服务器重启后怎么加入节点

Question

问题描述：
1、由于服务器重启后，我将Node2加入节点，kubectl get nodes结果如下：node1的状态变为了NotReady；
[root@node1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
master Ready master 2d2h v1.19.3
node1 NotReady 31h v1.19.3
node2 Ready 16m v1.19.3

2、然后我重启node1的docker和kubelet，发现kebelet的状态是loaded；
[root@node1 ~]# systemctl start docker && systemctl start kubelet
[root@node1 ~]# systemctl status kubelet
● kubelet.service - kubelet: The Kubernetes Node Agent
Loaded: loaded (/usr/lib/systemd/system/kubelet.service; enabled; vendor preset: disabled)
Drop-In: /usr/lib/systemd/system/kubelet.service.d
└─10-kubeadm.conf
Active: active (running) since Mon 2022-08-15 00:57:14 CST; 109ms ago
Docs: https://kubernetes.io/docs/
Main PID: 37175 (kubelet)
Tasks: 7
Memory: 17.3M
CGroup: /system.slice/kubelet.service
└─37175 /usr/bin/kubelet --bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf --config=/var/lib/kubelet/config.yaml --networ…

Aug 15 00:57:14 node1 systemd[1]: Started kubelet: The Kubernetes Node Agent.
Aug 15 00:57:14 node1 kubelet[37175]: I0815 00:57:14.971612 37175 server.go:411] Version: v1.19.3
Aug 15 00:57:14 node1 kubelet[37175]: I0815 00:57:14.971826 37175 server.go:831] Client rotation is on, will bootstrap in background
Aug 15 00:57:14 node1 kubelet[37175]: I0815 00:57:14.979889 37175 certificate_store.go:130] Loading cert/key pair from “/var/lib/kubelet/pki/kubelet-client-current.pem”.
Aug 15 00:57:14 node1 kubelet[37175]: I0815 00:57:14.982702 37175 dynamic_cafile_content.go:167] Starting client-ca-bundle::/etc/kubernetes/pki/ca.crt

3、我搜索了一下，说是需要关闭swap，我执行
[root@node1 ~]# journalctl -xefu kubelet ## 查看kubelet日志。
[root@node1 ~]# swapoff -a ## 关闭swap
结果竟然可以启动了，但是还是没有加入集群节点；

4、我就在node1节点，再次执行如下命令，还是不行，报错如下：/etc/kubernetes/kubelet.conf already exists

[root@node1 ~]# kubeadm join 192.168.31.162:6443 --token jhltn4.yk9lmi0fwzc4t7wm --discovery-token-ca-cert-hash sha256:b5c7c6dc495966df7d3191e0acd2cf1c8de0febffcbc9ea5ec50c2fc80422fbb
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected “cgroupfs” as the Docker cgroup driver. The recommended driver is “systemd”. Please follow the guide at https://kubernetes.io/docs/setup/cri/
error execution phase preflight: [preflight] Some fatal errors occurred:
[ERROR FileAvailable–etc-kubernetes-kubelet.conf]: /etc/kubernetes/kubelet.conf already exists
[ERROR FileAvailable–etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists
[preflight] If you know what you are doing, you can make a check non-fatal with --ignore-preflight-errors=...
To see the stack trace of this error execute with --v=5 or higher

希望老师解答一下：
1、如果服务器重启后是不是需要重新加入集群节点？具体该怎么做。
2、如果master执行： kubeadm token create --print-join-command命令，通过生成的token，两个work节点可以共用吗，还是需要分别生成不同的token。

Answer 1

清风 2022-08-14 17:13:38

提示错误etc/kubernetes/kubelet.conf already exists，需要删除这个文件，或者kubeadm reset.

节点重启后要看下flannel 是否起来，没有的话需要kube apply flanne.yml

• 提问者 八卦一百二十八掌 #1

  [root@node1 ~]# rm -f /etc/kubernetes/kubelet.conf
  
  [root@node1 ~]# rm -f /etc/kubernetes/pki/ca.crt
  
  [root@node1 ~]# kubeadm join 192.168.31.162:6443 --token jhltn4.yk9lmi0fwzc4t7wm     --discovery-token-ca-cert-hash sha256:b5c7c6dc495966df7d3191e0acd2cf1c8de0febffcbc9ea5ec50c2fc80422fbb
  [root@node1 ~]# kubectl get nodes
  NAME     STATUS   ROLES    AGE    VERSION
  master   Ready    master   2d2h   v1.19.3
  node1    Ready    <none>   31h    v1.19.3
  node2    Ready    <none>   30m    v1.19.3
  
  这样操作就可以了，对不对。