如何对kubernetes进行离线升级和在线升级

本文以kubernetes文件为例，为大家分析kubernetes进行离线升级和在线升级的方法步骤。阅读完整文相信大家对kubernetes升级更新有了一定的认识。

1. kubernetes升级概述

kubernetes版本升级迭代非常快，每三个月更新一个版本,很多新的功能在新版本中快速迭代，为了与社区版本功能保持一致，升级kubernetes集群，社区已通过kubeadm工具统一升级集群，升级步骤简单易行。首先来看下升级kubernetes集群需要升级那些组件：

• 升级管理节点，管理节点上的kube-apiserver，kuber-controller-manager，kube-scheduler，etcd等；
• 其他管理节点，管理节点如果以高可用的方式部署，多个高可用节点需要一并升级；

• worker工作节点，升级工作节点上的Container Runtime如docker，kubelet和kube-proxy。

  版本升级通常分为两类：小版本升级和跨版本升级，小版本升级如1.14.1升级只1.14.2，小版本之间可以跨版本升级如1.14.1直接升级至1.14.3；跨版本升级指大版本升级，如1.14.x升级至1.15.x。本文以离线的方式将1.14.1升级至1.1.5.1版本，升级前需要满足条件如下：

• 当前集群版本需要大于1.14.x，可升级至1.14.x和1.15.x版本，小版本和跨版本之间升级；
• 关闭swap空间；
• 备份数据，将etcd数据备份，以及一些重要目录如/etc/kubernetes,/var/lib/kubelet；
• 升级过程中pod需要重启，确保应用使用RollingUpdate滚动升级策略，避免业务有影响。

2. 离线升级至1.15.1

2.1 升级前准备工作

1、查看当前版本,系统上部署的版本是1.1.4.1

[root@node-1 ~]# kubectl versionClient Version: version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.1", GitCommit:"b7394102d6ef778017f2ca4046abbaa23b88c290", GitTreeState:"clean", BuildDate:"2019-04-08T17:11:31Z", GoVersion:"go1.12.1", Compiler:"gc", Platform:"linux/amd64"}Server Version: version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.1", GitCommit:"b7394102d6ef778017f2ca4046abbaa23b88c290", GitTreeState:"clean", BuildDate:"2019-04-08T17:02:58Z", GoVersion:"go1.12.1", Compiler:"gc", Platform:"linux/amd64"}[root@node-1 ~]# kubeadm versionkubeadm version: &version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.1", GitCommit:"b7394102d6ef778017f2ca4046abbaa23b88c290", GitTreeState:"clean", BuildDate:"2019-04-08T17:08:49Z", GoVersion:"go1.12.1", Compiler:"gc", Platform:"linux/amd64"}

2、查看node节点的版本,node上的kubelet和kube-proxy使用1.1.4.1版本

[root@node-1 ~]# kubectl get nodesNAME     STATUS   ROLES    AGE   VERSIONnode-1   Ready    master   25h   v1.14.1node-2   Ready       25h   v1.14.1node-3   Ready       25h   v1.14.1

3、其他组件状态，确保当前组件，应用状态正常

[root@node-1 ~]# kubectl get componentstatuses NAME                 STATUS    MESSAGE             ERRORscheduler            Healthy   ok                  controller-manager   Healthy   ok                  etcd-0               Healthy   {"health":"true"}   [root@node-1 ~]# [root@node-1 ~]# kubectl get deployments --all-namespaces NAMESPACE     NAME      READY   UP-TO-DATE   AVAILABLE   AGEdefault       demo      3/3     3            3           37mkube-system   coredns   2/2     2            2           25h

4、查看kubernetes最新版本（配置kubernetes的yum源，需要合理上网才可以访问），使用yum list --showduplicates kubeadm --disableexcludes=kubernetes查看当前能升级版本，绿色为当前版本，蓝色为可以升级的版本，如下图：

2.2 升级master节点

1、倒入安装镜像，先从https://pan.baidu.com/s/1hw8Q0Vf3xvhKoEiVtMi6SA网盘中下载kubernetes安装镜像并上传到集群中，解压并进入到v1.15.1目录下，将镜像倒入到三个节点中,以node-2为例倒入镜像：

