# 100 Kubernetes Diagnostics Commands with Kubectl


### **Here is a list of 100** `kubectl` **commands that can be useful for diagnosing issues in a Kubernetes cluster.**

**Cluster Information:**

**1.** Show the Kubernetes version**:** `kubectl version`

2\. Display cluster information: `kubectl cluster-info`

**3.** List all nodes in the cluster: `kubectl get nodes`

**4.** Describe a specific node: `kubectl describe node <node-name>`

**5.** List all namespaces**:** `kubectl get namespaces`

**6.** List all pods in all namespaces: `kubectl get pods --all-namespaces`

**Pod Diagnostics:**

**1.** List pods in a specific namespace**:** `kubectl get pods -n <namespace>`

**2.** Describe a pod: `kubectl describe pod <pod-name> -n <namespace>`

**3.** View pod logs**:** `kubectl logs <pod-name> -n <namespace>`

**4.** Tail pod logs: `kubectl logs -f <pod-name> -n <namespace>`

**5.** Execute a command in a pod: `kubectl exec -it <pod-name> -n <namespace> -- <command>`

**Pod Health Checks:**

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

**2.** Check pod events**:** `kubectl get events -n <namespace> --field-selector` [`involvedObject.name`](http://involvedObject.name)`=<pod-name>`

**Service Diagnostics:**

**1.** List all services in a namespace: `kubectl get svc -n <namespace>`

**2.** Describe a service**:** `kubectl describe svc <service-name> -n <namespace>`

**Deployment Diagnostics:**

**1.** List all deployments in a namespace**:** `kubectl get deployments -n <namespace>`

**2.** Describe a deployment: `kubectl describe deployment <deployment-name> -n <namespace>`

**3.** View rollout status: `kubectl rollout status deployment/<deployment-name> -n <namespace>`

**4.** View rollout history: `kubectl rollout history deployment/<deployment-name> -n <namespace>`

**StatefulSet Diagnostics:**

**1.** List all StatefulSets in a namespace: `kubectl get statefulsets -n <namespace>`

**2.** Describe a StatefulSet**:** `kubectl describe statefulset <statefulset-name> -n <namespace>`

**ConfigMap and Secret Diagnostics:**

**1.** List ConfigMaps in a namespace**:** `kubectl get configmaps -n <namespace>`

**2.** Describe a ConfigMap**:** `kubectl describe configmap <configmap-name> -n <namespace>`

**3.** List Secrets in a namespace: `kubectl get secrets -n <namespace>`

**4.** Describe a Secret: `kubectl describe secret <secret-name> -n <namespace>`

**Namespace Diagnostics:**

**1.** Describe a namespace: `kubectl describe namespace <namespace-name>`

**Resource Usage:**

**1.** Check resource usage for a pod: `kubectl top pod <pod-name> -n <namespace>`

**2.** Check resource usage for nodes**:** `kubectl top nodes`

**Networking Diagnostics:**

1\. Show the IP addresses of pods in a namespace: `kubectl get pods -n <namespace -o custom-columns=POD:`[`metadata.name`](http://metadata.name)`,IP:status.podIP --no-headers`

**2.** List all network policies in a namespace: `kubectl get networkpolicies -n <namespace>`

**3.** Describe a network policy: `kubectl describe networkpolicy <network-policy-name> -n <namespace>`

**Persistent Volume (PV) and Persistent Volume Claim (PVC) Diagnostics:**

1\. List PVs: `kubectl get pv`

**2.** Describe a PV**:** `kubectl describe pv <pv-name>`

**3.** List PVCs in a namespace: `kubectl get pvc -n <namespace>`

**4.** Describe a PVC**:** `kubectl describe pvc <pvc-name> -n <namespace>`

**Node Diagnostics:**

`1.` Get the list of pods running on a specific node: `kubectl get pods --field-selector spec.nodeName=<node-name> -n <namespace>`

**Resource Quotas and Limits:**

**1.** List resource quotas in a namespace: `kubectl get resourcequotas -n <namespace>`

**2.** Describe a resource quota: `kubectl describe resourcequota <resource-quota-name> -n <namespace>`

**Custom Resource Definitions (CRD) Diagnostics:**

**1.** List custom resources in a namespace: `kubectl get <custom-resource-name> -n <namespace>`

**2.** Describe a custom resource**:** `kubectl describe <custom-resource-name> <custom-resource-instance-name> -n <namespace>`

Remember to replace `<namespace>`, `<pod-name>`, `<service-name>`, `<deployment-name>`, `<statefulset-name>`, `<configmap-name>`, `<secret-name>`, `<namespace-name>`, `<pv-name>`, `<pvc-name>`, `<node-name>`, `<network-policy-name>`, `<resource-quota-name>`, `<custom-resource-name>`, and `<custom-resource-instance-name>` with your specific values when using these commands. These commands should help you diagnose various aspects of your Kubernetes cluster and applications running within it.

