docs-archive/apache-airflow/2.2.5/_sources/security/secrets/secrets-backend/index.rst.txt

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Secrets Backend
---------------

.. versionadded:: 1.10.10

In addition to retrieving connections & variables from environment variables or the metastore database, you
can also enable alternative secrets backend to retrieve Airflow connections or Airflow variables via
:ref:`Apache Airflow Community provided backends <community_secret_backends>` in
:doc:`apache-airflow-providers:core-extensions/secrets-backends`.

.. note::

    The Airflow UI only shows connections and variables stored in the Metadata DB and not via any other method.
    If you use an alternative secrets backend, check inside your backend to view the values of your variables and connections.

You can also get Airflow configurations with sensitive data from the Secrets Backend.
See :doc:`../../../howto/set-config` for more details.

Search path
^^^^^^^^^^^
When looking up a connection/variable, by default Airflow will search environment variables first and metastore
database second.

If you enable an alternative secrets backend, it will be searched first, followed by environment variables,
then metastore.  This search ordering is not configurable.

.. warning::

    When using environment variables or an alternative secrets backend to store secrets or variables, it is possible to create key collisions.
    In the event of a duplicated key between backends, all write operations will update the value in the metastore, but all read operations will
    return the first match for the requested key starting with the custom backend, then the environment variables and finally the metastore.

.. _secrets_backend_configuration:

Configuration
^^^^^^^^^^^^^

The ``[secrets]`` section has the following options:

.. code-block:: ini

    [secrets]
    backend =
    backend_kwargs =

Set ``backend`` to the fully qualified class name of the backend you want to enable.

You can provide ``backend_kwargs`` with json and it will be passed as kwargs to the ``__init__`` method of
your secrets backend.

If you want to check which secret backend is currently set, you can use ``airflow config get-value secrets backend`` command as in
the example below.

.. code-block:: bash

    $ airflow config get-value secrets backend
    airflow.providers.google.cloud.secrets.secret_manager.CloudSecretManagerBackend

Supported core backends
^^^^^^^^^^^^^^^^^^^^^^^

.. toctree::
    :maxdepth: 1
    :glob:

    *

.. _community_secret_backends:

Apache Airflow Community provided secret backends
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Apache Airflow Community also releases community developed providers (:doc:`apache-airflow-providers:index`)
and some of them also provide handlers that extend secret backends
capability of Apache Airflow. You can see all those providers in
:doc:`apache-airflow-providers:core-extensions/secrets-backends`.


.. _roll_your_own_secrets_backend:

Roll your own secrets backend
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

A secrets backend is a subclass of :py:class:`airflow.secrets.BaseSecretsBackend` and must implement either
:py:meth:`~airflow.secrets.BaseSecretsBackend.get_connection` or :py:meth:`~airflow.secrets.BaseSecretsBackend.get_conn_uri`.

After writing your backend class, provide the fully qualified class name in the ``backend`` key in the ``[secrets]``
section of ``airflow.cfg``.

Additional arguments to your SecretsBackend can be configured in ``airflow.cfg`` by supplying a JSON string to ``backend_kwargs``, which will be passed to the ``__init__`` of your SecretsBackend.
See :ref:`Configuration <secrets_backend_configuration>` for more details, and :ref:`SSM Parameter Store <ssm_parameter_store_secrets>` for an example.

.. note::

    If you are rolling your own secrets backend, you don't strictly need to use airflow's URI format. But
    doing so makes it easier to switch between environment variables, the metastore, and your secrets backend.

Adapt to non-Airflow compatible secret formats for connections
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The default implementation of Secret backend requires use of an Airflow-specific format of storing
secrets for connections. Currently most community provided implementations require the connections to
be stored as URIs (with the possibility of adding more friendly formats in the future)
:doc:`apache-airflow-providers:core-extensions/secrets-backends`. However some organizations may prefer
to keep the credentials (passwords/tokens etc) in other formats --
for example when you want the same credentials to be used across multiple clients, or when you want to
use built-in mechanism of rotating the credentials that do not work well with the Airflow-specific format.
In this case you will need to roll your own secret backend as described in the previous chapter,
possibly extending existing secret backend and adapt it to the scheme used by your organization.