倒入镜像：[root@node-2 v1.15.1]# docker image load -i kube-apiserver\:v1.15.1.tar [root@node-2 v1.15.1]# docker image load -i kube-scheduler\:v1.15.1.tar [root@node-2 v1.15.1]# docker image load -i kube-controller-manager\:v1.15.1.tar [root@node-2 v1.15.1]# docker image load -i kube-proxy\:v1.15.1.tar 查看当前系统导入镜像列表：[root@node-1 ~]# docker image list REPOSITORY                           TAG                 IMAGE ID            CREATED             SIZEk8s.gcr.io/kube-proxy                v1.15.1             89a062da739d        8 weeks ago         82.4MBk8s.gcr.io/kube-controller-manager   v1.15.1             d75082f1d121        8 weeks ago         159MBk8s.gcr.io/kube-scheduler            v1.15.1             b0b3c4c404da        8 weeks ago         81.1MBk8s.gcr.io/kube-apiserver            v1.15.1             68c3eb07bfc3        8 weeks ago         207MBk8s.gcr.io/kube-proxy                v1.14.1             20a2d7035165        5 months ago        82.1MBk8s.gcr.io/kube-apiserver            v1.14.1             cfaa4ad74c37        5 months ago        210MBk8s.gcr.io/kube-scheduler            v1.14.1             8931473d5bdb        5 months ago        81.6MBk8s.gcr.io/kube-controller-manager   v1.14.1             efb3887b411d        5 months ago        158MBquay.io/coreos/flannel               v0.11.0-amd64       ff281650a721        7 months ago        52.6MBk8s.gcr.io/coredns                   1.3.1               eb516548c180        8 months ago        40.3MBk8s.gcr.io/etcd                      3.3.10              2c4adeb21b4f        9 months ago        258MBk8s.gcr.io/pause                     3.1                 da86e6ba6ca1        21 months ago       742kB

2、更新kubeadm版本至1.15.1，国内可以参考https://blog.51cto.com/2157217/1983992设置kubernetes源

3、校验kubeadm版本,已升级至1.1.5.1版本

[root@node-1 ~]# kubeadm versionkubeadm version: &version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.1", GitCommit:"4485c6f18cee9a5d3c3b4e523bd27972b1b53892", GitTreeState:"clean", BuildDate:"2019-07-18T09:15:32Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"}

4、查看升级计划，通过kubeadm可以查看当前集群的升级计划，会显示当前小版本最新的版本以及社区最新的版本

[root@node-1 ~]# 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: v1.14.1  #当前集群版本[upgrade/versions] kubeadm version: v1.15.1  #当前kubeadm版本[upgrade/versions] Latest stable version: v1.15.3 #社区最新版本[upgrade/versions] Latest version in the v1.14 series: v1.14.6 #1.14.x中最新的版本Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':COMPONENT   CURRENT       AVAILABLEKubelet     3 x v1.14.1   v1.14.6Upgrade to the latest version in the v1.14 series:COMPONENT            CURRENT   AVAILABLE #可升级的版本信息，当前可从1.14.1升级至1.14.6版本API Server           v1.14.1   v1.14.6Controller Manager   v1.14.1   v1.14.6Scheduler            v1.14.1   v1.14.6Kube Proxy           v1.14.1   v1.14.6CoreDNS              1.3.1     1.3.1Etcd                 3.3.10    3.3.10You can now apply the upgrade by executing the following command:    kubeadm upgrade apply v1.14.6 #升级至1.14.6执行的操作命令_____________________________________________________________________Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':COMPONENT   CURRENT       AVAILABLEKubelet     3 x v1.14.1   v1.15.3Upgrade to the latest stable version:COMPONENT            CURRENT   AVAILABLE #跨版本升级的版本，当前最新的版本是1.15.3API Server           v1.14.1   v1.15.3Controller Manager   v1.14.1   v1.15.3Scheduler            v1.14.1   v1.15.3Kube Proxy           v1.14.1   v1.15.3CoreDNS              1.3.1     1.3.1Etcd                 3.3.10    3.3.10You can now apply the upgrade by executing the following command:    kubeadm upgrade apply v1.15.3 #升级至社区最新的版本执行的操作Note: Before you can perform this upgrade, you have to update kubeadm to v1.15.3._____________________________________________________________________

5、当前镜像没有下载最新镜像，本文以升级1.1.5.1版本为例，升级其他版本相类似，需要确保当前集群已获取到相关镜像，升级过程中也会更新证书，可通过--certificate-renewal=false关闭证书升级，升级至1.15.1版本操作如下：

[root@node-1 ~]# kubeadm upgrade apply v1.15.1[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/version] You have chosen to change the cluster version to "v1.15.1"[upgrade/versions] Cluster version: v1.14.1[upgrade/versions] kubeadm version: v1.15.1[upgrade/confirm] Are you sure you want to proceed with the upgrade? [y/N]: y 版本升级信息，确认操作[upgrade/prepull] Will prepull images for components [kube-apiserver kube-controller-manager kube-scheduler etcd][upgrade/prepull] Prepulling image for component etcd.[upgrade/prepull] Prepulling image for component kube-apiserver.[upgrade/prepull] Prepulling image for component kube-controller-manager.[upgrade/prepull] Prepulling image for component kube-scheduler.[apiclient] Found 0 Pods for label selector k8s-app=upgrade-prepull-kube-controller-manager[apiclient] Found 0 Pods for label selector k8s-app=upgrade-prepull-kube-apiserver[apiclient] Found 0 Pods for label selector k8s-app=upgrade-prepull-etcd[apiclient] Found 0 Pods for label selector k8s-app=upgrade-prepull-kube-scheduler[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-kube-controller-manager[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-kube-scheduler[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-etcd[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-kube-apiserver[upgrade/prepull] Prepulled image for component kube-controller-manager.[upgrade/prepull] Prepulled image for component kube-scheduler.[upgrade/prepull] Prepulled image for component etcd.[upgrade/prepull] Prepulled image for component kube-apiserver. #拉取镜像的步骤[upgrade/prepull] Successfully prepulled the images for all the control plane components[upgrade/apply] Upgrading your Static Pod-hosted control plane to version "v1.15.1"...Static pod: kube-apiserver-node-1 hash: bdf7ffba48feb2fc4c7676e7525066fdStatic pod: kube-controller-manager-node-1 hash: ecf9c37413eace225bc60becabeddb3bStatic pod: kube-scheduler-node-1 hash: f44110a0ca540009109bfc32a7eb0baa[upgrade/etcd] Upgrading to TLS for etcd #开始更新静态pod，及master上的每个节点[upgrade/staticpods] Writing new Static Pod manifests to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests122291749"[upgrade/staticpods] Preparing for "kube-apiserver" upgrade[upgrade/staticpods] Renewing apiserver certificate[upgrade/staticpods] Renewing apiserver-kubelet-client certificate[upgrade/staticpods] Renewing front-proxy-client certificate[upgrade/staticpods] Renewing apiserver-etcd-client certificate #更新证书[upgrade/staticpods] Moved new manifest to "/etc/kubernetes/manifests/kube-apiserver.