k8s集群升级

前言:
  生产环境的k8s为了追求稳定,不能直接安装最新版本,随着新版本功能的稳定,很多新功能是老版本不具备的,这时进行一次稳妥的升级便是一个不错的选择。

以升级k8s集群v1.13.3到v1.14.0为例

升级次序:先升级master,后升级node
升级之前的准备:确保已经备份了etcd数据库与master节点的状态

升级master

安装kubernetes的yum源

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
 
name=Kubernetes repo
 
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
 
gpgcheck=0
 
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
 
enabled=1

EOF

yum makecache
yum list --showduplicates kubeadm --disableexcludes=kubernetes
# find the latest 1.14 version in the list
# it should look like 1.14.x-0, where x is the latest patch

安装完yum源后,可以用这个命令来查看相关的安装包:

yum list kubeadm --showduplicates -y | sort -r
或者yum list --showduplicates kubeadm --disableexcludes=kubernetes

安装v1.14.0的kubeadm与kubelet安装包

yum install -y kubeadm-1.14.0-0 kubelet-1.14.0-0 kubectl-1.14.0-0 

验证下载的包是否为期望的版本

sudo kubeadm version

期望输出
kubeadm version: &version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.0", GitCommit:"641856db18352033a0d96dbc99153fa3b27298e5", GitTreeState:"clean", BuildDate:"2019-03-25T15:51:21Z", GoVersion:"go1.12.1", Compiler:"gc", Platform:"linux/amd64"}

验证集群是否可升级

sudo kubeadm upgrade plan

期望输出
[preflight] Running pre-flight checks.
[upgrade] Making sure the cluster is healthy:
[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'
[upgrade] Fetching available versions to upgrade to
[upgrade/versions] Cluster version: v1.13.3
[upgrade/versions] kubeadm version: v1.14.0

Awesome, you're up-to-date! Enjoy!

执行升级

sudo kubeadm upgrade apply v1.14.0
交互界面输入y,确认升级
期望输出
[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.14.0". Enjoy!

升级kubectl

yum install -y  kubectl-1.14.0-0

重启kubelet

sudo systemctl daemon-reload && sudo systemctl restart kubelet

查看升级结果

NAME        STATUS   ROLES    AGE   VERSION
k8s-agent   Ready    <none>   66m   v1.13.3
k8s-cp      Ready    master   69m   v1.14.0

升级node

安装kubernetes的yum源

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
 
name=Kubernetes repo
 
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
 
gpgcheck=0
 
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
 
enabled=1

EOF

yum makecache

安装v1.14.0的kubeadm与kubelet安装包

yum install -y kubeadm-1.14.0-0 kubelet-1.14.0-0

修改kubelet配置

sudo kubeadm upgrade node config --kubelet-version v1.14.0

升级kubectl

yum install -y  kubectl-1.14.0-0 

重启kubelet

sudo systemctl daemon-reload && sudo systemctl restart kubelet

查看升级结果

NAME        STATUS   ROLES    AGE   VERSION
k8s-agent   Ready    <none>   70m   v1.14.0
k8s-cp      Ready    master   73m   v1.14.0

参考
补充第一点:如果k8s使用的是动态调度,那么在升级node节点之前,应该将其标记为不可用,从集群中剔出:
通过将节点标记为不可调度并删除工作负载,为维护节点做好准备。运行:

kubectl drain $NODE --ignore-daemonsets

你应该看到类似这样的输出:

node/ip-172-31-85-18 cordoned
WARNING: ignoring DaemonSet-managed Pods: kube-system/kube-proxy-dj7d7, kube-system/weave-net-z65qx

node/ip-172-31-85-18 drained

补充第二点:本博客最多可升级至1.15版本,1.15-->1.16版本需要加参数如下

kubeadm upgrade apply v1.16.10 --ignore-preflight-errors=CoreDNSUnsupportedPlugins

补充第三点:离线更新时,不但要下载kubeadm,kubectl,kubelet的安装包,还要在线环境下升级成功所下载的docker镜像,并将其离线上传,才能离线升级成功

在离线安装kubeadm,kubectl,kubelet时,可以用yumdownloader下载,yum install *来安装

安装完离线包之后,可以使用这个来命令查看 kubeadm init 时所需要的组件镜像列表:

 kubeadm config images list
posted @ 2020-06-17 14:33  小雨淅淅o0  阅读(1249)  评论(0编辑  收藏  举报