Recommended steps to resolve Kubernetes issue

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Use Case

• Recommended steps to resolve Kubernetes issue

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USE CASE

Recommended steps to resolve Kubernetes issues

Resolving issues in Kubernetes can be systematic and efficient if you follow a structured approach. Otherwise, Kubernetes is vast and involves many applications, services, databases and many more. So, once you stuck in any issue, it is very hard to get out of it. In this post, I am trying to recommend step-by-step process to debug and resolve Kubernetes issues.

In my previous post, I had highlighted, comprehensive list of errors with the aligned ecosystem of K8s. So, you can go through those errors as well.

Step-by-step process to debug and resolve issues

1. Identify and Understand the Problem

• Understand the Symptoms: What exactly is the issue? Is it a Pod stuck in Pending state, a service not reachable, or a resource over-utilization?

• Gather Context:

  • What is the impacted resource? (e.g., Pod, Service, Node, etc.)

  • When did the issue start, and what events led to it?

  • Are multiple resources or components affected?

2. Check Resource Status

• Use kubectl to inspect the status of affected resources:

  kubectl get pods

  kubectl get services

  kubectl get deployments

  kubectl get nodes

• Examine detailed information about the problematic resource:

  kubectl describe pod <pod-name>

  3. Inspect Events

  • Check for recent events that may indicate the cause:

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

  • Look for errors like FailedScheduling, FailedMount, or CrashLoopBackOff.

  4. Analyze Logs

  • Inspect logs of the affected Pods to identify application-specific or runtime errors:

    kubectl logs <pod-name>

  • For multi-container Pods, specify the container name:

    kubectl logs <pod-name> -c <container-name>

  • If logs are missing or incomplete, check log collection tools like Fluentd or ELK Stack (if configured).

  5. Use Debugging Tools

  • Access the Pod Environment:

    Start an interactive shell session in the Pod to debug:

    kubectl exec -it <pod-name> -- /bin/sh

  • Debug YAML Configuration:

    Export the YAML definition to inspect configuration details

    kubectl get pod <pod-name> -o yaml

  6. Validate Resource Specifications

  • Check for common misconfigurations in YAML files:

    • Incorrect image names or tags.

    • Missing resources.requests or resources.limits.

    • Improperly configured readinessProbe or livenessProbe.

  • Use validation tools:

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

  7. Verify Networking

  • Test connectivity between Pods and Services:

    • Use ping, curl, or wget inside the Pod.

  • Check DNS resolution

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

  • Inspect Service and Endpoint configuration:

    kubectl get svc kubectl describe svc <service-name>

    kubectl get endpoints <service-name>

  8. Investigate Node and Cluster Health

  • Check Node health and readiness:

    kubectl get nodes kubectl describe node <node-name>

  • Look for DiskPressure, MemoryPressure, or PIDPressure.

  • Verify control plane components:

    kubectl get componentstatuses

  • Inspect kubelet logs on the affected node:

    journalctl -u kubelet

  9. Review Role-Based Access Control (RBAC)

  • Ensure the required permissions are granted to the relevant users, service accounts, or resources:

    kubectl auth can-i <verb> <resource> --as <user>

  • Check roles and bindings:

    kubectl get roles,rolebindings

  10. Monitor Resource Usage

  • Check resource consumption to ensure requests and limits are appropriate:

    kubectl top nodes

    kubectl top pods

  • Adjust resources.requests and resources.limits in the Pod specification if necessary.

  11. Validate Dependencies

  • Confirm that all dependencies (e.g., Persistent Volumes, ConfigMaps, Secrets) are available and properly configured:

    kubectl get pvc

    kubectl get configmap

    kubectl get secret

  12. Examine Cluster Configuration

  • Check for version compatibility between Kubernetes components (API server, kubelet, etc.).

  • Ensure proper configuration of kube-proxy, networking plugins, and cloud-provider integration.

  13. Look for Known Issues

  • Search Kubernetes documentation, forums, and GitHub issues for known bugs or fixes.

  • Use troubleshooting tools or plugins like:

    • k9s: A terminal-based UI for managing Kubernetes resources.

    • kubectl debug (if supported): Start a debug container for deeper analysis.

  14. Test Resolution in Staging

  • Before applying fixes to production, replicate the issue in a staging environment and validate your solution.

  15. Escalate or Seek Community Help

  • If the issue persists, engage with:

    • Kubernetes Slack or forums.

    • Kubernetes GitHub repository for bug reporting.

    • Vendor-specific support if using a managed Kubernetes service.