Update aws cluster with secondary control plane load balancer crashes capa controller manager

[alexeysofin]

/kind bug

What steps did you take and what happened:
When updating AWSCluster with

secondaryControlPlaneLoadBalancer:
  name: internal-apiserver
  scheme: internal

which didn't have it previously, capa controller manager crashes with

2024/12/10 17:53:00 http: panic serving 10.244.0.1:15292: runtime error: invalid memory address or nil pointer dereference
goroutine 47708 [running]:
sigs.k8s.io/cluster-api-provider-aws/v2/api/v1beta2.(*AWSCluster).validateControlPlaneLoadBalancerUpdate(0xc0020442d0?, 0x0, 0xc000913a40)
	/workspace/api/v1beta2/awscluster_webhook.go:188 +0x2c2

What did you expect to happen:

A new secondary load balancer is added successfully.

Note

Btw is there any documentation on how to make use of a secondary load balancer, e.g. so that kubelets use it for communication with api-server?

Environment:

• Cluster-api-provider-aws version: v2.7.1
• Kubernetes version: (use kubectl version): v1.30.5
• OS (e.g. from /etc/os-release): ubuntu linux 22.04

[k8s-ci-robot]

This issue is currently awaiting triage.

If CAPA/CAPI contributors determines this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

The triage/accepted label can be added by org members by writing /triage accepted in a comment.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.