airflow-dag-no-schedule-argument (AIR002)

Added in 0.13.0 · Related issues · View source

Derived from the Airflow linter.

What it does

Checks for a DAG() class or @dag() decorator without an explicit schedule (or schedule_interval for Airflow 1) parameter.

The default value of the schedule parameter on Airflow 2 and schedule_interval on Airflow 1 is timedelta(days=1), which is almost never what a user is looking for. Airflow 3 changed the default value to None, and would break existing dags using the implicit default.

If your dag does not have an explicit schedule / schedule_interval argument, Airflow 2 schedules a run for it every day (at the time determined by start_date). Such a dag will no longer be scheduled on Airflow 3 at all, without any exceptions or other messages visible to the user.

Example

from airflow import DAG


# Using the implicit default schedule.
dag = DAG(dag_id="my_dag")

Use instead:

from datetime import timedelta

from airflow import DAG


dag = DAG(dag_id="my_dag", schedule=timedelta(days=1))

airflow-dag-no-schedule-argument (AIR002)

What it does

Why is this bad?

Example