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    to you under the Apache License, Version 2.0 (the
    "License"); you may not use this file except in compliance
    with the License.  You may obtain a copy of the License at

 ..   http://www.apache.org/licenses/LICENSE-2.0

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    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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.. _hashicorp_vault_secrets:

Hashicorp Vault Secrets Backend
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

To enable Hashicorp vault to retrieve Airflow connection/variable, specify :py:class:`~airflow.providers.hashicorp.secrets.vault.VaultBackend`
as the ``backend`` in  ``[secrets]`` section of ``airflow.cfg``.

Here is a sample configuration:

.. code-block:: ini

    [secrets]
    backend = airflow.providers.hashicorp.secrets.vault.VaultBackend
    backend_kwargs = {"connections_path": "connections", "variables_path": "variables", "mount_point": "airflow", "url": "http://127.0.0.1:8200"}

The default KV version engine is ``2``, pass ``kv_engine_version: 1`` in ``backend_kwargs`` if you use
KV Secrets Engine Version ``1``.

You can also set and pass values to Vault client by setting environment variables. All the
environment variables listed at https://www.vaultproject.io/docs/commands/#environment-variables are supported.

Hence, if you set ``VAULT_ADDR`` environment variable like below, you do not need to pass ``url``
key to ``backend_kwargs``:

.. code-block:: bash

    export VAULT_ADDR="http://127.0.0.1:8200"

Optional lookup
"""""""""""""""

Optionally connections, variables, or config may be looked up exclusive of each other or in any combination.
This will prevent requests being sent to Vault for the excluded type.

If you want to look up some and not others in Vault you may do so by setting the relevant ``*_path`` parameter of the ones to be excluded as ``null``.

For example, if you want to set parameter ``connections_path`` to ``"airflow-connections"`` and not look up variables, your configuration file should look like this:

.. code-block:: ini

    [secrets]
    backend = airflow.providers.hashicorp.secrets.vault.VaultBackend
    backend_kwargs = {"connections_path": "airflow-connections", "variables_path": null, "mount_point": "airflow", "url": "http://127.0.0.1:8200"}

Storing and Retrieving Connections
""""""""""""""""""""""""""""""""""

If you have set ``connections_path`` as ``connections`` and ``mount_point`` as ``airflow``, then for a connection id of
``smtp_default``, you would want to store your secret as:

.. code-block:: bash

    vault kv put airflow/connections/smtp_default conn_uri=smtps://user:host@relay.example.com:465

Note that the ``Key`` is ``conn_uri``, ``Value`` is ``postgresql://airflow:airflow@host:5432/airflow`` and
``mount_point`` is ``airflow``.

You can make a ``mount_point`` for ``airflow`` as follows:

.. code-block:: bash

    vault secrets enable -path=airflow -version=2 kv

Verify that you can get the secret from ``vault``:

.. code-block:: console

    ❯ vault kv get airflow/connections/smtp_default
    ====== Metadata ======
    Key              Value
    ---              -----
    created_time     2020-03-19T19:17:51.281721Z
    deletion_time    n/a
    destroyed        false
    version          1

    ====== Data ======
    Key         Value
    ---         -----
    conn_uri    smtps://user:host@relay.example.com:465

The value of the Vault key must be the :ref:`connection URI representation <generating_connection_uri>`
of the connection object to get connection.

Storing and Retrieving Variables
""""""""""""""""""""""""""""""""

If you have set ``variables_path`` as ``variables`` and ``mount_point`` as ``airflow``, then for a variable with
``hello`` as key, you would want to store your secret as:

.. code-block:: bash

    vault kv put airflow/variables/hello value=world

Verify that you can get the secret from ``vault``:

.. code-block:: console

    ❯ vault kv get airflow/variables/hello
    ====== Metadata ======
    Key              Value
    ---              -----
    created_time     2020-03-28T02:10:54.301784Z
    deletion_time    n/a
    destroyed        false
    version          1

    ==== Data ====
    Key      Value
    ---      -----
    value    world

Note that the secret ``Key`` is ``value``, and secret ``Value`` is ``world`` and
``mount_point`` is ``airflow``.