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升级k8s集群使用kubeadm部署kubernetes集群介绍了使用kubeadm快速部署k8s集群，这篇文章将升级k8s集群。
此升级方法仅适用于使用kubeadm部署的k8s集群。
升级kubeadm升级k8s集群必须先升级kubeadm版本到要升级的版本。即要升级kubeadm部署的k8s级群，必须先升级kubeadm版本。
# kubeadm versionkubeadm version: &version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.2", GitCommit:"59603c6e503c87169aea6106f57b9f242f64df89", GitTreeState:"clean", BuildDate:"2020-01-18T23:27:49Z", GoVersion:"go1.13.5", Compiler:"gc", Platform:"linux/amd64"}- 升级kubeadm
# apt-cache madison kubeadm# apt-get install kubeadm=1.17.4-00# kubeadm versionkubeadm version: &version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.4", GitCommit:"8d8aa39598534325ad77120c120a22b3a990b5ea", GitTreeState:"clean", BuildDate:"2020-03-12T21:01:11Z", GoVersion:"go1.13.8", Compiler:"gc", Platform:"linux/amd64"}- 查看升级计划
# 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: v1.17.2[upgrade/versions] kubeadm version: v1.17.4I0723 15:10:34.814329 40861 version.go:251] remote version is much newer: v1.18.6; falling back to: stable-1.17[upgrade/versions] Latest stable version: v1.17.9[upgrade/versions] Latest version in the v1.17 series: v1.17.9Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':COMPONENT CURRENT AVAILABLEKubelet 6 x v1.17.2 v1.17.9Upgrade to the latest version in the v1.17 series:COMPONENT CURRENT AVAILABLEAPI Server v1.17.2 v1.17.9Controller Manager v1.17.2 v1.17.9Scheduler v1.17.2 v1.17.9Kube Proxy v1.17.2 v1.17.9CoreDNS 1.6.5 1.6.5Etcd 3.4.3 3.4.3-0You can now apply the upgrade by executing the following command: kubeadm upgrade apply v1.17.9Note: Before you can perform this upgrade, you have to update kubeadm to v1.17.9.在各个master节点进行升级
master节点要一个一个升级，不要一起同时升级
# kubeadm upgrade apply v1.17.4......[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.17.4". Enjoy![upgrade/kubelet] Now that your control plane is upgraded, please proceed with upgrading your kubelets if you haven't already done so.# docker images|grep v1.17.4registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy v1.17.4 6dec7cfde1e5 4 months ago 116MBregistry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver v1.17.4 2e1ba57fe95a 4 months ago 171MBregistry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager v1.17.4 7f997fcf3e94 4 months ago 161MBregistry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler v1.17.4升级kubelet和kubectl
# apt install kubelet=1.17.4-00 kubectl=1.17.4-00查看当前node 版本
# kubectl get nodeNAME STATUS ROLES AGE VERSIONk8s-master1 Ready master 25h v1.17.4k8s-master2 Ready master 24h v1.17.4k8s-master3 Ready master 24h v1.17.4k8s-node1 Ready <none> 23h v1.17.2k8s-node2 Ready <none> 23h v1.17.2k8s-node3 Ready <none> 23h v1.17.2升级node节点配置文件
# kubeadm upgrade node --kubelet-version 1.17.4[upgrade] Reading configuration from the cluster...[upgrade] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'[upgrade] Skipping phase. Not a control plane node.[upgrade] Using kubelet config version 1.17.4, while kubernetes-version is v1.17.4[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.17" ConfigMap in the kube-system namespace[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"[upgrade] The configuration for this node was successfully updated![upgrade] Now you should go ahead and upgrade the kubelet package using your package manager.升级node节点的kubelet、kubeadm
# apt install kubelet=1.17.4-00 kubeadm=1.17.4-00查看node
# kubectl get nodeNAME STATUS ROLES AGE VERSIONk8s-master1 Ready master 25h v1.17.4k8s-master2 Ready master 24h v1.17.4k8s-master3 Ready master 24h v1.17.4k8s-node1 Ready <none> 24h v1.17.4k8s-node2 Ready <none> 24h v1.17.4k8s-node3 Ready <none> 24h v1.17.4