This patch set is meant to create a workflow that will allow us
to upgrade the airflow worker without causing disruption to the
current running workflow.
Note that we will set the update strategy for airflow worker
to 'OnDelete'. The 'OnDelete' update strategy implements the legacy
(1.6 and prior) behavior. When we select this update strategy, the
statefulSet controller will not automatically update Pods when a
modification is made to the StatefulSet’s '.spec.template field'.
This strategy can be selected by setting the '.spec.template.updateStrategy.type'
to 'OnDelete'. Refer to [0] for more information.
[0] https://kubernetes.io/docs/tutorials/stateful-application/basic-stateful-set/#creating-a-statefulset
Change-Id: I1f6c3564b7fba6abe422b86e36818eb2cd3454ea
7219519135