docs-archive/apache-airflow/2.3.0/_sources/howto/export-more-env-vars.rst.txt

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Export dynamic environment variables available for operators to use
===================================================================


The key value pairs returned in ``get_airflow_context_vars`` defined in
``airflow_local_settings.py`` are injected to default airflow context environment variables,
which are available as environment variables when running tasks. Note, both key and
value are must be string.

``dag_id``, ``task_id``, ``execution_date``, ``dag_run_id``,
``dag_owner``, ``dag_email`` are reserved keys.


1.  Create ``airflow_local_settings.py`` file and put in on ``$PYTHONPATH`` or
    to ``$AIRFLOW_HOME/config`` folder. (Airflow adds ``$AIRFLOW_HOME/config`` on ``PYTHONPATH`` when
    Airflow is initialized)

2.  Define ``get_airflow_context_vars`` in ``airflow_local_settings.py`` file.


For example:

In your ``airflow_local_settings.py`` file.

.. code-block:: python

  def get_airflow_context_vars(context) -> Dict[str, str]:
      """
      :param context: The context for the task_instance of interest.
      """
      # more env vars
      return {"airflow_cluster": "main"}