bug: Karpenter 1.0 fails to install using Bottlerocket AMI Family

[JoeNorth]

When trying to install karpenter using BR I found that no default nodeclass was created and the following error was shown:

$ eksdemo install karpenter --replicas 2 -a Bottlerocket -c main-lab
Creating EC2NodeClass "default"
Warning: failed to create resource: EC2NodeClass.karpenter.k8s.aws "default" is invalid: [spec.amiSelectorTerms: Required value, <nil>: Invalid value: "null": some validation rules were not checked because the object was invalid; correct the existing errors to complete validation]

Adding the --dry-run flag shows that the spec.amiSelectorTerms was not specified but this is now required for Karpenter 1.0:

$ eksdemo install karpenter --replicas 2 -a Bottlerocket -c main-lab --dry-run
---
apiVersion: karpenter.k8s.aws/v1
kind: EC2NodeClass
metadata:
  name: default
spec:
  amiFamily: Bottlerocket
  role: KarpenterNodeRole-main-lab
  subnetSelectorTerms:
    - tags:
        Name: eksctl-main-lab-cluster/SubnetPrivate*
  securityGroupSelectorTerms:
    - tags:
        aws:eks:cluster-name: main-lab
  tags:
    eksdemo.io/version: 0.16.0

Doing the same with the AL2 amiFamily shows the following:

$ eksdemo install karpenter --replicas 2 -a AL2 -c main-lab --dry-run
apiVersion: karpenter.k8s.aws/v1
kind: EC2NodeClass
metadata:
  name: default
spec:
  amiFamily: AL2
  role: KarpenterNodeRole-main-lab
  subnetSelectorTerms:
    - tags:
        Name: eksctl-main-lab-cluster/SubnetPrivate*
  securityGroupSelectorTerms:
    - tags:
        aws:eks:cluster-name: main-lab
  tags:
    eksdemo.io/version: 0.16.0
  amiSelectorTerms:
    - id: ami-03413b57906e5c8b2
    - id: ami-0164d2524bf3468bf

Based on the docs[1], it looks like the logic should be updated to use spec.amiSelectorTerms.alias and fetch the version using the appropriate SSM parameter rather than trying to resolve the current AMI IDs.

$ eksdemo version
eksdemo: version.Info{Version:"0.16.0", Date:"2024-08-19T17:41:55Z", Commit:"74fc767"}

[1] - https://karpenter.sh/docs/concepts/nodeclasses/#specamiselectorterms