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Zhongwei Li
2025-11-28 15:21:09 +08:00
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{
"name": "devops",
"description": "devops skills such as generate Helm chart, Terraform script, CI/CD pipeline, GitOps, Docker.",
"version": "2.0.1",
"author": {
"name": "Truong Vu",
"email": "vukhanhtruong@gmail.com"
}
}

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---
name: helm-scaffold
description: Generate production-ready Helm charts for Kubernetes applications. Use when users need to create new Helm charts, convert Kubernetes manifests to Helm templates, scaffold charts for Deployments/StatefulSets/Jobs/CronJobs, create multi-environment configurations, or standardize organizational chart templates with CNCF/Helm best practices. Uses Python scaffolding script and template assets for automated generation.
---
# Helm Scaffold
Automate production-ready Helm chart generation using template assets, Python scaffolding scripts, and Kubernetes best practices through conversational interaction.
## Core Capabilities
- **Automated scaffolding** using Python script (`scripts/scaffold_chart.py`)
- **Template-based generation** from `assets/templates/` directory
- **Convert Kubernetes manifests** to Helm templates
- **Multi-environment configurations** (dev, staging, prod)
- **Organizational standardization** with team policies
- **Comprehensive testing** with dry-run workflows
## Quick Start
For simple chart generation, use the Python scaffolding script directly:
```bash
python3 scripts/scaffold_chart.py <chart-name> \
--workload-type deployment \
--output /mnt/user-data/outputs \
--ingress \
--hpa
```
## Workflow Decision Tree
```
User Request
├─ Simple chart (name + type provided)
│ └─ Use scaffold_chart.py directly
├─ Complex chart (many options)
│ └─ Ask clarifying questions, then use scaffold_chart.py
├─ Manifest conversion
│ └─ Manual templatization process
└─ Custom requirements
└─ Manual generation with template references
```
## Interactive Workflow
### Step 1: Understand Use Case
Identify the scenario:
- **Simple new chart**: Use `scaffold_chart.py` with user-provided params
- **Complex chart**: Ask questions, build command
- **Manifest conversion**: Extract variables, templatize
- **Team template**: Apply organizational standards
### Step 2: Gather Requirements
**Minimum required:**
- Chart name
- Workload type (deployment, statefulset, job, cronjob)
**Optional (ask if not provided):**
- Container image repository and tag
- Application port
- Include Ingress? (--ingress flag)
- Include HPA? (--hpa flag)
- Include ConfigMap? (--configmap flag)
- Multi-environment configs?
### Step 3: Generate Chart
#### Option A: Using scaffold_chart.py (Recommended)
For straightforward charts, execute the Python script:
```python
import subprocess
cmd = [
'python3', 'scripts/scaffold_chart.py',
chart_name,
'--workload-type', workload_type,
'--output', '/mnt/user-data/outputs'
]
if include_ingress:
cmd.append('--ingress')
if include_hpa:
cmd.append('--hpa')
if include_configmap:
cmd.append('--configmap')
subprocess.run(cmd, check=True)
```
**The script automatically:**
- Creates chart directory structure
- Copies template files from `assets/templates/`
- Replaces `CHARTNAME` placeholder with actual chart name
- Includes only requested resources
- Applies best practices
#### Option B: Manual Generation
For custom requirements, manually copy and modify templates:
1. Read template from `assets/templates/<workload>/<file>.yaml`
2. Replace `CHARTNAME` with actual chart name
3. Customize based on user requirements
4. Write to `/home/claude/<chart-name>/templates/`
### Step 4: Multi-Environment Configuration
If user requests dev/staging/prod configs, create additional values files:
**values-dev.yaml:**
```yaml
replicaCount: 1
resources:
limits: {cpu: 200m, memory: 128Mi}
requests: {cpu: 25m, memory: 32Mi}
env:
- name: LOG_LEVEL
value: "debug"
```
**values-prod.yaml:**
```yaml
replicaCount: 3
resources:
limits: {cpu: 1000m, memory: 512Mi}
requests: {cpu: 100m, memory: 128Mi}
autoscaling:
enabled: true
minReplicas: 3
maxReplicas: 10
```
### Step 5: Testing Instructions
**Always provide comprehensive testing workflow:**
```bash
# Navigate to chart directory
cd <chart-name>
# 1. Validate chart structure
helm lint .
