This CKS practice question tests your understanding of cluster setup and hardening. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which admission plugin should be enabled on the kube-apiserver to restrict kubelet permissions and prevent nodes from modifying their own Node objects?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
NodeRestriction
The NodeRestriction admission plugin limits the kubelet's permissions to only modify labels, annotations, and status on its own Node object, preventing a compromised or misconfigured node from altering other Node objects or escalating privileges. This is a critical hardening measure for cluster setup, as it enforces the principle of least privilege on kubelet API access.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
ServiceAccount
Why it's wrong here
The ServiceAccount admission plugin manages service account automount, not kubelet permissions.
✗
AlwaysPullImages
Why it's wrong here
This plugin ensures images are always pulled, but does not restrict kubelet.
✓
NodeRestriction
Why this is correct
The NodeRestriction admission plugin limits the kubelet to only modify its own Node object and pods bound to it.
Related concept
Read the scenario before looking for a memorised answer.
✗
PodSecurityPolicy
Why it's wrong here
PodSecurityPolicy is deprecated and does not restrict kubelet node modifications.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse admission plugins that restrict pod behavior (like PodSecurityPolicy or AlwaysPullImages) with those that restrict node/kubelet behavior, leading them to pick a security-focused but irrelevant option for this specific kubelet permission control question.
Detailed technical explanation
How to think about this question
The NodeRestriction plugin works by intercepting requests from kubelets (identified via their x509 client certificate CN, typically system:node:<nodeName>) and ensuring they can only write to the Node object matching their node name, and only to specific subresources like /status and /proxy. Under the hood, it leverages the SubjectAccessReview API and the node authorizer, which together enforce that a kubelet cannot create or delete Node objects, nor modify any Node object other than its own, even if the RBAC rules are misconfigured. In a real-world scenario, if a node is compromised and the kubelet credentials are stolen, NodeRestriction prevents the attacker from tampering with other nodes' labels or taints, which could otherwise disrupt scheduling or cluster operations.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A junior network technician can log in to a core router but cannot reach the enable prompt or configuration mode. The AAA server is authenticating the login — but the authorisation policy only grants privilege level 1, not 15. Authentication (who you are) is working; authorisation (what you can do) is not.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CKS question in full detail.
Cluster Setup and Hardening — This question tests Cluster Setup and Hardening — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: NodeRestriction — The NodeRestriction admission plugin limits the kubelet's permissions to only modify labels, annotations, and status on its own Node object, preventing a compromised or misconfigured node from altering other Node objects or escalating privileges. This is a critical hardening measure for cluster setup, as it enforces the principle of least privilege on kubelet API access.
What should I do if I get this CKS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This CKS 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 CKS exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.