Airflow no module named for directory in airflow_home directory

Question

I'm working with virtualenv. I i'm trying to use packages inside DAG folders. Current state of airflow_home directory is:

airflow_home/airflow.cfg
airflow_home/airflow.db
airflow_home/dags/__init__.py 
airflow_home/dags/hello_world.py
airflow_home/dags/support/inner.py
airflow_home/dags/support/__init__.py 

hello_world.py has code:

from datetime import datetime
from airflow import DAG
from airflow.operators.dummy_operator import DummyOperator
from airflow.operators.python_operator import PythonOperator
from dags.support import inner


def print_hello():
    return 'Hello world'

dag = DAG('hello_world', description='simple tutorial DAG',
          schedule_interval='0 12 * * *', start_date=datetime(2017, 8, 20), catchup=False)

dummy_operator = DummyOperator(task_id='dummy_task', retries=3, dag=dag)

hello_operator = PythonOperator(task_id='hello_task', python_callable=print_hello, dag=dag)

hello_from_inner_operator = PythonOperator(task_id='hello_from_inner', python_callable=inner.hello_from_inner, dag=dag)

dummy_operator >> hello_operator
hello_operator >> hello_from_inner_operator

If i could manually run this script, it runs. But then i start airflow scheduler,

Broken DAG: No module named 'dags'

error appears. What i'm doing wrong, what is the way to solve this ?

Answer 1

use from support import inner instead.

the path $AIRFLOW_HOME/dags will be added into sys.path when airflow starts. So it will search modules under dags directory.