Kubernetes Cluster Health Check

16 items · Devops · Hard difficulty · 1 hour

Quick, actionable Kubernetes cluster health checks for DevOps teams.

• Check control plane component health

  Verify kube-apiserver, controller-manager, scheduler are running and responsive.

• Verify etcd cluster health and backups

  Run etcdctl/cluster-health and confirm a recent successful backup exists.

• Confirm all nodes are Ready and clear pressures

  Run kubectl get nodes and inspect diskPressure/memoryPressure/NetworkUnavailable.

• Inspect pods for CrashLoopBackOff and OOMKilled

  List failing pods across namespaces and prioritize repeating failures.

• Describe affected pods and recent events

  Use kubectl describe pod to see events and termination reasons.

• Collect container logs from failing pods

  Fetch current and previous logs (kubectl logs --previous) for crash context.

• Audit resource requests and limits for workloads

  Identify missing or unrealistic requests/limits that cause scheduling or OOMs.

• List pods missing CPU/memory requests or limits

  Query deployments/statefulsets and flag pods without requests/limits.

• Check PersistentVolume and PVC capacity and I/O errors

  Inspect PVC usage and storage class events for provisioning or I/O failures.

• Scan certificate expiry for cluster and TLS certs

  Find certificates near expiry for kube-apiserver, kubelet, and ingress endpoints.

• Check kube-apiserver and kubelet certificate expiry

  Use kubeadm or openssl to inspect API server and node cert dates.

• Ensure metrics-server and cluster metrics are available

  Confirm kubectl top nodes/pods works and metrics-server pods are Ready.

• Test HPA scaling behavior

  Generate load and verify HPA scales pods as expected and stabilizes.

• Run image vulnerability scanning for container images

  Scan images with Trivy/Clair and prioritize fixing high CVEs in production images.

• Review RBAC bindings for over-permissive roles

  List ClusterRoleBindings and tighten any broad or unused privileges.

• Validate DNS resolution and service endpoints

  Test CoreDNS pods, resolve service names, and curl critical service endpoints.

Printed from TickYouOff — the interactive version tracks your progress and can be shared with others.