chart/docs/customizing-workers.rst

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Customizing Workers
===================

Both ``CeleryExecutor`` and ``KubernetesExecutor`` workers can be highly customized with the :ref:`workers parameters <parameters:workers>`.
For example, to set resources on workers for CeleryExecutor:

.. code-block:: yaml
   :caption: values.yaml

   workers:
     celery:
       resources:
         requests:
           cpu: 1
         limits:
           cpu: 1

Custom ``pod_template_file``
----------------------------

With ``KubernetesExecutor`` you can also provide a complete ``pod_template_file``
to fully override default Kubernetes workers configuration. This may be useful if you need different configuration between
worker types for ``KubernetesExecutor`` or if you need to customize something not possible with :ref:`workers parameters <parameters:workers>` alone.

.. note::

   Configuration options between Celery and Kubernetes workers can be overwritten by ``workers.celery`` and ``workers.kubernetes`` sections.

As an example, let's say you want to set ``priorityClassName`` on your workers:

.. note::

   The following example is NOT functional, but meant to be illustrative of how you can provide a custom ``pod_template_file``.
   You're better off starting with the default `pod_template_file`_ instead.

.. _pod_template_file: https://github.com/apache/airflow/blob/main/chart/files/pod-template-file.kubernetes-helm-yaml

.. code-block:: yaml
   :caption: values.yaml

   podTemplate: |
     apiVersion: v1
     kind: Pod
     metadata:
       name: placeholder-name
       labels:
         tier: airflow
         component: worker
         release: {{ .Release.Name }}
     spec:
       priorityClassName: high-priority
       containers:
         - name: base

The same can be achieved with default `pod_template_file`_ by overriding the ``priorityClassName`` option for KubernetesExecutor like:

.. code-block:: yaml
   :caption: values.yaml

   workers:
     kubernetes:
       priorityClassName: high-priority