kubeadm 新增节点

kubeadm 在初始化集群之后会生成加入集群的命令：

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 172.31.40.199:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:768eb1bfeebaf5596c21f9e8f7fa63c0c23e3ea57a9258d65f881a8bbb0f442a

但是该token默认生效时间是一天；
如果之后再增加节点，就需要重新出token
操作如下：

# 通过kubedam重新生成token
[root@master ~]#kubeadm token generate #生成token
7r3l16.5yzfksso5ty2zzie #下面这条命令中会用到该结果
[root@master ~]# kubeadm token create 7r3l16.5yzfksso5ty2zzie  --print-join-command --ttl=0  #根据token输出添加命令
W0604 10:35:00.523781   14568 validation.go:28] Cannot validate kube-proxy config - no validator is available
W0604 10:35:00.523827   14568 validation.go:28] Cannot validate kubelet config - no validator is available
# 生成的加入节点的命令
kubeadm join 192.168.254.100:6443 --token 7r3l16.5yzfksso5ty2zzie     --discovery-token-ca-cert-hash sha256:56281a8be264fa334bb98cac5206aa190527a03180c9f397c253ece41d997e8a