# 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 use of variables and how to test it."""

import datetime

from airflow import models

from airflow.operators import bash

from airflow.operators import dummy

# If you are running Airflow in more than one time zone

# see https://airflow.apache.org/docs/apache-airflow/stable/timezone.html

# for best practices

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

default_dag_args = {

"start_date": yesterday,

}

with models.DAG(

"composer_sample_variables",

schedule_interval=datetime.timedelta(days=1),

default_args=default_dag_args,

) as dag:

start = dummy.DummyOperator(task_id="start")

end = dummy.DummyOperator(task_id="end")

variable_example = bash.BashOperator(

task_id="variable_example",

bash_command="echo project_id=" + "{{var.value.gcp_project}}",

)

start >> variable_example >> end