troubleshoot

Kubernetes Troubleshoot

Automatically diagnose common Kubernetes issues.

Trigger Phrases

• "왜 안돼", "왜 안되지", "pod가 죽어", "에러나"
• "troubleshoot", "debug", "diagnose"
• "CrashLoopBackOff", "ImagePullBackOff", "Pending", "Error"

Diagnostic Flow

1. Get Pod Status

export KUBECONFIG=$HOME/.kube/config.home
kubectl get pods -n <namespace> <pod-name> -o wide

2. Check Events

kubectl describe pod -n <namespace> <pod-name> | grep -A 20 "Events:"

3. Get Logs

# Current container
kubectl logs -n <namespace> <pod-name> --tail=100

# Previous container (if restarting)
kubectl logs -n <namespace> <pod-name> --previous --tail=100

# All containers in pod
kubectl logs -n <namespace> <pod-name> --all-containers=true --tail=50

4. Check Resource Status

# Node resources
kubectl top nodes

# Pod resources
kubectl top pods -n <namespace>

# PVC status
kubectl get pvc -n <namespace>

Common Issues & Solutions

CrashLoopBackOff

1. Check logs for application errors
2. Verify environment variables (Infisical secrets mounted?)
3. Check resource limits (OOMKilled?)
4. Validate startup/liveness probes

ImagePullBackOff

1. Verify image name and tag
2. Check imagePullSecrets configured
3. Test registry connectivity
4. Confirm image exists in registry

Pending

1. Check node resources (CPU/Memory)
2. Verify nodeSelector/affinity matches
3. Check PVC binding status
4. Review taints/tolerations

OOMKilled

1. Increase memory limits
2. Check for memory leaks in application
3. Review JVM heap settings (if Java)

GPU Issues

# Check GPU operator
kubectl get pods -n gpu-operator

# Check device plugin
kubectl logs -n gpu-operator -l app=nvidia-device-plugin-daemonset --tail=50

# Check GPU allocation
kubectl describe node | grep -A 5 "nvidia.com/gpu"

ArgoCD Sync Issues

# App status
argocd app get <app-name>

# Sync details
argocd app sync <app-name> --dry-run

# Resource diff
argocd app diff <app-name>

# Force refresh
argocd app get <app-name> --refresh

Output Format

Provide diagnosis in this format:

## Issue Summary
[Brief description of the problem]

## Root Cause
[Identified cause with evidence]

## Solution
[Step-by-step fix]

## Prevention
[How to avoid this in the future]

Reference

• @.claude/rules/kubernetes.md
• @.claude/rules/argocd-apps.md