Background

This is the second half of OCPCLOUD-2641. This is the implementation for the MachineSet part, which needs to be completed after a test suite to test VAPs against MachineSets is written.
To prevent concurrent reconciles, we will need to validate creation requests for Machine API MachineSets.

In particular, if a Machine API resource is created, and there already exists a Cluster API equivalent resource:

• The MAPI resource may only be create when it is not authoritative

Determine if we can leverage ValidatingAdmissionPolicy for this use case, given we need information from a different resource. If we cannot use VAP, a webhook validation must be created for this.

Behaviours

• If CAPI resource exists
  • Only allow creation of MAPI resource if spec.authoritativeAPI == ClusterAPI

Steps

• Determine if we can use VAP
• If we cannot use VAP, ensure or build out webhook for the use case.
• Implement behaviours for MAPI creation as per above description.

Stakeholders

• Cluster Infra

Definition of Done

• When creating a MAPI resource that has an equivalent CAPI resource, above rules on pausing are observed

• Docs

• <Add docs requirements for this card>

• Testing

• <Explain testing that will be added>