Metrics, logs, traces and dashboards that answer real questions.
3 items at beginner level · all topics
A container is in CrashLoopBackOff and kubectl logs returns nothing useful because the container has just restarted. Which command shows the output from the failed run?
kubectl logs --previous returns the logs of the previous instantiation of the container, which is where the reason for the crash actually is.
You are asked to find out what happened in a namespace over the last few minutes. Which command gives the most useful ordered picture, and what limitation should you expect?
kubectl get events --sort-by=.lastTimestamp gives a namespace timeline. Events are namespaced and short-lived, retained for one hour by default, so older history is simply gone.
kubectl top nodes fails with an error saying the metrics API is not available, though every node is Ready and workloads are healthy. What does that indicate?
kubectl top reads the Metrics API, which is served by metrics-server rather than by the API server itself. Without it installed there is nothing to answer, and resource usage has to come from elsewhere.