Master 100 Essential kubectl Commands for Rapid Kubernetes Troubleshooting

Introduction

This article provides a comprehensive list of 100 commonly used kubectl commands for diagnosing Kubernetes clusters, helping you troubleshoot issues efficiently.

Cluster Information

kubectl version

– Show Kubernetes version. kubectl cluster-info – Display cluster information. kubectl get nodes – List all nodes. kubectl describe node <node-name> – Show details of a specific node. kubectl get namespaces – List all namespaces. kubectl get pods --all-namespaces – List all pods across namespaces.

Pod Diagnosis

kubectl get pods -n <namespace>

– List pods in a namespace. kubectl describe pod <pod-name> -n <namespace> – Show pod details. kubectl logs <pod-name> -n <namespace> – View pod logs. kubectl logs -f <pod-name> -n <namespace> – Follow pod logs.

kubectl exec -it <pod-name> -n <namespace> -- <command>

– Execute a command inside a pod.

Pod Health Checks

kubectl get pods <pod-name> -n <namespace> -o jsonpath='{.status.conditions[?(@.type=="Ready")].status}'

– Check pod readiness.

kubectl get events -n <namespace> --field-selector involvedObject.name=<pod-name>

– View pod events.

Service Diagnosis

kubectl get svc -n <namespace>

– List services.

kubectl describe svc <service-name> -n <namespace>

– Show service details.

Deployment Diagnosis

kubectl get deployments -n <namespace>

– List deployments.

kubectl describe deployment <deployment-name> -n <namespace>

– Show deployment details.

kubectl rollout status deployment/<deployment-name> -n <namespace>

– Check rollout status.

kubectl rollout history deployment/<deployment-name> -n <namespace>

– View rollout history.

StatefulSet Diagnosis

kubectl get statefulsets -n <namespace>

– List StatefulSets.

kubectl describe statefulset <statefulset-name> -n <namespace>

– Show details.

ConfigMap and Secret Diagnosis

kubectl get configmaps -n <namespace>

– List ConfigMaps.

kubectl describe configmap <configmap-name> -n <namespace>

– Show ConfigMap details. kubectl get secrets -n <namespace> – List Secrets.

kubectl describe secret <secret-name> -n <namespace>

– Show Secret details.

Namespace Diagnosis

kubectl describe namespace <namespace-name>

– Show namespace details.

Resource Usage

kubectl top pod <pod-name> -n <namespace>

– Check pod CPU/memory. kubectl top nodes – Check node resource usage.

Network Diagnosis

kubectl get pods -n <namespace> -o custom-columns=POD:metadata.name,IP:status.podIP --no-headers

– Show pod IPs. kubectl get networkpolicies -n <namespace> – List network policies.

kubectl describe networkpolicy <network-policy-name> -n <namespace>

– Show policy details.

Persistent Volume (PV) and Persistent Volume Claim (PVC) Diagnosis

kubectl get pv

– List PVs. kubectl describe pv <pv-name> – Show PV details. kubectl get pvc -n <namespace> – List PVCs. kubectl describe pvc <pvc-name> -n <namespace> – Show PVC details.

Node Diagnosis

kubectl get pods --field-selector spec.nodeName=<node-name> -n <namespace>

– List pods on a node.

Resource Quotas and Limits

kubectl get resourcequotas -n <namespace>

– List resource quotas.

kubectl describe resourcequota <resource-quota-name> -n <namespace>

– Show quota details.

Custom Resource Definition (CRD) Diagnosis

kubectl get <custom-resource-name> -n <namespace>

– List custom resources.

kubectl describe <custom-resource-name> <custom-resource-instance-name> -n <namespace>

– Show details.

Scaling and Autoscaling

kubectl scale deployment <deployment-name> --replicas=<replica-count> -n <namespace>

– Scale a deployment.

kubectl autoscale deployment <deployment-name> --min=<min-pods> --max=<max-pods> --cpu-percent=<cpu-percent> -n <namespace>

– Set autoscaling. kubectl get hpa -n <namespace> – Check Horizontal Pod Autoscaler status.

Job and CronJob Diagnosis

kubectl get jobs -n <namespace>

– List jobs. kubectl describe job <job-name> -n <namespace> – Show job details. kubectl get cronjobs -n <namespace> – List CronJobs.

kubectl describe cronjob <cronjob-name> -n <namespace>

– Show CronJob details.

Capacity Diagnosis

kubectl get pv --sort-by=.spec.capacity.storage

– List PVs sorted by capacity.

kubectl get pv <pv-name> -o=jsonpath='{.spec.persistentVolumeReclaimPolicy}'

– Show PV reclaim policy. kubectl get storageclasses – List storage classes.

Ingress and Service Mesh Diagnosis

kubectl get ingress -n <namespace>

– List Ingresses.

kubectl describe ingress <ingress-name> -n <namespace>

– Show Ingress details. kubectl get virtualservices -n <namespace> – List Istio VirtualServices.

kubectl describe virtualservice <virtualservice-name> -n <namespace>

– Show VirtualService details.

Pod Network Troubleshooting

kubectl run -it --rm --restart=Never --image=busybox net-debug-pod -- /bin/sh

– Launch a debugging pod.

kubectl exec -it <pod-name> -n <namespace> -- curl <endpoint-url>

– Test connectivity.

kubectl exec -it <source-pod-name> -n <namespace> -- traceroute <destination-pod-ip>

– Trace network path.

kubectl exec -it <pod-name> -n <namespace> -- nslookup <domain-name>

– Check DNS resolution.

Configuration and Resource Validation

kubectl apply --dry-run=client -f <yaml-file>

– Validate YAML without applying.

kubectl auth can-i list pods --as=system:serviceaccount:<namespace>:<serviceaccount-name>

– Verify pod security context.

RBAC and Security

kubectl get roles,rolebindings -n <namespace>

– List roles and bindings. kubectl describe role <role-name> -n <namespace> – Show role details.

Service Account Diagnosis

kubectl get serviceaccounts -n <namespace>

– List service accounts.

kubectl describe serviceaccount <serviceaccount-name> -n <namespace>

– Show account details.

Node Drain and Uncordon

kubectl drain <node-name> --ignore-daemonsets

– Drain a node for maintenance. kubectl uncordon <node-name> – Uncordon a node.

Resource Cleanup

kubectl delete pod <pod-name> -n <namespace> --grace-period=0 --force

– Force delete a pod (use with caution).

Pod Affinity and Anti‑Affinity

kubectl get pod <pod-name> -n <namespace> -o=jsonpath='{.spec.affinity}'

– Show pod affinity rules.

kubectl get pod <pod-name> -n <namespace> -o=jsonpath='{.spec.affinity.podAntiAffinity}'

– Show anti‑affinity rules.

Pod Security Policy (PSP)

kubectl get psp

– List all PSPs.

Events

kubectl get events --sort-by=.metadata.creationTimestamp

– List recent cluster events. kubectl get events -n <namespace> – Filter events by namespace.

Node Conditions (Kubernetes 1.17+)

kubectl get nodes -o custom-columns=NODE:.metadata.name,READY:.status.conditions[?(@.type=="Ready")].status -l 'node-role.kubernetes.io/worker='

– Custom node readiness output.

Audit Logs

Retrieve audit logs if enabled to understand cluster activity.

Node OS Details

kubectl get node <node-name> -o jsonpath='{.status.nodeInfo.osImage}'

– Get node operating system image.

Replace placeholders such as <namespace>, <pod-name>, <service-name>, <deployment-name>, etc., with actual values from your cluster.