Business Context:
ARO HCP runs an E2E test suite in dev, integration, staging, and production environments as part of service validation. Currently, the E2E suite must provision clusters using customer-facing sizing configurations, which results in higher resource consumption and costs. The service team needs the ability to create minimal-sized clusters specifically for E2E testing in all of these environments that would normally be inappropriate for customer use.

Goal:
Enable ARO HCP (and other Hypershift operator consumers) to configure and use cluster sizes for testing purposes that are not exposed to customers, reducing E2E test costs and enabling test execution in resource-constrained environments.

Scope:

In-Scope:

• Ability to define a cluster size configuration in ClusterSizingConfig that is not exposed to customers (or reconciled by the controller) as a valid sizing option
• This "hidden" size should only be reachable by setting the existing override annotation (e.g., hypershift.openshift.io/cluster-size-override)
• Management cluster administrators can define and use this size; customers cannot reach these sizes under any scaling circumstances

Out-of-Scope:

• Changes to customer-facing cluster sizing options or behavior
• Modifications to existing autoscaling or node count sizing logic
• Changes to the override annotation mechanism itself (beyond supporting hidden sizes)

Teams and Stakeholders:

• Hypershift Operator Team (implementation)
• ARO HCP Service Team (consumer/requester)

Success Criteria:

• A cluster size can be defined that does not appear as a valid option for customers
• The hidden size can be successfully applied via the override annotation
• E2E test clusters can be provisioned using the minimal hidden size configuration
• No regression to existing customer-facing sizing functionality

Risks and Assumptions:

• Assumption: The override annotation mechanism will remain the preferred method for admin-only size selection

References: