kubeadm方式升级k8s集群

最新推荐文章于 2025-04-26 01:02:15 发布

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最新推荐文章于 2025-04-26 01:02:15 发布

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文章标签： kubernetes 容器云原生 kubeadm k8s

本文链接：https://blog.youkuaiyun.com/liuguizhong/article/details/147034601

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一、注意事项

升级前最好备份所有组件及数据，例如etcd

不要跨两个大版本进行升级，可能会存在版本bug，如：

1.19.4-->1.20.4 可以

1.19.4-->1.21.4 不可以

跨多个版本的可以逐个版本进行升级。

二、查看当前版本

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-master1 ~]<span style="color:#787878"># kubectl get nodes</span>
NAME          STATUS   ROLES                  AGE   VERSION
k8s-master1   Ready    control-plane,master   41d   v1.20.4
k8s-node1     Ready    jenkins,node           41d   v1.20.4
k8s-node2     Ready    gitlab,node            38d   v1.20.4</code></span></span></span></span>

目前我的版本是v1.20.4，官网最新版本已经到1.25.0。升级到最新版本需要逐步升级：v1.20.4-->v1.21.4-->v1.22.4-->v1.23.4-->v1.24.4-->v1.25.0，共升级5次。

三、确定当前版本

先配置阿里云yum源，每台节点都需要配置

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-master1 yum.repos.d]<span style="color:#787878"># pwd</span>
/etc/yum.repos.d
[root@k8s-master1 yum.repos.d]<span style="color:#787878"># cat kubernetes.repo</span>
[kubernetes]
<span style="color:#919e6b">name</span><span style="color:#919e6b">=</span>Kubernetes
<span style="color:#919e6b">baseurl</span><span style="color:#919e6b">=</span>https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
<span style="color:#919e6b">enabled</span><span style="color:#919e6b">=</span><span style="color:#cf694a">1</span>
<span style="color:#919e6b">gpgcheck</span><span style="color:#919e6b">=</span><span style="color:#cf694a">0</span>
<span style="color:#919e6b">repo_gpgcheck</span><span style="color:#919e6b">=</span><span style="color:#cf694a">0</span>
<span style="color:#919e6b">gpgkey</span><span style="color:#919e6b">=</span>https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg</code></span></span></span></span>

配置后更新yum源，执行命令：

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash"><span style="color:#787878">#yum clean all</span>
<span style="color:#787878">#yum makecache</span></code></span></span></span></span>

查询版本，会列出目前所有的正式版本，我们现在从1.20.4升级到1.21版本，所以需要找到v.1.21.4版本号

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-master1 yum.repos.d]<span style="color:#787878"># yum list --showduplicates kubeadm --disableexcludes=kubernetes</span></code></span></span></span></span>

四、开始升级---升级 master 节点

4.1 在 master 节点上执行如下命令，升级 kubeadm，对应的版本必须一致v1.24.4

如果是高可用集群，找其中一台master执行以下命令

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-master1 ~]<span style="color:#787878"># yum install -y kubeadm-1.21.4-0 --disableexcludes=kubernetes</span>

Upgrade  <span style="color:#cf694a">1</span> Package

Total download size: <span style="color:#cf694a">9.1</span> M
Downloading packages:
Delta RPMs disabled because /usr/bin/applydeltarpm not installed.
61c56c520cec529ff02ca33f37f190d23253acff6e84bd695cc045cdd4f52b2e-kubeadm-1.21.4-0.x86_64.rpm                                                 <span style="color:#919e6b">|</span> <span style="color:#cf694a">9.1</span> MB  00:01:24
Running transaction check
Running transaction <span style="color:#f9ee9a">test</span>
Transaction <span style="color:#f9ee9a">test</span> succeeded
Running transaction
  Updating   <span style="color:#f9ee9a">:</span> kubeadm-1.21.4-0.x86_64                                                                                                                          <span style="color:#cf694a">1</span>/2
  Cleanup    <span style="color:#f9ee9a">:</span> kubeadm-1.20.4-0.x86_64                                                                                                                          <span style="color:#cf694a">2</span>/2
  Verifying  <span style="color:#f9ee9a">:</span> kubeadm-1.21.4-0.x86_64                                                                                                                          <span style="color:#cf694a">1</span>/2
  Verifying  <span style="color:#f9ee9a">:</span> kubeadm-1.20.4-0.x86_64                                                                                                                          <span style="color:#cf694a">2</span>/2

Updated:
  kubeadm.x86_64 <span style="color:#cf694a">0</span>:1.21.4-0

Complete<span style="color:#919e6b">!</span></code></span></span></span></span>

4.2、在同一台master上继续继续以下命令，kubeadm更新计划

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-master1 ~]<span style="color:#787878"># kubeadm upgrade plan</span></code></span></span></span></span>

kubeadm更新计划会打印出目前能支持到的版本，显示我最高可以升级到v1.21.14，由于前面kubeadmin更新的是v1.21.4版本，后续也必须保持统一版本，如果这里apply了1.21.14会报错

在打印信息中可以看到，升级集群每个组件对应的当前版本和升级后的版本。而且升级的组件只包括kube-apiserver，kube-controller-manager，kube-scheduler，kube-proxy，CoreDNS，etcd。

不包括kubectl,kubelet,docker和网络组件flannel等

4.3 根据上面输出提示，执行如下命令以升级：

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-master1 ~]<span style="color:#787878"># kubeadm upgrade apply v1.21.4</span>
....
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs <span style="color:#f9ee9a">in</span> order <span style="color:#f9ee9a">for</span> 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 <span style="color:#f9ee9a">for</span> all node client certificates <span style="color:#f9ee9a">in</span> the cluster
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

[upgrade/successful] SUCCESS<span style="color:#919e6b">!</span> Your cluster was upgraded to <span style="color:#919e6b">"v1.21.4"</span><span style="color:#f9ee9a">.</span> Enjoy<span style="color:#919e6b">!</span>

[upgrade/kubelet] Now that your control plane is upgraded, please proceed with upgrading your kubelets <span style="color:#f9ee9a">if</span> you haven't already <span style="color:#f9ee9a">done</span> so.
<span style="color:#787878">#升级成功</span></code></span></span></span></span>

如果是高可用还需要在其他 master 节点上执行命令:

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">kubeadm upgrade node</code></span></span></span></span>

在所有的 master 节点上执行如下命令升级 kubelet 和 kubectl

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-master1 ~]<span style="color:#787878"># yum install -y kubelet-1.21.4-0 kubectl-1.21.4-0 --disableexcludes=kubernetes</span></code></span></span></span></span>

执行如下命令，以重启 kubelet

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-master1 ~]<span style="color:#787878"># systemctl daemon-reload && systemctl restart kubelet</span></code></span></span></span></span>

五、升级 node 节点

5.1 在所有的 node 节点上执行如下命令，升级 kubeadm

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-node2 ~]<span style="color:#787878"># yum install -y kubeadm-1.21.4-0 --disableexcludes=kubernetes</span></code></span></span></span></span>

5.2 升级 kubelet 的配置，在所有node节点上执行

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-node2 ~]<span style="color:#787878"># kubeadm upgrade node</span>
[upgrade] Reading configuration from the cluster...
[upgrade] FYI: You can look at this config file with <span style="color:#919e6b">'kubectl -n kube-system get cm kubeadm-config -o yaml'</span>
[preflight] Running pre-flight checks
[preflight] Skipping prepull. Not a control plane node.
[upgrade] Skipping phase. Not a control plane node.
[kubelet-start] Writing kubelet configuration to file <span style="color:#919e6b">"/var/lib/kubelet/config.yaml"</span>
[upgrade] The configuration <span style="color:#f9ee9a">for</span> this node was successfully updated<span style="color:#919e6b">!</span>
[upgrade] Now you should go ahead and upgrade the kubelet package using your package manager.</code></span></span></span></span>

5.3 升级 kubelet 和 kubectl

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-node2 ~]<span style="color:#787878"># yum install -y kubelet-1.21.4-0 kubectl-1.21.4-0 --disableexcludes=kubernetes</span></code></span></span></span></span>

执行如下命令，以重启 kubelet

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-node2 ~]<span style="color:#787878"># systemctl daemon-reload && systemctl restart kubelet</span></code></span></span></span></span>

六、检查集群的状态

版本已经从v1.20.4升级到v1.21.4

<span style="color:#424242"><span style="background-color:#ffffff"><span style="background-color:#212121"><span style="color:#ffffff"><code class="language-bash">[root@k8s-master1 ~]<span style="color:#787878"># kubectl get nodes</span>
NAME          STATUS   ROLES                  AGE   VERSION
k8s-master1   Ready    control-plane,master   41d   v1.21.4
k8s-node1     Ready    jenkins,node           41d   v1.21.4
k8s-node2     Ready    gitlab,node            38d   v1.21.4</code></span></span></span></span>