[Master node] upgrade control-plan v1.16.12 > v1.17.17 (CentOS)

ref. https://v1-17.docs.kubernetes.io/docs/tasks/administer-cluster/kubeadm/kubeadm-upgrade/

1.Add Kubernetes Repository

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF

2.Find the latest stable 1.17 version:

yum list --showduplicates kubeadm --disableexcludes=kubernetes
# find the latest 1.17 version in the list
# it should look like 1.17.x-0, where x is the latest patch

3.Upgrade the first control plane node

# replace x in 1.17.x-0 with the latest patch version
yum install -y kubeadm-1.17.17-0 --disableexcludes=kubernetes

4.Verify that the download works and has the expected version

$kubeadm version
 kubeadm version: &version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.17", GitCommit:"f3abc15296f3a3f54e4ee42e830c61047b13895f", GitTreeState:"clean", BuildDate:"2021-01-13T13:18:52Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}

5.On the control plane node, run:

kubeadm upgrade plan

6.Review kubeadm plan

Upgrade to the latest version in the v1.16 series:
COMPONENT            CURRENT   AVAILABLE
API Server           v1.16.0   v1.17.0
Controller Manager   v1.16.0   v1.17.0
Scheduler            v1.16.0   v1.17.0
Kube Proxy           v1.16.0   v1.17.0
CoreDNS              1.6.2     1.6.5
Etcd                 3.3.15    3.4.3-0
You can now apply the upgrade by executing the following command:
    kubeadm upgrade apply v1.17.17

7.Choose a version to upgrade to, and run the appropriate command. For example:

sudo kubeadm upgrade apply v1.17.17

8.Drain the control plane node

kubectl drain <cp-node-name> --ignore-daemonsets

9.Upgrade kubelet and kubectl

# replace x in 1.17.x-0 with the latest patch version
yum install -y kubelet-1.17.17-0 kubectl-1.17.17-0 --disableexcludes=kubernetes

10.Restart the kubelet

sudo systemctl restart kubelet

11.Verify kubelet/kubectl version

$kubelet --version
 Kubernetes v1.17.17
$kubectl version
Client Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.17", GitCommit:"f3abc15296f3a3f54e4ee42e830c61047b13895f", GitTreeState:"clean", BuildDate:"2021-01-13T13:21:12Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.17", GitCommit:"f3abc15296f3a3f54e4ee42e830c61047b13895f", GitTreeState:"clean", BuildDate:"2021-01-13T13:13:00Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}

12.Uncordon the control plane node

# replace <cp-node-name> with the name of your control plane node
kubectl uncordon <cp-node-name>

13.Verify the status of the cluster

After the kubelet is upgraded on all nodes verify that all nodes are available again by running the following command from anywhere kubectl can access the cluster:

kubectl get nodes
kubectl  get pod -n kube-system

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