kubeadm upgrade plan报错记
报错如下：
[root@k8s-master1 ~]# kubeadm upgrade plan
[upgrade/config] Making sure the configuration is correct:
[upgrade/config] Reading configuration from the cluster...
[upgrade/config] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[preflight] Running pre-flight checks.
[upgrade] Making sure the cluster is healthy:
[upgrade/health] FATAL: [preflight] Some fatal errors occurred:
[ERROR ControlPlaneNodesReady]: there are NotReady control-planes in the cluster: [k8s-master2]
[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
缘由：没按官网教程来
官网说要在control plane node 安装kubeadm，我不听劝阻，把所有节点的kubelet，kubeadm，kubectl全更新到了v1.17.0，然后就报了这个错误，误操作命令：apt install kubeadm=1.17.0-00 kubelet=1.17.0-00 kubectl=1.17.0-00 -y
解决：恢复旧版本
参考了这篇文章：https://blog.csdn.net/michaeljscofield/article/details/38072955
#所有节点，除了kubeadm包外均恢复1.16.3版本
apt install aptitude -y
aptitude install kubelet=1.16.3-00 kubectl=1.16.3-00 -y
然后就好了：
[root@k8s-master1 ~]# kubeadm upgrade plan
[upgrade/config] Making sure the configuration is correct:
[upgrade/config] Reading configuration from the cluster...
[upgrade/config] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[preflight] Running pre-flight checks.
[upgrade] Making sure the cluster is healthy:
[upgrade] Fetching available versions to upgrade to
[upgrade/versions] Cluster version: v1.16.3
[upgrade/versions] kubeadm version: v1.17.0
[upgrade/versions] Latest stable version: v1.17.0
[upgrade/versions] Latest version in the v1.16 series: v1.16.4
Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':
COMPONENT CURRENT AVAILABLE
Kubelet 3 x v1.16.3 v1.16.4
Upgrade to the latest version in the v1.16 series:
COMPONENT CURRENT AVAILABLE
API Server v1.16.3 v1.16.4
Controller Manager v1.16.3 v1.16.4
Scheduler v1.16.3 v1.16.4
Kube Proxy v1.16.3 v1.16.4
CoreDNS 1.6.2 1.6.5
Etcd 3.3.15 3.3.17-0
You can now apply the upgrade by executing the following command:
kubeadm upgrade apply v1.16.4
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Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':
COMPONENT CURRENT AVAILABLE
Kubelet 3 x v1.16.3 v1.17.0
Upgrade to the latest stable version:
COMPONENT CURRENT AVAILABLE
API Server v1.16.3 v1.17.0
Controller Manager v1.16.3 v1.17.0
Scheduler v1.16.3 v1.17.0
Kube Proxy v1.16.3 v1.17.0
CoreDNS 1.6.2 1.6.5
Etcd 3.3.15 3.4.3-0
You can now apply the upgrade by executing the following command:
kubeadm upgrade apply v1.17.0
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