Goal

At present a VirtualMachine using instance types and/or preferences will have runtime derived data such as the name of a ControllerRevision capturing the state of each resource mutated into the core spec during submission.

This breaks declarative management of VirtualMachines as an owner has no way of pre-populating these runtime derived values and will always see changes made to the spec of their VirtualMachine after submission.

This design proposal aims to enable declarative management of VirtualMachines using instance types and/or preferences by using status to track runtime derived data while retaining all existing behavior and lifecycle support of a VirtualMachine using an instance type and/or preference.

User Stories

• As a VirtualMachine owner I want to declaratively manage my VirtualMachines using instance types and/or preferences
• As a VirtualMachine owner I want existing VirtualMachine lifecycle features to continue to work such as snapshot and restore
• As a VirtualMachine owner I want an easy to use mechanism for switching between instance types and preferences

Non-Requirements

• Deduplication of instance type and preference ControllerRevisions
• A new instancetype API group version to v1beta2, all of the API changes actually land in the core v1 API group.

Notes

• https://github.com/kubevirt/kubevirt/issues/10145
• https://github.com/kubevirt/community/pull/317