troubleshoot

name	troubleshoot
description	Diagnoses Kubernetes pod issues automatically. Use when pods are in CrashLoopBackOff, ImagePullBackOff, Pending, or Error state. Analyzes events, logs, and resource status to identify root causes.
allowed-tools	Bash, Read, Grep, Glob

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