Copy file from pod

Download a file from a running container

kubectl cp mynamespace/mypod:/var/log/app.log ./app.log
tool
k8s-debug27 commands
tags
k8s-debugkubectl

More k8s-debug commands

  • Top pods by restart count
    kubectl get po -A --sort-by='.status.containerStatuses[0].restartCount' | tail -20

    Rank pods cluster-wide by restart count to spot crash loops fast

  • Detect OOMKilled containers
    kubectl get po -A -o jsonpath='{range .items[*]}{.metadata.namespace}{" "}{.metadata.name}{" "}{.status.containerStatuses[*].lastState.terminated.reason}{"\n"}{end}' | grep OOMKilled

    List pods whose last container exit was OOMKilled across all namespaces

  • Pending pods scheduling reason
    kubectl get po -A --field-selector=status.phase=Pending -o name | xargs -I{} kubectl describe {} -n <ns> | grep -A3 FailedScheduling

    Extract FailedScheduling reasons for every Pending pod (taints, resources, affinity)

  • Node NotReady triage
    kubectl describe node <node> | grep -A12 Conditions; ssh <node> 'journalctl -u kubelet -n 100 --no-pager'

    Read node Conditions then tail kubelet journal to find why node is NotReady

  • ImagePullBackOff root cause
    kubectl get events -n <ns> --field-selector reason=Failed -o wide | grep -i 'pull\|manifest\|unauthorized'

    Surface registry pull failures: bad tag, missing imagePullSecret, or rate limit

all 27 k8s-debug commands