# Copyright 2018 Google LLC

#

# 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

#

# https://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.

"""An example DAG demonstrating a cyle in the task IDs."""

import datetime

from airflow import models

from airflow.operators import dummy_operator

yesterday = datetime.datetime.now() - datetime.timedelta(days=1)

default_dag_args = {

'start_date': yesterday,

}

with models.DAG(

'composer_sample_cycle',

schedule_interval=datetime.timedelta(days=1),

default_args=default_dag_args) as dag:

start = dummy_operator.DummyOperator(task_id='oops_a_cycle')

end = dummy_operator.DummyOperator(task_id='oops_a_cycle')

start >> end