kubeadm.k8s.io/v1beta3 는 1.31 부터 v1beta4 로 대체됐다 (v1beta3 는 아직 읽히지만 kubeadm config migrate 로 바꾼다). experimental-cluster-signing-duration 플래그는 제거됐고 cluster-signing-duration 이 그 자리다. 2026-09-20 확인. https://kubernetes.io/docs/reference/config-api/kubeadm-config.v1beta4/
cat <<EOF | tee kubeadm-config.yaml
apiVersion: kubeadm.k8s.io/v1beta3
kind: ClusterConfiguration
kubernetesVersion: stable
controlPlaneEndpoint: "192.168.1.1:6443"
networking:
podSubnet: "10.244.0.0/16"
certificatesDir: /etc/kubernetes/pki
---
apiVersion: kubeadm.k8s.io/v1beta3
kind: InitConfiguration
localAPIEndpoint:
advertiseAddress: 192.168.1.1
bindPort: 6443
nodeRegistration:
kubeletExtraArgs:
cgroup-driver: "systemd"
---
apiVersion: kubeadm.k8s.io/v1beta3
kind: ClusterConfiguration
controllerManager:
extraArgs:
experimental-cluster-signing-duration: 876000h # 100 years
EOF
kubeadm init --config=kubeadm-config.yaml --upload-certs