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests-2019-09-15-12-41-40/kube-apiserver.yaml"[upgrade/staticpods] Waiting for the kubelet to restart the component[upgrade/staticpods] This might take a minute or longer depending on the component/version gap (timeout 5m0s)Static pod: kube-apiserver-node-1 hash: bdf7ffba48feb2fc4c7676e7525066fdStatic pod: kube-apiserver-node-1 hash: bdf7ffba48feb2fc4c7676e7525066fdStatic pod: kube-apiserver-node-1 hash: bdf7ffba48feb2fc4c7676e7525066fdStatic pod: kube-apiserver-node-1 hash: 4cd1e2acc44e2d908fd2c7b307bfce59[apiclient] Found 1 Pods for label selector component=kube-apiserver[upgrade/staticpods] Component "kube-apiserver" upgraded successfully! #更新成功[upgrade/staticpods] Preparing for "kube-controller-manager" upgrade[upgrade/staticpods] Renewing controller-manager.conf certificate[upgrade/staticpods] Moved new manifest to "/etc/kubernetes/manifests/kube-controller-manager.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests-2019-09-15-12-41-40/kube-controller-manager.yaml"[upgrade/staticpods] Waiting for the kubelet to restart the component[upgrade/staticpods] This might take a minute or longer depending on the component/version gap (timeout 5m0s)Static pod: kube-controller-manager-node-1 hash: ecf9c37413eace225bc60becabeddb3bStatic pod: kube-controller-manager-node-1 hash: 17b23c8c6fcf9b9f8a3061b3a2fbf633[apiclient] Found 1 Pods for label selector component=kube-controller-manager[upgrade/staticpods] Component "kube-controller-manager" upgraded successfully!#更新成功[upgrade/staticpods] Preparing for "kube-scheduler" upgrade[upgrade/staticpods] Renewing scheduler.conf certificate[upgrade/staticpods] Moved new manifest to "/etc/kubernetes/manifests/kube-scheduler.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests-2019-09-15-12-41-40/kube-scheduler.yaml"[upgrade/staticpods] Waiting for the kubelet to restart the component[upgrade/staticpods] This might take a minute or longer depending on the component/version gap (timeout 5m0s)Static pod: kube-scheduler-node-1 hash: f44110a0ca540009109bfc32a7eb0baaStatic pod: kube-scheduler-node-1 hash: 18859150495c74ad1b9f283da804a3db[apiclient] Found 1 Pods for label selector component=kube-scheduler[upgrade/staticpods] Component "kube-scheduler" upgraded successfully! #更新成功[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace[kubelet] Creating a ConfigMap "kubelet-config-1.15" in namespace kube-system with the configuration for the kubelets in the cluster[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.15" ConfigMap in the kube-system namespace[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster[addons] Applied essential addon: CoreDNS[addons] Applied essential addon: kube-proxy[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.15.1". Enjoy! #更新成功提示[upgrade/kubelet] Now that your control plane is upgraded, please proceed with upgrading your kubelets if you haven't already done so.

