Merge kubekey-k3s with cluster-api-k3s

[nasusoba]

Your current KubeKey version

No response

Describe this feature

Hi, I am from cluster-api-k3s. I am seeing that there is a duplicated k3s cluster api, kubekey-k3s. Previously, there was a discussion about merging the two CAPIs here, and I would love to spend some time to see if a merge is possible.

The main reason for a merge is to

• avoid dupliacted feature work or bug fix,
  • e.g., we have been working on management cluster communication with workload cluster etcd, and I believe this is also useful for kubekey
• have a joint effort to make cluster api k3s more stable!

I have also add an issue in cluster-api-k3s repo.

Describe the solution you'd like

Plan in my mind:

1. Understand diff between kubekey-k3s and cluster-api k3s.
   (==> if possible to merge)
2. Contribute the code from kubekey-k3s back to cluster-api k3s.
3. Integrate with kubekey test to verify moving to cluster-api k3s does not break anything.
4. Deprecate kubekey-k3s.

Additional information

cluster-api-k3s has now supported airgapped install. So one diff could be resolved. Could someone help me understand if there is other diff? Thanks so much! : )