airflow "python operator" writes files to different locations - airflow

Question

I have created a python_scripts/ folder under my dags/ folder.
I have 2 different dags running the same python_operator - calling to 2 different python scripts located in the python_scripts/ folder.
They both write output files BUT:
one of them creates the file under the dags/ folder, and one of them creates it in the plugins/ folder.
How does Airflow determine the working path?
How can I get Airflow to write all outputs to the same folder?

Answer 1

One thing you could try, that I use in my dags, would be to set you working path by adding os.chdir('some/path') in your DAG.
This only works if you do not put it into an operator, as those are run in subprocesses and therefore do not change the working path of the parent process.
The other solution I could think of would be using absolute paths when specifying your output.
For the approach with os.chdir try the following and you should see both files get created in the folder defined with path='/home/chr/test/':
from datetime import datetime
import os
import logging
from airflow import DAG
from airflow.exceptions import AirflowException
from airflow.operators.python_operator import PythonOperator
log = logging.getLogger(__name__)
default_args = {
'owner': 'admin',
'depends_on_past': False,
'retries': 0
}
dag = DAG('test_dag',
description='Test DAG',
catchup=False,
schedule_interval='0 0 * * *',
default_args=default_args,
start_date=datetime(2018, 8, 8))
path = '/home/chr/test'
if os.path.isdir(path):
os.chdir(path)
else:
os.mkdir(path)
os.chdir(path)
def write_some_file():
try:
with open("/home/chr/test/absolute_testfile.txt", "wt") as fout:
fout.write('test1\n')
with open("relative_testfile.txt", "wt") as fout:
fout.write('test2\n')
except Exception as e:
log.error(e)
raise AirflowException(e)
write_file_task = PythonOperator(
task_id='write_some_file',
python_callable=write_some_file,
dag=dag
)
Also, please try to provide code next time you ask a question, as it is almost impossible to find out what the problem is, just by reading your question.