# 2. Render templates locally
helm template <chart-name> .
# 3. Dry run installation
helm install <chart-name> . --dry-run --debug
# 4. Test with specific values
helm template <chart-name> . -f values-dev.yaml
# 5. Deploy to test namespace
kubectl create namespace test
helm install <chart-name> . -n test
# 6. Verify deployment
kubectl get all -n test
helm status <chart-name> -n test
# 7. Cleanup
helm uninstall <chart-name> -n test
kubectl delete namespace test
```
### Step 6: Deliver Output
- Chart is created in `/mnt/user-data/outputs/<chart-name>/`
- Provide download link
- Include testing instructions
- Explain customization options
## Workload Types
Load `references/workload-types.md` for detailed decision tree and characteristics.
**Quick reference:**
- **Deployment**: Stateless apps (web, API, microservices)
- **StatefulSet**: Stateful apps (databases, caches) - stable IDs, persistent storage
- **Job**: One-time tasks (migrations, ETL)
- **CronJob**: Scheduled tasks (backups, reports)
**Template locations:**
- `assets/templates/deployment/deployment.yaml`
- `assets/templates/statefulset/statefulset.yaml`
- `assets/templates/job/job.yaml`
- `assets/templates/cronjob/cronjob.yaml`
## Converting Manifests to Helm
When user provides raw Kubernetes YAML:
1. **Analyze manifests**: Identify resources and configurable values
2. **Extract variables**: Images, replicas, ports, resources, env-specific settings
3. **Create values.yaml**: Organize extracted values logically
4. **Templatize YAML**:
- Replace hardcoded values with `{{ .Values.* }}`
- Use `{{ include "CHARTNAME.fullname" . }}` for names
- Use `{{ include "CHARTNAME.labels" . }}` for labels
5. **Add helpers**: Copy `assets/templates/_helpers.tpl` and customize
6. **Document**: Explain what was parameterized
## Template Assets Structure
```
assets/templates/
├── Chart.yaml # Base chart metadata
├── values.yaml # Complete values with all options
├── .helmignore # Files to ignore
├── _helpers.tpl # Helper functions (CHARTNAME placeholder)
├── NOTES.txt # Post-install instructions
├── deployment/
│ └── deployment.yaml # Deployment template
├── statefulset/
│ └── statefulset.yaml # StatefulSet template
├── job/
│ └── job.yaml # Job template
├── cronjob/
│ └── cronjob.yaml # CronJob template
├── service/
│ └── service.yaml # Service template
├── ingress/
│ └── ingress.yaml # Ingress template
├── hpa/
│ └── hpa.yaml # HPA template
├── configmap/
│ └── configmap.yaml # ConfigMap template
└── rbac/
└── serviceaccount.yaml # ServiceAccount template
```
All templates use `CHARTNAME` placeholder which is replaced by the script.
