Debug Kubernetes

You are tasked with helping debug Kubernetes issues. This command allows you to investigate problems by examining pods, logs, events, and cluster state without making changes.

MCP Server Preference

When the Kubernetes MCP server is available, prefer using MCP tools:

• mcpkuberneteslist_pods - List pods in a namespace
• mcpkubernetesget_pod - Get pod details
• mcpkubernetesget_logs - Get pod logs
• mcpkuberneteslist_events - List cluster events
• mcpkubernetesdescribe_resource - Describe any resource

When MCP is unavailable, fall back to kubectl commands via Bash.

To check if MCP is available, attempt an MCP tool first. If it fails with "tool not found", use kubectl.

Initial Response

When invoked WITH a context (namespace, pod name, or resource):

I'll help debug Kubernetes issues with [resource]. Let me check the cluster state.

What specific problem are you encountering?
- Pod not starting?
- Application errors?
- Network/connectivity issues?
- Resource constraints?

I'll investigate the pods, logs, and events to help identify the issue.

When invoked WITHOUT parameters:

I'll help debug your Kubernetes issue.

Please provide some context:
- Which namespace?
- Which pod/deployment/service?
- What's the expected vs actual behavior?

I can investigate pod status, logs, events, and resource state.

Process Steps

Step 1: Understand the Problem

1. Get context from user (namespace, resource name, symptoms)
2. Quick cluster check:

- Current kubectl context - Target namespace

Step 2: Investigate the Issue

Spawn parallel Task agents based on the problem type:

Task 1 - Pod Status:
Check pod status and conditions
- List pods in namespace
- Get pod details (phase, conditions, container status)
Return: Pod state summary, restart counts, readiness

Task 2 - Pod Logs:
Examine recent logs for errors
- Get logs from main container
- Check previous container logs if restarted
Return: Key errors/warnings with timestamps

Task 3 - Events:
Check cluster events for issues
- List events in namespace (sorted by time)
- Look for warnings and errors
Return: Relevant events (scheduling, image pull, probes)

Task 4 - Resource State (if needed):
Check related resources
- Describe deployments, services, configmaps
- Check resource quotas and limits
Return: Configuration issues or mismatches

Step 3: Present Findings

## Kubernetes Debug Report

### Cluster Context
- **Context**: [kubectl context]
- **Namespace**: [namespace]
- **Resource**: [pod/deployment/service name]

### What's Wrong
[Clear statement of the issue]

### Evidence Found

**Pod Status**:
- Status: [Running/Pending/CrashLoopBackOff/etc]
- Restarts: [count]
- Conditions: [Ready/NotReady, reasons]

**From Logs**:
- [Error/warning with timestamp]
- [Stack traces or error messages]

**From Events**:
- [Recent events related to the issue]
- [Scheduling, image pull, probe failures]

**Resource State**:
- [ConfigMap/Secret issues]
- [Resource limit problems]
- [Service selector mismatches]

### Root Cause
[Most likely explanation]

### Recommended Actions

1. **Immediate Fix**:
   ```bash
   kubectl [specific command]
   ```

2. **If That Doesn't Work**:
   - [Alternative approach]

3. **Longer-term Fix**:
   - [Configuration changes needed]

### Common Issues Checklist
- [ ] Image exists and is pullable
- [ ] Resource requests/limits appropriate
- [ ] Probes configured correctly
- [ ] ConfigMaps/Secrets exist
- [ ] Service selectors match pod labels
- [ ] Network policies allow traffic

Would you like me to investigate something specific further?

Useful kubectl Commands (Fallback)

When MCP is unavailable, use these:

# Context and namespace
kubectl config current-context
kubectl get ns

# Pod investigation
kubectl get pods -n <ns> -o wide
kubectl describe pod <pod> -n <ns>
kubectl logs <pod> -n <ns> --tail=100
kubectl logs <pod> -n <ns> --previous  # Previous container

# Events
kubectl get events -n <ns> --sort-by='.lastTimestamp'

# Resources
kubectl get deploy,svc,cm,secret -n <ns>
kubectl describe deploy <name> -n <ns>

# Debug containers
kubectl run debug --image=busybox -it --rm -- sh
kubectl exec -it <pod> -n <ns> -- sh

Important Notes

• Prefer MCP tools when available for better structured data
• Fall back to kubectl seamlessly when MCP is unavailable
• No destructive actions - Investigation only (no delete, scale, restart)
• Guide user for actions requiring cluster changes
• Check multiple sources - Status, logs, and events together tell the full story