6、上述可看到master升级成功的信息，升级指特定版本只需要在apply的后面指定具体的版本即可，升级完完master后可以升级各个组件的plugin，详情参考不同网络的升级步骤，如flannel，calico等，升级过程升级对应的DaemonSets即可。

7、升级kubelet版本并重启kubelet服务，至此，master节点版本升级完毕。

[root@node-1 ~]# yum install -y kubelet-1.15.1-0 kubectl-1.15.1-0 --disableexcludes=kubernetes[root@node-1 ~]# systemctl daemon-reload[root@node-1 ~]# systemctl restart kubelet

2.3 升级worker节点

1、升级kubeadm和kubelet软件包

[root@node-2 ~]# yum install -y kubelet-1.15.1-0  --disableexcludes=kubernetes[root@node-2 ~]# yum install -y kubeadm-1.15.1-0 --disableexcludes=kubernetes[root@node-2 ~]# yum install -y kubectl-1.15.1-0 --disableexcludes=kubernetes

2、设置节点进入维护模式并驱逐worker节点上的应用，会将出了DaemonSets之外的其他应用迁移到其他节点上

设置维护和驱逐：[root@node-1 ~]# kubectl drain node-2 --ignore-daemonsetsnode/node-2 cordonedWARNING: ignoring DaemonSet-managed Pods: kube-system/kube-flannel-ds-amd64-tm6wj, kube-system/kube-proxy-2wqhjevicting pod "coredns-5c98db65d4-86gg7"evicting pod "demo-7b86696648-djvgb"pod/demo-7b86696648-djvgb evictedpod/coredns-5c98db65d4-86gg7 evictednode/node-2 evicted查看node的情况，此时node-2多了SchedulingDisabled标识位，即新的node都不会调度到该节点上[root@node-1 ~]# kubectl get nodesNAME     STATUS                     ROLES    AGE   VERSIONnode-1   Ready                      master   26h   v1.15.1node-2   Ready,SchedulingDisabled      26h   v1.14.1node-3   Ready                         26h   v1.14.1查看node-2上的pods，pod都已经迁移到其他node节点上[root@node-1 ~]# kubectl get pods --all-namespaces -o wide NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE    IP               NODE     NOMINATED NODE   READINESS GATESdefault       demo-7b86696648-6f22r            1/1     Running   0          30s    10.244.2.5       node-3              default       demo-7b86696648-fjmxn            1/1     Running   0          116m   10.244.2.2       node-3              default       demo-7b86696648-nwwxf            1/1     Running   0          116m   10.244.2.3       node-3              kube-system   coredns-5c98db65d4-cqbbl         1/1     Running   0          30s    10.244.0.6       node-1              kube-system   coredns-5c98db65d4-g59qt         1/1     Running   2          28m    10.244.2.4       node-3              kube-system   etcd-node-1                      1/1     Running   0          13m    10.254.100.101   node-1              kube-system   kube-apiserver-node-1            1/1     Running   0          13m    10.254.100.101   node-1              kube-system   kube-controller-manager-node-1   1/1     Running   0          13m    10.254.100.101   node-1              kube-system   kube-flannel-ds-amd64-99tjl      1/1     Running   1          26h    10.254.100.101   node-1              kube-system   kube-flannel-ds-amd64-jp594      1/1     Running   0          26h    10.254.100.103   node-3              kube-system   kube-flannel-ds-amd64-tm6wj      1/1     Running   0          26h    10.254.100.102   node-2              kube-system   kube-proxy-2wqhj                 1/1     Running   0          28m    10.254.100.102   node-2              kube-system   kube-proxy-k7c4f                 1/1     Running   1          27m    10.254.100.101   node-1              kube-system   kube-proxy-zffgq                 1/1     Running   0          28m    10.254.100.103   node-3              kube-system   kube-scheduler-node-1            1/1     Running   0          13m    10.254.100.101   node-1              

3、升级worker节点

[root@node-2 ~]# kubeadm upgrade node [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[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.15" 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.

4、重启kubelet服务

[root@node-2 ~]# systemctl daemon-reload[root@node-2 ~]# systemctl restart kubelet

5、取消节点调度标志，确保worker节点可正常调度

[root@node-1 ~]# kubectl uncordon node-2node/node-2 uncordoned[root@node-1 ~]# kubectl get nodes NAME     STATUS   ROLES    AGE   VERSIONnode-1   Ready    master   27h   v1.15.1node-2   Ready       27h   v1.15.1 #已升级成功node-3   Ready       27h   v1.14.1

按照上述步骤升级node-3节点，如下是升级完成后所有节点版本状态：

[root@node-1 ~]# kubectl get nodesNAME     STATUS   ROLES    AGE   VERSIONnode-1   Ready    master   27h   v1.15.1node-2   Ready       27h   v1.15.1node-3   Ready       27h   v1.15.1

2.3 升级原理

1、kubeadm upgrade apply执行动作

• 检查集群是否具备更新条件，检查apiserver处于可用状态，所有node处于ready状态，确保cs组件正常
• 强制版本更新策略
• 检查更新所需镜像是否下载或者可拉取
• 更新所有控制节点组件，确保异常时能回滚到原有状态
• 更新kube-dns和kube-proxy的配置文件，确保所需的的RBAC授权配置正常
• 生成新的证书文件并备份证书（当证书超时超过180天）

2、kubeadm upgrade node执行动作

• 从kubeadm中获取ClusterConfiguration，即从集群中获取到更新集群的配置文件并应用
• 更新node节点上的kubelet配置信息和软件

3. 更新集群至最新版本

截止至2019.9.15，当前kubernetes社区最新版本是1.15.3，本文演示以在线的方式升级kubernetes集群至1.15.3版本，步骤和前文操作类似。

