy_follow.set_downstream(join)
|