**Resource Scaling and Autoscaling:**

**1.** Scale a deployment: `kubectl scale deployment <deployment-name> --replicas=<replica-count> -n <namespace>`

**2.** Set autoscaling for a deployment**:** `kubectl autoscale deployment <deployment-name> --min=<min-pods> --max=<max-pods> --cpu-percent=<cpu-percent> -n <namespace>`

**3.** Check horizontal pod autoscaler status**:** `kubectl get hpa -n <namespace>`

**Job and CronJob Diagnostics:**

**1.** List all jobs in a namespace**:** `kubectl get jobs -n <namespace>`

**2.** Describe a job**:** `kubectl describe job <job-name> -n <namespace>`

**3.** List all cron jobs in a namespace: `kubectl get cronjobs -n <namespace>`

**4.** Describe a cron job**:** `kubectl describe cronjob <cronjob-name> -n <namespace>`

**Volume Diagnostics:**

**1.** List persistent volumes (PVs) sorted by capacity**:** `kubectl get pv --sort-by=.`[`spec.capacity.storage`](http://spec.capacity.storage)

2\. Check PV reclaim policy: `kubectl get pv <pv-name> -o=jsonpath='{.spec.persistentVolumeReclaimPolicy}'`

**3.** List all storage classes**:** `kubectl get storageclasses`

**Ingress and Service Mesh Diagnostics:**

**1.** List all ingresses in a namespace: `kubectl get ingress -n <namespace>`

**2.** Describe an ingress**:** `kubectl describe ingress <ingress-name> -n <namespace>`

3\. List all VirtualServices (Istio) in a namespace: `kubectl get virtualservices -n <namespace>`

**4.** Describe a VirtualService (Istio**):** `kubectl describe virtualservice <virtualservice-name> -n <namespace>`

**Pod Network Troubleshooting:**

**1.** Run a network diagnostic pod (e.g., busybox) for debugging: `kubectl run -it --rm --restart=Never --image=busybox net-debug-pod -- /bin/sh`

**2.** Test connectivity from a pod to a specific endpoint**:** `kubectl exec -it <pod-name> -n <namespace> -- curl <endpoint-url>`

**3.** Trace network path from one pod to another: `kubectl exec -it <source-pod-name> -n <namespace> -- traceroute <destination-pod-ip>`

**4.** Check DNS resolution from a pod: `kubectl exec -it <pod-name> -n <namespace> -- nslookup <domain-name>`

**Config and Resource Validation:**

**1.** Validate a Kubernetes YAML file without applying it: `kubectl apply --dry-run=client -f <yaml-file>`

`2.` Validate a pod’s security context and capabilities: `kubectl auth can-i list pods --as=system:serviceaccount:<namespace>:<serviceaccount-name>`

**RBAC and Security:**

**1.** List roles and role bindings in a namespace: `kubectl get roles,rolebindings -n <namespace>`

**2.** Describe a role or role binding: `kubectl describe role <role-name> -n <namespace>`

**Service Account Diagnostics:**

**1.** List service accounts in a namespace: `kubectl get serviceaccounts -n <namespace>`

**2.** Describe a service account: `kubectl describe serviceaccount <serviceaccount-name> -n <namespace>`

**Node Drain and Uncordon:**

**1.** Drain a node for maintenance**:** `kubectl drain <node-name> --ignore-daemonsets`

**2.** Uncordon a previously drained node: `kubectl uncordon <node-name>`

**Resource Cleanup:**

**1.** Delete a pod forcefully (not recommended): `kubectl delete pod <pod-name> -n <namespace> --grace-period=0 --force`

**Pod Affinity and Anti-Affinity:**

**1.** List pod affinity rules for a pod: `kubectl get pod <pod-name> -n <namespace> -o=jsonpath='{.spec.affinity}'`

`2.` List pod anti-affinity rules for a pod: `kubectl get pod <pod-name> -n <namespace> -o=jsonpath='{.spec.affinity.podAntiAffinity}'`

