- A
Increase the memory limit of the API server
Why wrong: Memory limit of API server does not affect the webhook communication.
- B
Change the webhook from 'MutatingAdmissionWebhook' to 'ValidatingAdmissionWebhook'
Why wrong: ImagePolicyWebhook is a separate admission controller; changing webhook type does not address connectivity.
- C
Set failurePolicy to Ignore in the webhook configuration
When the webhook cannot be reached, the API server rejects the request. Setting failurePolicy: Ignore allows pods to be admitted even if the webhook is unavailable, but this is a temporary fix. The root cause might be network connectivity to the webhook service.
- D
Grant the webhook service account cluster-admin role
Why wrong: RBAC permissions for the webhook are not the issue; the webhook receives requests from the API server.
Troubleshooting ImagePolicyWebhook: When to Set failurePolicy to Ignore
This CKS practice question tests your understanding of supply chain security. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.
You are configuring ImagePolicyWebhook admission controller to reject images not signed by a trusted authority. After deploying the webhook, you notice that pods are being rejected even for images that are properly signed. Which configuration change is MOST likely to fix this?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"most likely"Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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
Set failurePolicy to Ignore in the webhook configuration
The ImagePolicyWebhook admission controller uses a webhook to validate images. When the webhook is unreachable or returns an error, the default behavior is to reject the request. Setting `failurePolicy` to `Ignore` allows the API server to admit the pod when the webhook fails, which is necessary if the webhook is temporarily unavailable or misconfigured but images are properly signed.
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.
- ✗
Increase the memory limit of the API server
Why it's wrong here
Memory limit of API server does not affect the webhook communication.
- ✗
Change the webhook from 'MutatingAdmissionWebhook' to 'ValidatingAdmissionWebhook'
Why it's wrong here
ImagePolicyWebhook is a separate admission controller; changing webhook type does not address connectivity.
- ✓
Set failurePolicy to Ignore in the webhook configuration
Why this is correct
When the webhook cannot be reached, the API server rejects the request. Setting failurePolicy: Ignore allows pods to be admitted even if the webhook is unavailable, but this is a temporary fix. The root cause might be network connectivity to the webhook service.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Grant the webhook service account cluster-admin role
Why it's wrong here
RBAC permissions for the webhook are not the issue; the webhook receives requests from the API server.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The CKS exam often tests the distinction between `failurePolicy: Fail` (default) and `failurePolicy: Ignore`, tricking candidates into thinking the issue is with webhook type or permissions rather than the failure handling behavior.
Detailed technical explanation
How to think about this question
The `failurePolicy` field in a ValidatingWebhookConfiguration (or MutatingWebhookConfiguration) controls how the API server behaves when the webhook is unreachable or returns an error. The default value is `Fail`, which causes the API server to reject the request. Setting it to `Ignore` allows the request to proceed, which is useful for non-critical webhooks or during transient failures. This is defined in the Kubernetes admission webhook API (v1) and is critical for high-availability scenarios where webhook downtime should not block pod creation.
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 practitioner preparing for the CKS exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Supply Chain Security — study guide chapter
Learn the concepts, then practise the questions
- →
Supply Chain Security practice questions
Targeted practice on this topic area only
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All CKS questions
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- →
Certified Kubernetes Security Specialist CKS study guide
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CKS practice test guide
How to use practice tests most effectively before exam day
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FAQ
Questions learners often ask
What does this CKS question test?
Supply Chain Security — This question tests Supply Chain Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Set failurePolicy to Ignore in the webhook configuration — The ImagePolicyWebhook admission controller uses a webhook to validate images. When the webhook is unreachable or returns an error, the default behavior is to reject the request. Setting `failurePolicy` to `Ignore` allows the API server to admit the pod when the webhook fails, which is necessary if the webhook is temporarily unavailable or misconfigured but images are properly signed.
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.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
Same concept, more angles
1 more ways this is tested on CKS
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. A cluster has the ImagePolicyWebhook admission controller enabled. A pod creation is denied with the message 'image policy check failed'. The webhook server returns an error. Which of the following could be a valid reason?
hard- ✓ A.The image is not signed by a trusted authority
- B.The container runtime is out of date
- C.The image tag does not exist in the registry
- D.The pod specification has a hostNetwork: true
Why A: The ImagePolicyWebhook admission controller intercepts pod creation requests and queries an external webhook server to determine whether the image should be allowed. If the webhook returns an error (e.g., HTTP 5xx or a denial response), the admission controller fails the request with 'image policy check failed'. A common reason for the webhook to deny the request is that the image is not signed by a trusted authority, as the webhook may be configured to enforce image signature verification (e.g., using Notary or Sigstore).
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Last reviewed: Jul 4, 2026
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.
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