User Story

As a user i would like the cluster autoscaler to ignore platform specific zone labels when using the balance similar node groups feature, having the cluster autoscaler operator configure these labels for me would solve my issue and reduce deployment complexity.

Background

Based on discussions with the upstream cluster-api community about the future of the cluster-api nodegroupset processor (see OCPCLOUD-1669 for more detail), we will need to ensure that the CAO is adding the proper labels for each platform when deploying the autoscaler.

The labels to be ignored can be found in this PR https://github.com/kubernetes/autoscaler/pull/5148 , and we will need to keep this list updated in the future.

Steps

• add ability for CAO to inject label flags (--balancing-ignore-label)
• add ability for CAO to detect platform
• add feature for CAO to inject label flags based on the platform

Stakeholders

• openshift eng

Definition of Done

• user can specify to deploy autoscaler on a platform and use the balancing feature without needing to specify zone, and similar, labels to ignore

• Docs

• CAO developer docs should be updated, but this should not require a product doc update

• Testing

• balance node group e2e tests are working