k8s v1.14.1都已经发布了，为了学习搭建的k8s集群(v1.13.3)需要升级到最新版。虽然有官方升级文档，但是自己原来是手动搭建的是基于CoreOS的k8s集群[搭建访问见以前的文章]，虽然步骤大概相同，但是个别细节不太一样。
备份
cp -r /opt/bin /opt/bin_v1.13.3
准备新版命令行文件
下面的命令在国内不能访问，请使用梯子
RELEASE=v1.14.1
mkdir -p /opt/bin_v1.14.1
cd /opt/bin_v1.14.1
curl -L --remote-name-all https://storage.googleapis.com/kubernetes-release/release/${RELEASE}/bin/linux/amd64/{kubeadm,kubelet,kubectl}
chmod +x {kubeadm,kubelet,kubectl}
可以通过查看版本判断下载是否正确
/opt/bin_v1.14.1/kubeadm version
/opt/bin_v1.14.1/kubectl version
/opt/bin_v1.14.1/kubelet --version
升级master节点
更新kubeadm
cp /opt/bin_v1.14.1/kubeadm /opt/bin/
kubeadm version
升级前的check
sudo kubeadm upgrade plan
输出类似:
因为本人操作的时候没有保存，所以下面的信息可能和真实的不太一样，真实的会因为网络问题，报一些warn，但是实际没有什么问题
[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
Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':
COMPONENT CURRENT AVAILABLE
Kubelet 2 x v1.13.3 v1.14.0
Upgrade to the latest version in the v1.13 series:
COMPONENT CURRENT AVAILABLE
API Server v1.13.3 v1.14.0
Controller Manager v1.13.3 v1.14.0
Scheduler v1.13.3 v1.14.0
Kube Proxy v1.13.3 v1.14.0
CoreDNS 1.2.6 1.3.1
Etcd 3.2.24 3.3.10
You can now apply the upgrade by executing the following command:
kubeadm upgrade apply v1.14.0
_____________________________________________________________________
开始升级
sudo kubeadm upgrade apply v1.14.x
更新kubectl
cp /opt/bin_v1.14.1/kubectl /opt/bin/
更新kubelet
sudo systemctl stop kubelet
cp /opt/bin_v1.14.1/kubelet /opt/bin/
sudo systemctl start kubelet
升级worker节点
为了保证在升级时k8s集群上已经在跑的服务依然正常提供服务，最好是一次升级一个worker节点。这点在官方文档做了说明，但是我的k8s集群上暂时没有跑什么服务，所以这块还没有验证，准备在下次升级的到更新的版本是做一个验证。
更新kubeadm
cp /opt/bin_v1.14.1/kubeadm /opt/bin/
kubeadm version
下掉某个worker节点
kubectl drain $NODE --ignore-daemonsets
$NODE是节点名称，和kubectl get nodes中NAME对应
升级配置
sudo kubeadm upgrade node config --kubelet-version v1.14.1
更新kubectl
cp /opt/bin_v1.14.1/kubectl /opt/bin/
更新kubelet
sudo systemctl stop kubelet
cp /opt/bin_v1.14.1/kubelet /opt/bin/
sudo systemctl start kubelet
查看升级是否成功
kubectl get nodes
如果VERSION已经变为1.14.1，说明升级成功
某个worker节点上线
kubectl uncordon $NODE
$NODE是节点名称，和kubectl get nodes中NAME对应
按照以上步骤，将所有的worker节点都升级完成即可。
最终验证
kubectl get nodes
我的集群的输出变为了
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 82d v1.14.1
k8s-node-1 Ready <none> 82d v1.14.1
k8s-node-2 Ready <none> 82d v1.14.1
k8s-node-3 Ready <none> 82d v1.14.1
DONE!