k3s-gitops/apps/demo-nginx/docs/ROLLBACK_QUICK_REF.md

🔄 Manual Rollback - Quick Reference

🚀 Quick Start (2 minutes)

Jenkins → demo-nginx-rollback → Build with Parameters

ROLLBACK_METHOD: IMAGE_TAG
TARGET_VERSION: main-21
SKIP_HEALTH_CHECK: true (recommended!)
DRY_RUN: false

→ Build → ✅ SUCCESS!

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📋 3 Ways to Rollback

1. By Image Tag (Fastest)

Method: IMAGE_TAG
Target: main-21
Use: When you know the build number

2. By Revision Number

Method: REVISION_NUMBER
Target: 2
Use: Rollback N steps back
Find: kubectl rollout history deployment/demo-nginx -n demo-app

3. By Git Commit

Method: GIT_COMMIT
Target: abc123def
Use: Exact code state
Find: git log --oneline apps/demo-nginx/deployment.yaml

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⚡ Emergency Rollback (30 seconds)

# Fastest - kubectl
kubectl rollout undo deployment/demo-nginx -n demo-app

# To specific revision
kubectl rollout undo deployment/demo-nginx -n demo-app --to-revision=25

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🔍 Verify Rollback

# Check image
kubectl get deployment demo-nginx -n demo-app \
  -o jsonpath='{.spec.template.spec.containers[0].image}'

# Check pods
kubectl get pods -n demo-app -l app=demo-nginx

# Test health
POD=$(kubectl get pods -n demo-app -l app=demo-nginx -o jsonpath='{.items[0].metadata.name}')
kubectl exec $POD -n demo-app -- wget -q -O- http://localhost/health

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⚙️ Parameters

Parameter	Default	Recommended
ROLLBACK_METHOD	IMAGE_TAG	IMAGE_TAG
TARGET_VERSION	(required)	main-21
SKIP_HEALTH_CHECK	false	true
DRY_RUN	false	false

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🐛 Common Issues - FIXED

Issue	Fix	Status
Wrong container name	Use nginx	✅ Fixed
Whitespace in input	Auto-trim	✅ Fixed
RBAC permission	Added pods/exec	✅ Fixed
Health check timing	Use SKIP_HEALTH_CHECK	⚠️ Workaround
Bash loop broken	Use 1 2 3 4 5	✅ Fixed

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💡 Best Practices

1. ✅ Always test with DRY_RUN: true first
2. ✅ Use SKIP_HEALTH_CHECK: true for faster rollback
3. ✅ Verify manually after rollback (30-60s wait)
4. ✅ Document rollback reason in Jenkins build comment
5. ✅ Check ArgoCD sync status after rollback

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📊 Verification Commands

# Full status check
kubectl get deployment demo-nginx -n demo-app
kubectl get pods -n demo-app -l app=demo-nginx
kubectl rollout history deployment/demo-nginx -n demo-app

# Watch pods update
watch kubectl get pods -n demo-app

# Check logs
kubectl logs -n demo-app -l app=demo-nginx --tail=50

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🎯 Success Checklist

• Jenkins pipeline exists (demo-nginx-rollback)
• RBAC configured (pods/exec permission)
• Target version identified
• DRY_RUN tested
• Rollback executed
• Pods verified (Running)
• Image version confirmed
• Health check passed (manual)
• ArgoCD synced

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📚 Full Documentation

See: apps/demo-nginx/docs/ROLLBACK_MANUAL.md

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Quick Reference - Keep this handy! 📌