Which component are you using?:

/area cluster-autoscaler

What version of the component are you using?:

Component version: cluster-autoscaler-1.33.0

What k8s version are you using (kubectl version)?: 1.33

What environment is this in?:

clusterapi, with the cluster-api vsphere provider.

What did you expect to happen?:

scale from zero should work.

What happened instead?:

it did not scale from zero. no new nodes were made.

How to reproduce it (as minimally and precisely as possible):

configure cluster-api provider for CA, then create a MachineDeployment with 0 replicas. add a workload that targets the nodes created by the MachineDeployment.

Anything else we need to know?:

this is happening because of a difference between how a Machine's infrastructureRef field has changed from v1beta1 to v1beta2.

v1beta1 definition uses the core ObjectRef, see https://github.com/kubernetes-sigs/cluster-api/blob/main/api/core/v1beta1/machine_types.go#L396

v1beta2 definition uses an internal type for the reference, see https://github.com/kubernetes-sigs/cluster-api/blob/main/api/core/v1beta2/common_types.go#L361-L387

whereas the current code in CA does not account for this difference, see https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/clusterapi/clusterapi_unstructured.go#L378