k8s安装之node-autoapprove-certificate-server.yaml

kubelet证书分为server和client两种， k8s 1.9默认启用了client证书的自动轮换，但server证书自动轮换需要用户开启。方法是：

2.1 增加 kubelet 参数(现已默认)

--feature-gates=RotateKubeletServerCertificate=true

2.2 增加 controller-manager 参数(现已默认)

--experimental-cluster-signing-duration=87600h0m0s
--feature-gates=RotateKubeletServerCertificate=true

2.3 创建 rbac 对象

创建rbac对象，允许节点轮换kubelet server证书：

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:certificates.k8s.io:certificatesigningrequests:selfnodeserver
rules:
- apiGroups:
  - certificates.k8s.io
  resources:
  - certificatesigningrequests/selfnodeserver
  verbs:
  - create
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kubeadm:node-autoapprove-certificate-server
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:certificates.k8s.io:certificatesigningrequests:selfnodeserver
subjects:
- apiGroup: rbac.authorization.k8s.io
  kind: Group
  name: system:nodes