Kubernetes Commands for Daily Troubleshooting

Kubernetes, the powerful container orchestration platform, is the backbone of modern cloud-native applications. However, its complexity can be overwhelming when troubleshooting issues. Whether you're dealing with pod failures, network issues, or scaling challenges, knowing the right commands is crucial to keep your cluster running smoothly.

This article highlights 30 essential Kubernetes troubleshooting commands every DevOps engineer and administrator should master to streamline daily operations.

1. Cluster Information and Health Checks

Start by ensuring the health and status of your Kubernetes cluster.

Get cluster information
```
 kubectl cluster-info
```
Displays essential details about your cluster, including the API server and endpoints.
Check cluster nodes
```
 kubectl get nodes
```
Lists all nodes in the cluster and their statuses.
Detailed node status
```
 kubectl describe node <node-name>
```
Provides detailed information about a specific node, including resource allocation and issues.
Check cluster events
```
 kubectl get events --sort-by='.metadata.creationTimestamp'
```
View the latest cluster-wide events for identifying potential problems.

2. Pod Management and Debugging

List all pods
```
 kubectl get pods -A
```
Displays pods across all namespaces to identify issues at a glance.
Detailed pod information
```
 kubectl describe pod <pod-name>
```
Offers a detailed breakdown of a pod’s configuration and current state.
View pod logs
```
 kubectl logs <pod-name>
```
Access logs to debug application-level issues.
Stream pod logs
```
 kubectl logs -f <pod-name>
```
Continuously stream logs for real-time monitoring.
Execute commands in a pod
```
 kubectl exec -it <pod-name> -- /bin/bash
```
Access the shell of a running container for troubleshooting.
Check pod resource usage

kubectl top pod <pod-name>

Displays CPU and memory usage for a pod.

3. Network and Connectivity

Inspect services

kubectl get svc

Lists all services to ensure proper exposure and routing of applications.

Debug service issues

kubectl describe svc <service-name>

Provides details about a specific service, including associated endpoints.

Test DNS resolution

kubectl exec -it <pod-name> -- nslookup <service-name>

Check if DNS resolution is working within the cluster.

Inspect network policies

kubectl get networkpolicy

Ensures proper access control between pods and services.

Trace service endpoints

kubectl get endpoints <service-name>

Validates the service is mapping to the correct pods.

4. Deployment and Replica Management

List deployments

kubectl get deployments

Ensures deployments are running as expected.

Inspect deployment status

kubectl describe deployment <deployment-name>

Provides details about replica counts and issues during updates.

Scale a deployment

kubectl scale deployment <deployment-name> --replicas=<number>

Adjust the number of replicas to handle workload demands.

Rollback a deployment

kubectl rollout undo deployment <deployment-name>

Reverts to the previous stable deployment state.

Check rollout status

kubectl rollout status deployment <deployment-name>

Ensures the deployment update is proceeding as expected.

5. Persistent Volumes and Storage

List persistent volumes

kubectl get pv

View the status of persistent volumes in the cluster.

Inspect persistent volume claims

kubectl get pvc

Verifies if pods are correctly bound to storage.

Describe a persistent volume

kubectl describe pv <pv-name>

Provides details about storage capacity and access modes.

6. Resource Monitoring and Usage

Check resource usage by node

kubectl top node

Displays CPU and memory usage across all nodes.

Check pod resource limits

kubectl describe pod <pod-name> | grep -i "limits"

Validates resource limits defined for pods.

Monitor resource quotas

kubectl get resourcequotas

Ensures namespaces are within resource allocation limits.

7. Configuration and Secrets

List config maps

kubectl get configmaps

Lists all ConfigMaps in the current namespace.

Inspect secrets

kubectl get secrets

Ensures secure information is properly configured and accessible.

8. Miscellaneous Utilities

Dry-run a deployment

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

Tests changes without applying them to the cluster.

Delete a problematic resource

kubectl delete pod <pod-name>

Removes malfunctioning pods to free up resources.

Conclusion

Troubleshooting Kubernetes effectively involves understanding its architecture and mastering key commands. The 30 commands we've discussed cover many scenarios, helping you diagnose and fix issues efficiently.

As you get more comfortable with these commands, you'll notice a significant improvement in managing complex Kubernetes environments. Keep this list handy, practice often, and enhance your DevOps workflow!

What are your favorite Kubernetes troubleshooting commands? Share them in the comments! 🚀

💻Mastering Kubernetes Troubleshooting: 30 Essential Commands for Day-to-Day Operations 🚀