docs-archive/1.10.4/_sources/howto/set-config.rst.txt

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Setting Configuration Options
=============================

The first time you run Airflow, it will create a file called ``airflow.cfg`` in
your ``$AIRFLOW_HOME`` directory (``~/airflow`` by default). This file contains Airflow's configuration and you
can edit it to change any of the settings. You can also set options with environment variables by using this format:
``$AIRFLOW__{SECTION}__{KEY}`` (note the double underscores).

For example, the
metadata database connection string can either be set in ``airflow.cfg`` like this:

.. code-block:: bash

    [core]
    sql_alchemy_conn = my_conn_string

or by creating a corresponding environment variable:

.. code-block:: bash

    AIRFLOW__CORE__SQL_ALCHEMY_CONN=my_conn_string

You can also derive the connection string at run time by appending ``_cmd`` to
the key like this:

.. code-block:: bash

    [core]
    sql_alchemy_conn_cmd = bash_command_to_run

The following config options support this ``_cmd`` version:

* ``sql_alchemy_conn`` in ``[core]`` section
* ``fernet_key`` in ``[core]`` section
* ``broker_url`` in ``[celery]`` section
* ``result_backend`` in ``[celery]`` section
* ``password`` in ``[atlas]`` section
* ``smtp_password`` in ``[smtp]`` section
* ``bind_password`` in ``[ldap]`` section
* ``git_password`` in ``[kubernetes]`` section

The idea behind this is to not store passwords on boxes in plain text files.

The universal order of precedence for all configuration options is as follows:

#. set as an environment variable
#. set in ``airflow.cfg``
#. command in ``airflow.cfg``
#. Airflow's built in defaults