CKAD Application Design and Build Practice Question
You need to debug a running pod that does not have a shell installed. Which kubectl command allows you to start an ephemeral container with a shell?
⚠ Common exam trap
Test-takers frequently confuse `kubectl exec` (which requires a shell in the existing container) with `kubectl debug` (which adds a new container with a shell), or mistakenly think `kubectl run` or `kubectl create pod` can attach to an existing pod's context.
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
✓
kubectl debug <pod> --image=busybox --stdin --tty
`kubectl debug` is specifically designed to add an ephemeral container to a running pod for troubleshooting purposes, even when the original container lacks a shell. The `--image=busybox` flag provides a lightweight image with common debugging tools, and `--stdin --tty` allocates an interactive terminal, allowing you to run commands like `/bin/sh` inside the ephemeral container without modifying the original pod's containers.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
kubectl create pod debug --image=busybox --attach
Why it's wrong here
This creates a new pod, not an ephemeral container in the existing pod.
- ✗
kubectl exec -it <pod> -- /bin/sh
Why it's wrong here
kubectl exec requires the container to have a shell. If the container does not have a shell, this will fail.
- ✓
kubectl debug <pod> --image=busybox --stdin --tty
Why this is correct
kubectl debug adds an ephemeral container to the pod with the specified image and attaches to it.
- ✗
kubectl run debug --image=busybox --attach
Why it's wrong here
This creates a new pod, not an ephemeral container in the existing pod.
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