Kubernetes CKA sample exam question 68 with answer

Question
Your coworker said node cluster3-worker2 is running an older Kubernetes version and is not even part of the cluster.
Update Kubernetes on that node to the exact version that's running on cluster3-master1.
Then add this node to the cluster. Use kubeadm for this.

Answer
Get cluster information:

kubectl get nodes

can be observed that there are 2 nodes; cluster3-master1 and cluster3-worker1, both running on version v1.24.1.
SSh to master:

ssh cluster3-master1

and check kubeadmin and kubelet version:

kubeadm version
kubelet --version

the both version reported is v1.24.1.
SSH to problematic node:

ssh cluster3-worker2

and check the same:

kubeadm version
kubelet --version

kubeadm reports version v1.24.1 and this is fine and kubelet reports version v1.23.1 - it should be upgraded.
Do an package info update:

apt update

and check version v1.24.1 for kubelet:

apt-cache madison kubelet | grep 1.24.1

Install this version:

apt-mark unhold kubelet
apt install -y kubelet=1.24.1-00
apt-mark hold kubelet

Restart kubelet:

systemctl daemon-reload
systemctl restart kubelet

On master node we need to print a join command for this node:

kubeadm token create --print-join-command

Copy the output and paste it on node cluster3-worker2.
Wait some time and check if node joined the cluster:

kubectl get nodes

The node cluster3-worker2 should be Ready after some time