def get_concurrency_check(self, task_id=dn.CONCURRENCY_CHECK):
"""Generate the concurrency check step
Concurrency check prevents simultaneous execution of dags that should
not execute together.
"""
return ConcurrencyCheckOperator(
task_id=task_id,
on_failure_callback=step_failure_handler,
dag=self.dag)
def dag_concurrency_check(parent_dag_name, child_dag_name, args):
'''
dag_concurrency_check is a sub-DAG that will will allow for a DAG to
determine if it is already running, and result in an error if so.
'''
dag = DAG(
'{}.{}'.format(parent_dag_name, child_dag_name),
default_args=args,
)
dag_concurrency_check_operator = ConcurrencyCheckOperator(
task_id='dag_concurrency_check', dag=dag)
return dag
Operators
"""
def xcom_push(**kwargs):
# Pushes action XCom
kwargs['ti'].xcom_push(key='action',
value=kwargs['dag_run'].conf['action'])
action_xcom = PythonOperator(task_id='action_xcom',
dag=dag,
python_callable=xcom_push)
concurrency_check = ConcurrencyCheckOperator(
task_id=DAG_CONCURRENCY_CHECK_DAG_NAME,
on_failure_callback=failure_handlers.step_failure_handler,
dag=dag)
get_design_version = SubDagOperator(
subdag=get_design_deckhand(PARENT_DAG_NAME,
DECKHAND_GET_DESIGN_VERSION,
args=default_args),
task_id=DECKHAND_GET_DESIGN_VERSION,
on_failure_callback=failure_handlers.step_failure_handler,
dag=dag)
validate_site_design = SubDagOperator(
subdag=validate_site_design(PARENT_DAG_NAME,
VALIDATE_SITE_DESIGN_DAG_NAME,
args=default_args),
task_id=VALIDATE_SITE_DESIGN_DAG_NAME,