升级k8s集群必须先升级kubeadm版本到⽬的k8s版本

1、升级准备

在k8s的所有master节点进⾏组件升级，将kube-controller-manager、kube-apiserver、kube-scheduler、kube-proxy进⾏版本升级。

#验证当前版本
root@k8s-master1:~# kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.15", GitCommit:"8f1e5bf0b9729a899b8df86249b56e2c74aebc55", GitTreeState:"clean", BuildDate:"2022-01-19T17:26:37Z", GoVersion:"go1.15.15", Compiler:"gc", Platform:"linux/amd64"}

#验证当前node版本
root@k8s-master1:~# kubectl get node
NAME                      STATUS   ROLES                  AGE   VERSION
k8s-master1.kubeadm.com   Ready    control-plane,master   37h   v1.20.5
k8s-master2.kubeadm.com   Ready    control-plane,master   37h   v1.20.5
k8s-master3.kubeadm.com   Ready    control-plane,master   37h   v1.20.5
k8s-node1.kubeadm.com     Ready    <none>                 37h   v1.20.5
k8s-node2.kubeadm.com     Ready    <none>                 37h   v1.20.5
k8s-node3.kubeadm.com     Ready    <none>                 37h   v1.20.5

2、升级master节点版本

#各master安装指定新版本kubeadm
root@k8s-master1:~# apt-cache madison kubeadm
root@k8s-master1:~# apt-get install kubeadm=1.20.15-00 -y
root@k8s-master2:~# apt-get install kubeadm=1.20.15-00 -y
root@k8s-master3:~# apt-get install kubeadm=1.20.15-00 -y

#验证kubeadm版本
root@k8s-master1:~# kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.6", GitCommit:"8a62859e515889f07e3e3be6a1080413f17cf2c3", GitTreeState:"clean", BuildDate:"2021-04-15T03:26:21Z", GoVersion:"go1.15.10", Compiler:"gc", Platform:"linux/amd64"}

#查看升级计划
root@k8s-master1:~# kubeadm upgrade plan

#执⾏版本升级
#升级前先将需要升级的master节点从Haproxy上踢掉，避免升级过程中有请求转发到该master上
root@k8s-master1:~# kubeadm upgrade apply v1.20.15
root@k8s-master2:~# kubeadm upgrade apply v1.20.15
root@k8s-master3:~# kubeadm upgrade apply v1.20.15

3、升级node节点版本

#验证当前node版本
root@k8s-master1:~# kubectl get node
NAME                      STATUS   ROLES                  AGE   VERSION
k8s-master1.kubeadm.com   Ready    control-plane,master   38h   v1.20.5
k8s-master2.kubeadm.com   Ready    control-plane,master   38h   v1.20.5
k8s-master3.kubeadm.com   Ready    control-plane,master   37h   v1.20.5
k8s-node1.kubeadm.com     Ready    <none>                 37h   v1.20.5
k8s-node2.kubeadm.com     Ready    <none>                 37h   v1.20.5
k8s-node3.kubeadm.com     Ready    <none>                 37h   v1.20.5

各节点升级kubelet二进制包
root@k8s-master1:~# apt install kubelet=1.20.15-00 kubeadm=1.20.15-00
 kubectl=1.20.15-00 -y
root@k8s-master2:~# apt install kubelet=1.20.15-00 kubeadm=1.20.15-00
 kubectl=1.20.15-00 -y
root@k8s-master3:~# apt install kubelet=1.20.15-00 kubeadm=1.20.15-00
 kubectl=1.20.15-00 -y
root@k8s-node1:~# apt install kubelet=1.20.15-00 kubeadm=1.20.15-00
 kubectl=1.20.15-00 -y
root@k8s-node2:~# apt install kubelet=1.20.15-00 kubeadm=1.20.15-00
 kubectl=1.20.15-00 -y
root@k8s-node3:~# apt install kubelet=1.20.15-00 kubeadm=1.20.15-00
 kubectl=1.20.15-00 -y