kubeadm doesn't accept controlplane certificatekey in config file - kubernetes

Question

used version:
kubeadm version: &version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.6", GitCommit:"dff82dc0de47299ab66c83c626e08b245ab19037", GitTreeState:"clean", BuildDate:"2020-07-15T16:56:34Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}
To join a new master node to the controlplane using another registry than the public one to download I need to use kubeadm with a "--configfile " parameter command line. I loaded the k8s container images to my registry and tried to use kubeadm accordingly. Unfortunatley in this case kubeadm doesn't accept the "certificatekey" from the config file.
kubeadm join my-k8s-api.de:443 --config kubeadm-join-config.yaml
the config file looks like that:
---
apiVersion: kubeadm.k8s.io/v1beta1
kind: JoinConfiguration
discovery:
bootstrapToken:
apiServerEndpoint: "my-k8s-api.de:443"
caCertHashes:
- "sha256:9a5687aed5397958ebbca1c421ec56356dc4a5394f6846a64b071d56b3b41a7a"
token: "4bh3s7.adon04r87zyh7gwj"
nodeRegistration:
kubeletExtraArgs:
# pause container image
pod-infra-container-image: my-registry.de:5000/pause:3.1
controlPlane:
certificateKey: "eb3abd79fb011ced254f2c834079d0fa2af62718f6b4750a1e5309c36ed40383"```
actually I get back:
W1204 12:47:12.944020 54671 strict.go:54] error unmarshaling configuration schema.GroupVersionKind{Group:"kubeadm.k8s.io", Version:"v1beta1", Kind:"JoinConfiguration"}: error unmarshaling JSON: while decoding JSON: json: unknown field "certificateKey"
when I use "kubeadm --control-plane --certificate-key XXXXXXXXX" I can successfully join the master node to the controlplane but that needs the node to have internet access.
any guess?
did I a typo?

Answer 1

You are having this error because you are using apiVersion : kubeadm.k8s.io/v1beta1 which don't have this kind of field. I have find out that when I was going thru the v1beta1 docs. You can have a look yourself more details: v1beta1
So what you need to do is switch your apiVersion to:
apiVersion: kubeadm.k8s.io/v1beta2
Which have that required filed type. For details please check v1beta2