Kubernetes Troubleshooting: Real-World Production Fixes

Diagnose kubernetes crash loop back off by identifying causes like non-zero exit codes and resource limits, and apply fixes using kubectl logs, describe, and exponential backoff.

Diagnose image pull back off by identifying wrong image tags and registry access issues, then fix with correct tag and image pull secrets for a private registry.

Demonstrates real-world Kubernetes pod troubleshooting by reproducing pending pods caused by oversized memory requests, taints and tolerations, node selectors, and PVCs, and shows practical fixes in development and production environments.

Identify why pods stay terminating, including graceful shutdown and pre-stop hook issues. Troubleshoot with kubectl describe and logs, and check PDBs and PVCs.

Discover how Kubernetes gracefully shuts down pods and why they enter terminating state. Explore termination grace period seconds, pre-stop, and finalizers, and how to resolve stuck pods.

Troubleshoot Kubernetes deployment rollouts by diagnosing readiness probe issues, rolling update settings, and init container failures to restore healthy replica sets and timely releases.

Explore how to fix a deployment rollout stuck by correcting readiness path and rolling strategy, address readiness probe failures pointing to healthz, and resolve init container crashes that halt progress.

Diagnose and fix init containers in Kubernetes to prevent startup delays and crashes. Explore scenarios—migration failures, volume mount mismatches, and network policy blocks—and apply fixes like init hyphen fix.

Explore real-world Kubernetes troubleshooting with init containers failing. Learn to fix by aligning init and app volumes and mount paths and by resolving network policy blocks causing curl to fail.

Learn how readiness and liveness probes govern pod health in Kubernetes, what happens on probe failures, and how to diagnose them using kubectl and probe configurations.

Demonstrates debugging startup, readiness, and liveness probes in Kubernetes, showing how startup probes and adjusted timings align app startup with health checks.

Learn how to diagnose and fix service has no endpoints by verifying service selectors match pod labels, ports align, and namespaces, using kubectl get endpoints and related checks.

Diagnose and fix Kubernetes service misconfigurations by checking selectors, endpoints, and target ports; resolve issues across namespace mismatches and endpoint slices using kubectl commands.

Troubleshoot dns failures in Kubernetes by diagnosing core dns health, misconfigurations, or blocked dns traffic, using pod-based checks, network policies, and logs to restore service discovery and connectivity.

Diagnose and fix Kubernetes DNS failures by testing CoreDNS access from a sandbox pod, evaluating network policies, and ensuring egress to DNS port 53 is allowed.

Explore how Kubernetes network policies control pod traffic with default deny rules, test scenarios for ingress and egress, and resolve with namespace labels and allow rules.

Troubleshoot Kubernetes ingress 404s and TLS errors by inspecting ingress resources, controllers, host/path rules, TLS secrets, and service endpoints to resolve routing issues.

Learn to troubleshoot Kubernetes ingress using Minikube by mapping the ingress to the correct service port, verifying endpoints, and correcting host header rules to resolve 404, 502, and 503 errors.

Explore troubleshooting memory limits in Kubernetes: trigger OOMKilled, observe crash loops, and fix by increasing memory limits (512Mi) and using kubectl top with metrics server.

Evicting pods under node resource pressure protects stability by addressing memory, disk, ephemeral storage, and PID limits, while Prometheus alerts and kubectl help diagnose and prevent churn.

Explore how Kubernetes evicts pods at the node level under disk and memory pressure, how to fix evictions with PVCs or larger storage, and distinguish eviction from OOM kills.

Explore lab troubleshooting of horizontal pod autoscaler, from over provisioning to proper CPU requests, through a live minikube demo using Kubernetes deploy YAMLs and HPA settings.

Troubleshoot PVC PV failures in Kubernetes by addressing missing storage classes, unsupported access modes, and binding mode wait for first customer, then resolve with storage class fixes and PVC edits.

Explore how create container config error arises in Kubernetes when configuration injections fail due to missing or misconfigured config maps, secrets, or volumes, leaving pods in error or pending.

Troubleshoot Kubernetes config maps and secrets, diagnose container config errors caused by missing or misnamed keys, and ensure resources exist in the correct namespace.

Explore Kubernetes rbac by creating a dev-user service account, applying role bindings to grant get, list, watch on parts, and using cluster roles for cluster-wide access.

Mastering resource quotas and limit ranges in kubernetes for multi-tenant clusters, diagnosing quota exceedance using replica sets, and fixing deployments by adjusting CPU and memory limits within namespace constraints.