kubectl describe pod
- Docker & Kubernetes course
- Intermediate
- Lesson 74/82
- 4 min
Learn to inspect Pod issues with describe.
kubectl describe pod
If a pod never starts there are no logs either; the answer is in the Events section of the describe output. Common causes:
Events:
Warning Failed kubelet Failed to pull image "api:1.1": not found
Warning BackOff kubelet Back-off pulling image "api:1.1" # ImagePullBackOff
Warning FailedScheduling default-scheduler 0/3 nodes are available: 3 Insufficient memory.
Warning FailedMount kubelet configmap "api-ayar" not found
Warning Unhealthy kubelet Readiness probe failed: HTTP probe failed with statuscode: 503Filtering events
Events are kept for about an hour. To see only warnings or a specific object, they are filtered:
kubectl get events --field-selector type=Warning
kubectl get events --field-selector involvedObject.name=api-xyz
kubectl describe pod api-xyz | sed -n '/Events/,$p'
kubectl get pod api-xyz -o jsonpath='{.status.containerStatuses[0].state}'Practice Find the cause from the events
Write three commands: show the api-xyz pod in detail; list only the events of type Warning; list only the events of the api-xyz object with involvedObject.name.
Starter code
# buraya yazSample solution
kubectl describe pod api-xyz
kubectl get events --field-selector type=Warning
kubectl get events --field-selector involvedObject.name=api-xyzExpected output
Name: api-xyz Status: Pending Events: Warning Failed kubelet Failed to pull image "api:1.1": not found LAST SEEN TYPE REASON OBJECT MESSAGE 2m Warning Failed pod/api-xyz Failed to pull image "api:1.1": not found
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What are the most common causes of ImagePullBackOff?
- Insufficient memory
- An application bug
- A wrong port
- A wrong image name/tag or missing imagePullSecrets for a private registry Correct answer
Explanation: The "not found" vs "unauthorized" distinction in the event shows the cause.
2 Show only the warning events.
Question
kubectl get events --field-selector type=____
Answer
kubectl get events --field-selector type=WarningExplanation: Event types are Normal and Warning.
3 Match the events.
| Term | Meaning |
|---|---|
Failed to pull image |
Image couldn't be pulled |
Insufficient memory |
No room on the nodes |
configmap not found |
Missing config |
Readiness probe failed |
Not ready |