准备

1、首先升级master节点的基础组件kubeadm、kubelet、kubectl
apt-get update && apt-get upgrade  kubeadm 

更新到1.13.0后，在master执行,执行一次

kubeadm upgrade plan

[upgrade/versions] Latest version in the v1.12 series: v1.13.0

External components that should be upgraded manually before you upgrade the control plane with 'kubeadm upgrade apply':
COMPONENT   CURRENT   AVAILABLE
Etcd        3.2.22    3.2.24

Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':
COMPONENT   CURRENT       AVAILABLE
Kubelet     1 x v1.12.0   v1.13.0
            2 x v1.13.0   v1.13.0

Upgrade to the latest version in the v1.12 series:

COMPONENT            CURRENT   AVAILABLE
API Server           v1.12.0   v1.13.0
Controller Manager   v1.12.0   v1.13.0
Scheduler            v1.12.0   v1.13.0
Kube Proxy           v1.12.0   v1.13.0
CoreDNS              1.2.2     1.2.6

You can now apply the upgrade by executing the following command:

  kubeadm upgrade apply v1.13.0
需要先升级etcd服务，我们的版本是3.2.22，需要升级到3.2.24

2、备份etcd数据(以防万一)
 etcdctl snapshot save backup.db

 查看备份的状态
 etcdctl --write-out=table snapshot status backup.db

3、下载新的etcd，这里我们部署1.13.0的kubernetes需要的是3.2.24
[](https://github.com/etcd-io/etcd/releases/download/v3.2.24/etcd-v3.2.24-linux-amd64.tar.gz)

  wget https://github.com/etcd-io/etcd/releases/download/v3.2.24/etcd-v3.2.24-linux-amd64.tar.gz

由于之前部署的是三节点的etcd集群，所以可以做到无缝升级，一个节点一个节点进行升级，每个节点恢复正常后在升级下一个节点；
1）停掉当前节点
 systemctl stop etcd

2）将下载好的文件解压，然后替换之前的etcd和etcdctl，替换完成后启动etcd

 systemctl start etcd

3）每个节点替换完成后检查服务状态

 etcdctl endpoint health

Upgrade master and node packages

kubectl drain node_name --ignore-daemonsets

master节点需要加上--ignore-daemonsets，node节点不用

更新
apt-get update
apt-get upgrade -y  kubeadm

更新过程中要保证服务不中断，轮询替换更新

Upgrade kubelet on each node

1)On each node except the master node, upgrade the kubelet config:

kubeadm upgrade node config --kubelet-version \$(kubelet --version | cut -d ' ' -f 2)

2)Restart the kubelet process:

systemctl restart kubelet

3)Verify that the new version of the kubelet is running on the node:

systemctl status kubelet

4)Bring the node back online by marking it schedulable:

kubectl uncordon \$NODE

5)verify that all nodes are available again by running the following command from anywhere kubectl can access the cluster:

kubectl get nodes

The STATUS column should show Ready for all your nodes, and the version number should be updated.

Rolling update

如果升级失败了，一般会自动回滚到之前的版本，如果出现异常没有回退到之前的版本，可以再次执行kubeadm upgrade
kubeadm upgrade apply v1.12.0 --force

参考：https://kubernetes.io/docs/tasks/administer-cluster/kubeadm/kubeadm-upgrade-1-13/

原文地址：https://www.cnblogs.com/cuishuai/p/10078300.html