1、安装最新软件包，kubeadm，kubelet，kubectl,三个节点均需要安装

[root@node-1 ~]# yum install kubeadm kubectl kubelet 已加载插件：fastestmirror, langpacksLoading mirror speeds from cached hostfile正在解决依赖关系--> 正在检查事务---> 软件包 kubeadm.x86_64.0.1.15.1-0 将被 升级---> 软件包 kubeadm.x86_64.0.1.15.3-0 将被 更新---> 软件包 kubectl.x86_64.0.1.15.1-0 将被 升级---> 软件包 kubectl.x86_64.0.1.15.3-0 将被 更新---> 软件包 kubelet.x86_64.0.1.15.1-0 将被 升级---> 软件包 kubelet.x86_64.0.1.15.3-0 将被 更新--> 解决依赖关系完成依赖关系解决======================================================================================================================================================================== Package                                架构                                  版本                                      源                                         大小========================================================================================================================================================================正在更新: kubeadm                                x86_64                                1.15.3-0                                  kubernetes                                8.9 M kubectl                                x86_64                                1.15.3-0                                  kubernetes                                9.5 M kubelet                                x86_64                                1.15.3-0                                  kubernetes                                 22 M事务概要========================================================================================================================================================================升级  3 软件包

2、升级master节点

查看升级计划[root@node-1 ~]# 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: v1.15.1[upgrade/versions] kubeadm version: v1.15.3[upgrade/versions] Latest stable version: v1.15.3[upgrade/versions] Latest version in the v1.15 series: v1.15.3Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':COMPONENT   CURRENT       AVAILABLEKubelet     3 x v1.15.1   v1.15.3Upgrade to the latest version in the v1.15 series:COMPONENT            CURRENT   AVAILABLEAPI Server           v1.15.1   v1.15.3Controller Manager   v1.15.1   v1.15.3Scheduler            v1.15.1   v1.15.3Kube Proxy           v1.15.1   v1.15.3CoreDNS              1.3.1     1.3.1Etcd                 3.3.10    3.3.10You can now apply the upgrade by executing the following command:    kubeadm upgrade apply v1.15.3_____________________________________________________________________升级master节点[root@node-1 ~]# kubeadm upgrade apply v1.15.3

3、升级worker节点,以此升级node-2和node-3节点

设置五污点去驱逐[root@node-1 ~]# kubectl drain node-2 --ignore-daemonsets执行升级操作[root@node-2 ~]# kubeadm upgrade node [root@node-2 ~]# systemctl daemon-reload[root@node-2 ~]# systemctl restart kubelet取消调度标志位[root@node-1 ~]# kubectl uncordon node-2 node/node-2 uncordoned确认版本升级[root@node-1 ~]# kubectl get nodes NAME     STATUS   ROLES    AGE   VERSIONnode-1   Ready    master   27h   v1.15.3node-2   Ready       27h   v1.15.3node-3   Ready       27h   v1.15.1

4、所有节点升级后的状态

所有node状态[root@node-1 ~]# kubectl get nodes NAME     STATUS   ROLES    AGE   VERSIONnode-1   Ready    master   27h   v1.15.3node-2   Ready       27h   v1.15.3node-3   Ready       27h   v1.15.3查看组件状态[root@node-1 ~]# kubectl get componentstatuses NAME                 STATUS    MESSAGE             ERRORscheduler            Healthy   ok                  controller-manager   Healthy   ok                  etcd-0               Healthy   {"health":"true"}   查看应用状态[root@node-1 ~]# kubectl get deployments --all-namespaces NAMESPACE     NAME      READY   UP-TO-DATE   AVAILABLE   AGEdefault       demo      3/3     3            3           160mkube-system   coredns   2/2     2            2           27h查看DaemonSets状态[root@node-1 ~]# kubectl get daemonsets --all-namespaces NAMESPACE     NAME                    DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR                   AGEkube-system   kube-flannel-ds-amd64   3         3         3       3            3           beta.kubernetes.io/arch=amd64   27hkube-system   kube-proxy              3         3         3       3            3           beta.kubernetes.io/os=linux     27h

看完上述内容，你们对kubernetes的 升级更新有进一步的了解吗？如果还想学到更多技能或想了解更多相关内容，欢迎关注行业资讯频道，感谢各位的阅读。