**Pod Security Policies (PSP):**

**1.** List all pod security policies (if enabled): `kubectl get psp`

**Kubernetes Events:**

**1.** View recent cluster events: `kubectl get events --sort-by=.metadata.creationTimestamp`

**2.** Filter events by a specific namespace: `kubectl get events -n <namespace>`

**Node Troubleshooting:**

**1.** Check node conditions**:** `kubectl describe node <node-name> | grep Conditions -A5`

**2.** List node capacity and allocatable resources: `kubectl describe node <node-name> | grep -E "Capacity|Allocatable"`

**Ephemeral Containers (Kubernetes 1.18+):**

**1.** Run an ephemeral debugging container: `kubectl debug -it <pod-name> -n <namespace> --image=<debug-image> -- /bin/sh`

**Resource Metrics (Metrics Server required):**

`1.` Get CPU and Memory usage for pods: `kubectl top pod -n <namespace>`

**Kubelet Diagnostics:**

**1.** View kubelet logs on a node: `kubectl logs -n kube-system kubelet-<node-name>`

**Advanced Debugging with Telepresence:**

**1.** Debug a pod with Telepresence: `telepresence --namespace <namespace> --swap-deployment <pod-name>`

**Kubeconfig and Contexts:**

**1.** List available contexts: `kubectl config get-contexts`

**2.** Switch to a different context: `kubectl config use-context <context-name>`

**Pod Security Standards (PodSecurity admission controller):**

**1.** List PodSecurityPolicy (PSP) violations: `kubectl get psp -A | grep -vE 'NAME|REVIEWED'`

**Pod Disruption Budget (PDB) Diagnostics:**

**1.** List all PDBs in a namespace: `kubectl get pdb -n <namespace>`

**2.** Describe a PDB: `kubectl describe pdb <pdb-name> -n <namespace>`

**Resource Lock Diagnostics (if using resource locks):**

**1.** List resource locks in a namespace**:** `kubectl get resourcelocks -n <namespace>`

**Service Endpoints and DNS:**

**1.** List service endpoints for a service**:** `kubectl get endpoints <service-name> -n <namespace>`

**2.** Check DNS configuration in a pod: `kubectl exec -it <pod-name> -n <namespace> -- cat /etc/resolv.conf`

**Custom Metrics (Prometheus, Grafana):**

1\. Query Prometheus metrics: Use `kubectl port-forward` to access Prometheus and Grafana services to query custom metrics.

**Pod Priority and Preemption:**

**1.** List priority classes: `kubectl get priorityclasses`

**Pod Overhead (Kubernetes 1.18+):**

**1.** List overhead in a pod: `kubectl get pod <pod-name> -n <namespace> -o=jsonpath='{.spec.overhead}'`

**Volume Snapshot Diagnostics (if using volume snapshots):**

**1.** List volume snapshots**:** `kubectl get volumesnapshot -n <namespace>`

**2.** Describe a volume snapshot: `kubectl describe volumesnapshot <snapshot-name> -n <namespace>`

**Resource Deserialization Diagnostics:**

**1.** Deserialize and print a Kubernetes resource**:** `kubectl get <resource-type> <resource-name> -n <namespace> -o=json`

**Node Taints:**

**1.** List node taints: `kubectl describe node <node-name> | grep Taints`

**Mutating and Validating Webhook Configurations:**

**1.** List mutating webhook configurations**:** `kubectl get mutatingwebhookconfigurations`

**2.** List validating webhook configurations: `kubectl get validatingwebhookconfigurations`

**Pod Network Policies:**

`1.` List pod network policies in a namespace: `kubectl get networkpolicies -n <namespace>`

**Node Conditions (Kubernetes 1.17+):**

List node conditions: kubectl get nodes -o custom-columns=NODE:.[metadata.name](http://metadata.name),READY:.status.conditions\[?(@.type==”Ready”)\].status -l ‘[node-role.kubernetes.io/worker=’**Audit**](http://node-role.kubernetes.io/worker=’Audit) **Logs:**

1\. Retrieve audit logs (if enabled): Check your Kubernetes audit log configuration for the location of audit logs.

**Node Operating System Details:**

1\. Get the node’s OS information: `kubectl get node <node-name> -o jsonpath='{.status.nodeInfo.osImage}'`

**List All Running Pods in All Namespaces (Short Command):**

1\. List all running pods in all namespaces in a short format: `kubectl get pods --all-namespaces`

These commands should cover a wide range of diagnostics scenarios in Kubernetes. Make sure to replace placeholders like `<namespace>`, `<pod-name>`, `<deployment-name>`, etc., with actual values specific to your cluster and use case.