使用kubeadm工具升级kubernetes

一、背景：

kubeadm部署的kubernetes集群进行升级，通常先升级控制节点，控制节点升级完成后再升级工作节点，本博文只升级了控制节点，工作节点按照相同的流程进行升级即可

环境说明：

主机名	节点
11.0.1.200	k8s客户端操控节点
11.0.1.201	master01
11.0.1.202	node01
11.0.1.203	node02

操作系统：Ubuntu 20.04.6 LTS

升级要求：将控制节点从1.27.0升级到1.27.1，etcd不做升级，从节点不做升级

二、操作流程

1）将控制节点设置为不可调度

kubectl cordon master01

2）驱逐控制节点上的pod

kubectl drain master01 --ignore-daemonsets --force --delete-emptydir-data

3）切换至master01控制节点

ssh master01

#切换到管理员用户，否则加sudo也可以

sudo -i

4）更新网络仓库

apt-get update

5）查看kubeadm可安装版本

root@master01:~# apt-cache madison kubeadm | grep 1.27
kubeadm | 1.27.4-00 | https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial/main amd64 Packages
kubeadm | 1.27.3-00 | https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial/main amd64 Packages
kubeadm | 1.27.2-00 | https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial/main amd64 Packages
kubeadm | 1.27.1-00 | https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial/main amd64 Packages
kubeadm | 1.27.0-00 | https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial/main amd64 Packages

6）安装kubeadm

root@master01:~# apt-get install kubeadm=1.27.1-00

# 验证

root@master01:~# kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.1", GitCommit:"4c9411232e10168d7b050c49a1b59f6df9d7ea4b", GitTreeState:"clean", BuildDate:"2023-04-14T13:20:04Z", GoVersion:"go1.20.3", Compiler:"gc", Platform:"linux/amd64"}

7) 预升级集群

kubeadm upgrade plan v1.27.1

8）升级集群

root@master01:~# kubeadm upgrade apply v1.27.1 --etcd-upgrade=false
[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 -o yaml'
[preflight] Running pre-flight checks.
[upgrade] Running cluster health checks
[upgrade/version] You have chosen to change the cluster version to "v1.27.1"
[upgrade/versions] Cluster version: v1.27.0
[upgrade/versions] kubeadm version: v1.27.1
[upgrade] Are you sure you want to proceed? [y/N]:

注意：升级成功标志