Time Box: 1 sprint

Adaptable topology is a cluster-topology mode that adjusts cluster control-plane and infrastructure behavior based on the current number of control-plane and worker nodes. The goal of this spike is to update the enhancement proposal with the answers to the following questions.

Research Questions

• Is a ValidatingAdmissionPolicy sufficient to enforce that controlPlaneTopology and infrastructureTopology are always set together?
• Do existing ValidatingAdmissionPolicies need changes to update the Infrastructure config?
• What are the specific designs for library-go utilities that provide topology transition awareness and node-count change subscriptions?

Involved Teams

• OpenShift API Team
• Library Go Reviewers

Acceptance Criteria

• Determine if ValidatingAdmissionPolicy is sufficient for enforcing paired field updates
• Document any required changes to existing ValidatingAdmissionPolicies
• Design library-go utilities for topology transition awareness
• Update enhancement proposal with findings and recommendations

Additional Context

• Enhancement Proposal: https://github.com/openshift/enhancements/pull/1905
• Related to Infrastructure API extensions and library-go shared utilities
• Impacts all operators that need to respond to topology changes