## Scripts
### scaffold_chart.py
**Purpose**: Automated chart generation from templates
**Usage**:
```bash
python3 scripts/scaffold_chart.py CHART_NAME [OPTIONS]
Arguments:
CHART_NAME Name of the Helm chart
Options:
-w, --workload-type Type: deployment, statefulset, job, cronjob (default: deployment)
-o, --output Output directory (default: current directory)
--ingress Include Ingress resource
--hpa Include HorizontalPodAutoscaler
--configmap Include ConfigMap
```
**What it does:**
- Creates chart directory structure
- Copies relevant templates from `assets/templates/`
- Replaces `CHARTNAME` placeholder
- Includes only requested optional resources
- Applies best practices automatically
## Best Practices (Auto-Applied)
The templates in `assets/templates/` already include:
- ✅ Standard Kubernetes labels (`app.kubernetes.io/*`)
- ✅ Security contexts (readOnlyRootFilesystem, runAsNonRoot, dropped capabilities)
- ✅ Resource limits and requests
- ✅ Health checks (liveness and readiness probes)
- ✅ Helper functions for naming and labels
- ✅ Proper selector labels
- ✅ Service account configuration
## Organizational Standardization
For platform teams needing consistent charts:
1. **Capture standards**: Ask about required labels, policies, security requirements
2. **Modify templates**: Update `assets/templates/_helpers.tpl` with org labels
3. **Generate**: Use scaffold_chart.py with modified templates
4. **Document**: Explain customization points
Example org-specific helper addition:
```yaml
{{- define "CHARTNAME.orgLabels" -}}
org.example.com/cost-center: {{ .Values.org.costCenter | required "Cost center required" }}
org.example.com/team: {{ .Values.org.team | required "Team name required" }}
{{- end }}
```
## Success Criteria
Generated charts must:
- ✅ Pass `helm lint` without errors (95%+ target)
- ✅ Follow CNCF/Helm best practices
- ✅ Include security contexts by default
- ✅ Have resource limits configured
- ✅ Use standard Kubernetes labels
- ✅ Be deployment-ready within <15 minutes
## References
Load as needed based on use case:
**For workload selection:**
- `references/workload-types.md` - Decision tree, characteristics, when to use each type
**For testing:**
- `references/testing-guide.md` - Comprehensive dry-run workflows, mock values, validation commands
**For best practices:**
- `references/best-practices.md` - CNCF/Helm standards, security guidelines
**For examples:**
- `references/examples.md` - Real-world chart scenarios
**For template reference:**
- `references/templates.md` - Inline template documentation
## Example Usage
### Example 1: Simple Web App
```
User: "Create a Helm chart for my Node.js API"
Claude: I'll create a chart for your Node.js API. A few quick questions:
1. What's the chart name? (e.g., "user-api")
2. What's your container image? (e.g., "myorg/user-api:1.0.0")
3. Do you need an Ingress? (yes/no)
User: Name is user-api, image is myorg/user-api:1.0.0, yes to ingress
Claude: [Executes]
python3 scripts/scaffold_chart.py user-api \
--workload-type deployment \
--output /mnt/user-data/outputs \
--ingress
[Chart generated successfully]
[Provides testing instructions]
```
### Example 2: Database
```
User: "Create a Helm chart for PostgreSQL with persistent storage"
Claude: I'll create a StatefulSet chart for PostgreSQL.
What storage size do you need? (e.g., 10Gi, 20Gi)
User: 20Gi
Claude: [Executes]
python3 scripts/scaffold_chart.py postgresql \
--workload-type statefulset \
--output /mnt/user-data/outputs
[Then manually adds persistence config to values.yaml]
persistence:
enabled: true
size: 20Gi
storageClass: standard
```
### Example 3: Scheduled Backup
```
User: "Create a CronJob chart for nightly backups"
Claude: [Executes]
python3 scripts/scaffold_chart.py db-backup \
--workload-type cronjob \
--output /mnt/user-data/outputs
[Then updates values.yaml with schedule]
cronjob:
schedule: "0 2 * * *"
```
## Troubleshooting
**Issue**: Script fails to find templates
**Solution**: Ensure running from skill directory or provide full path to script
**Issue**: CHARTNAME not replaced
**Solution**: Script automatically handles this; if manual, use find/replace
**Issue**: Generated chart fails lint
**Solution**: Check values.yaml for required fields, review templates
## Notes
- Always use `scaffold_chart.py` when possible - it's faster and consistent
- Templates use `CHARTNAME` placeholder - script replaces automatically
- For complex customization, read templates from assets and modify manually
- Multi-environment configs are created separately after initial generation
- Testing instructions are critical - always include them