KCNA Kubernetes Fundamentals Practice Question
An administrator notices that a pod in a Deployment is stuck in CrashLoopBackOff. The pod logs show 'Error: failed to start container: exec: "app": executable file not found in $PATH'. What is the most likely cause?
⚠ Common exam trap
CNCF often tests the distinction between image pull errors (ImagePullBackOff) and container execution errors (CrashLoopBackOff), so candidates may confuse missing credentials with a missing executable in the image.
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
✓
The container image does not contain the binary specified in the pod's command field
The error 'exec: "app": executable file not found in $PATH' indicates that the container image does not contain the binary or script specified in the pod's command field (e.g., `command: ["app"]`). This typically happens when the image is built without the expected executable, the command path is incorrect, or the image tag points to a different version. The container fails to start because the runtime cannot locate the entrypoint.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The image registry credentials are missing
Why it's wrong here
Missing credentials would cause ImagePullBackOff, not CrashLoopBackOff with this error.
- ✗
The liveness probe is misconfigured and killing the container
Why it's wrong here
A failing probe would show probe failures in events, not an exec error.
- ✗
The container is running as a non-root user without proper permissions
Why it's wrong here
Permission issues would show 'permission denied', not 'executable file not found'.
- ✓
The container image does not contain the binary specified in the pod's command field
Why this is correct
The exec error shows the binary is missing, likely due to a typo or wrong image.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This KCNA 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 KCNA exam.