- A
runAsUser: 1000
Why wrong: This is only a key-value pair; it must be nested under securityContext.
- B
securityContext: runAsUser: 1000
This sets the container's user ID to 1000, ensuring it does not run as root.
- C
securityContext: { runAsNonRoot: true }
Why wrong: This only prevents running as root but does not set a specific user ID.
- D
user: 1000
Why wrong: 'user' is not a valid field in the Kubernetes security context.
Question 517 of 997
Pod Security Context — runAsUser for Non-Root
This CKS practice question tests your understanding of supply chain security. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
An administrator wants to ensure that all containers in a deployment run as a non-root user. Which YAML snippet correctly sets the security context to run as user ID 1000?
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
✓
securityContext: runAsUser: 1000
Option B is correct because it correctly sets the security context at the pod or container level with the `runAsUser` field, which instructs the container runtime (e.g., containerd) to set the user ID to 1000 for the container's main process. This ensures the container does not run as root (UID 0), aligning with the principle of least privilege.
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.
- ✗
runAsUser: 1000
Why it's wrong here
This is only a key-value pair; it must be nested under securityContext.
- ✓
securityContext: runAsUser: 1000
Why this is correct
This sets the container's user ID to 1000, ensuring it does not run as root.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
securityContext: { runAsNonRoot: true }
Why it's wrong here
This only prevents running as root but does not set a specific user ID.
- ✗
user: 1000
Why it's wrong here
'user' is not a valid field in the Kubernetes security context.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The CNCF CKS exam often tests the distinction between `runAsUser` (which sets a specific UID) and `runAsNonRoot` (which only prevents root but does not enforce a particular UID), causing candidates to pick option C when the question explicitly asks for user ID 1000.
Detailed technical explanation
How to think about this question
Under the hood, when `runAsUser` is set, the kubelet passes the user ID to the container runtime (e.g., containerd or CRI-O), which uses Linux kernel capabilities like `setuid` to drop privileges before executing the container's entrypoint. A real-world scenario is running a web server container that should not have root access to the host filesystem; setting `runAsUser: 1000` ensures that even if the container is compromised, the attacker gains only the permissions of UID 1000, not root.
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.
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
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Certified Kubernetes Security Specialist CKS study guide
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CKS practice test guide
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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: securityContext: runAsUser: 1000 — Option B is correct because it correctly sets the security context at the pod or container level with the `runAsUser` field, which instructs the container runtime (e.g., containerd) to set the user ID to 1000 for the container's main process. This ensures the container does not run as root (UID 0), aligning with the principle of least privilege.
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.
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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 →
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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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