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Manage logs
===========

You have a number of options when it comes to managing your Airflow logs.

No persistence
--------------

With this option, Airflow will log locally to each pod. As such, the logs will only be available during the lifetime of the pod.

.. code-block:: bash

   helm upgrade --install airflow apache-airflow/airflow \
     --set logs.persistence.enabled=false

.. note::

   Setting the ``workers.celery.persistence.enabled=false`` is required when ``CeleryExecutor`` is used.

Celery worker log persistence
-----------------------------

If you are using ``CeleryExecutor``, workers persist logs by default to a volume claim created with a ``volumeClaimTemplate``.

You can modify the template:

.. code-block:: bash

   helm upgrade --install airflow apache-airflow/airflow \
     --set executor=CeleryExecutor \
     --set workers.celery.persistence.size=10Gi

.. note::

   With this option only task logs are persisted, unlike when log persistence is enabled which will also persist scheduler logs.

Log persistence enabled
-----------------------

This option will provision a ``PersistentVolumeClaim`` with an access mode of ``ReadWriteMany``. Each component of Airflow will
then log onto the same volume.

Not all volume plugins have support for ``ReadWriteMany`` access mode.
Refer `Persistent Volume Access Modes <https://kubernetes.io/docs/concepts/storage/persistent-volumes/#access-modes>`__
for details.

.. code-block:: bash

   helm upgrade --install airflow apache-airflow/airflow \
     --set logs.persistence.enabled=true
     # You can also override the other persistence
     # by setting the logs.persistence.* values
     # Please refer to values.yaml for details

Externally provisioned PVC
--------------------------

In this approach, Airflow will log to an existing ``ReadWriteMany`` PVC. You pass in the name of the volume claim to the chart
by using the ``logs.persistence.existingClaim`` parameter:

.. code-block:: bash

   helm upgrade --install airflow apache-airflow/airflow \
     --set logs.persistence.enabled=true \
     --set logs.persistence.existingClaim=my-volume-claim

.. note::

   The volume has to be writable by the Airflow user. The easiest way to do this is to ensure GID ``0`` has a write permission.
   More information can be found in the :ref:`Docker image entrypoint documentation <docker-stack:arbitrary-docker-user>`.

Elasticsearch
-------------

If your cluster forwards logs to Elasticsearch, you can configure Airflow to retrieve task logs from it.
See the :doc:`Elasticsearch providers guide <apache-airflow-providers-elasticsearch:logging/index>` for more details.

.. code-block:: bash

   helm upgrade --install airflow apache-airflow/airflow \
     --set elasticsearch.enabled=true \
     --set elasticsearch.secretName=my-es-secret
     # Other choices exist. Please refer to values.yaml for details.