How to Upgrade a Worker Node with Kubeadm
After upgrading the control plane using kubeadm, you need to update the kubelet configuration on the node. Which command should you run on the node?
⚠ Common exam trap
Test-takers frequently confuse `kubeadm upgrade apply` (for the first control-plane node) with `kubeadm upgrade node` (for worker nodes), or they invent a non-existent `kubectl upgrade node` command because they expect kubectl to manage node upgrades.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
kubeadm upgrade node
`kubeadm upgrade node` is the command used on worker nodes (or secondary control-plane nodes) after the primary control plane has been upgraded. It upgrades the kubelet configuration and other node-specific components to match the new cluster version, ensuring the node can rejoin the upgraded cluster.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
kubeadm upgrade apply
Why it's wrong here
This command is executed on the very first control plane node to initiate the cluster-wide upgrade process, download the new control plane images, and update the local manifests. It is not the command used on subsequent control plane nodes or worker nodes after the initial control plane upgrade has already been completed.
- ✗
kubectl upgrade node
Why it's wrong here
The kubectl command-line tool is designed for interacting with the Kubernetes API server to manage resources and does not feature an upgrade subcommand. Node and cluster upgrades are administrative tasks managed directly on the host operating system using the kubeadm utility.
- ✓
kubeadm upgrade node
Why this is correct
Once the primary control plane node is upgraded, you must run this command on all other control plane nodes and worker nodes to upgrade their local configurations. This command fetches the cluster configuration from the API server and updates the local kubelet configuration files and certificates accordingly.
- ✗
kubeadm upgrade plan
Why it's wrong here
This command is a dry-run utility used prior to starting an upgrade to check which Kubernetes versions are available and verify that the cluster is in a healthy state for the transition. It merely outputs a detailed upgrade plan and does not apply any actual configuration changes to the node or control plane.
Go deeper
Related to this question
About these practice questions
One of 726 original CKA practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on CKA
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. You need to upgrade a Kubernetes cluster from v1.28 to v1.29 using kubeadm. After upgrading the control plane, what should you do on each worker node?
medium- A.kubeadm upgrade node config --kubelet-version v1.29.0
- B.kubectl delete node <node>; kubeadm upgrade node
- ✓ C.kubectl drain <node>; kubeadm upgrade node; kubectl uncordon <node>
- D.kubeadm upgrade node; kubectl uncordon <node>
Why C: The standard kubeadm upgrade workflow for worker nodes requires first draining the node to safely evict all pods, then running 'kubeadm upgrade node' to upgrade the kubelet and kube-proxy configuration, and finally uncordoning the node to make it schedulable again. This sequence ensures minimal disruption to workloads and follows the official Kubernetes upgrade documentation.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CKA practice question is part of Courseiva's free CNCF certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CKA exam.