Helm Generator

Helm Chart Generator

Overview

Generate production-ready Helm charts with best practices built-in. Create complete charts or individual resources with standard helpers, proper templating, and automatic validation.

Official Documentation:

• Helm Docs - Main documentation
• Chart Best Practices - Official best practices guide
• Template Functions - Built-in functions
• Sprig Functions - Extended function library

When to Use This Skill

Trigger phrases: "create", "generate", "build", "scaffold" Helm charts/templates

Chart Generation Workflow

Stage 1: Understand Requirements

Gather information about:

• Scope: Full chart, specific resources, or manifest conversion
• Application: Name, image, ports, env vars, resources, scaling, storage
• CRDs/Operators: cert-manager, Prometheus Operator, Istio, etc.
• Security: RBAC, security contexts, network policies

REQUIRED: Use AskUserQuestion if any of these are missing or ambiguous:

Do NOT assume values for critical settings. Ask first, then proceed.

Stage 2: CRD Documentation Lookup

If custom resources are needed:

1. Try context7 MCP first:

   mcp__context7__resolve-library-id with operator name
   mcp__context7__get-library-docs with topic for CRD kind
   

2. Fallback to WebSearch:

   "<operator>" "<CRD-kind>" "<version>" kubernetes documentation spec
   

See references/crd_patterns.md for common CRD examples.

Stage 3: Create Chart Structure

Use the scaffolding script:

bash scripts/generate_chart_structure.sh <chart-name> <output-directory> [options]

Script options:

• --image <repo> - Image repository (default: nginx). Note: Pass only the repository name without tag (e.g., redis not redis:7-alpine)
• --port <number> - Service port (default: 80)
• --type <type> - Workload type: deployment, statefulset, daemonset (default: deployment)
• --with-templates - Generate resource templates (deployment.yaml, service.yaml, etc.)
• --with-ingress - Include ingress template
• --with-hpa - Include HPA template
• --force - Overwrite existing chart without prompting

Important customization notes:

• The script uses http as the default port name in templates. Customize port names for non-HTTP services (e.g., redis, mysql, grpc)
• Templates include checksum annotations for ConfigMap/Secret changes (conditionally enabled via .Values.configMap.enabled and .Values.secret.enabled)

Standard structure:

mychart/
  Chart.yaml           # Chart metadata (apiVersion: v2)
  values.yaml          # Default configuration
  values.schema.json   # Optional: JSON Schema validation
  templates/
    _helpers.tpl       # Standard helpers (ALWAYS create)
    NOTES.txt          # Post-install notes
    deployment.yaml    # Workloads
    service.yaml       # Services
    ingress.yaml       # Ingress (conditional)
    configmap.yaml     # ConfigMaps
    serviceaccount.yaml # RBAC
  .helmignore          # Ignore patterns

Stage 4: Generate Standard Helpers

Use the helpers script or assets/_helpers-template.tpl:

bash scripts/generate_standard_helpers.sh <chart-name> <chart-directory>

Required helpers: name, fullname, chart, labels, selectorLabels, serviceAccountName

Stage 5: Generate Templates

⚠️ CRITICAL REQUIREMENT: Read Reference Files NOW

You MUST use the Read tool to load these reference files at this stage, even if you read them earlier in the conversation:

1. Read references/resource_templates.md - for the specific resource type patterns
2. Read references/helm_template_functions.md - for template function usage
3. Read references/crd_patterns.md - if generating CRD resources (ServiceMonitor, Certificate, etc.)

Why: Prior context may be incomplete or summarized. Reading reference files at generation time guarantees all patterns, functions, and examples are available for accurate template creation.

Do NOT skip this step. Template quality depends on having current reference patterns loaded.

Reference templates for all resource types in references/resource_templates.md:

• Workloads: Deployment, StatefulSet, DaemonSet, Job, CronJob
• Services: Service, Ingress
• Config: ConfigMap, Secret
• RBAC: ServiceAccount, Role, RoleBinding, ClusterRole, ClusterRoleBinding
• Network: NetworkPolicy
• Autoscaling: HPA, PodDisruptionBudget

Key patterns (MUST include in all templates):

# Use helpers for names and labels
metadata:
  name: {{ include "mychart.fullname" . }}
  labels: {{- include "mychart.labels" . | nindent 4 }}

# Conditional sections with 'with'
{{- with .Values.nodeSelector }}
nodeSelector: {{- toYaml . | nindent 2 }}
{{- end }}

# Config change restart trigger (ALWAYS add to workloads)
annotations:
  checksum/config: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}

Checksum annotation is REQUIRED for Deployments/StatefulSets/DaemonSets to trigger pod restarts when ConfigMaps or Secrets change. Add conditionally if ConfigMap is optional:

{{- if .Values.configMap.enabled }}
checksum/config: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}
{{- end }}

Stage 6: Create values.yaml

Structure guidelines:

• Group related settings logically
• Document every value with # -- comments
• Provide sensible defaults
• Include security contexts, resource limits, probes

See assets/values-schema-template.json for JSON Schema validation.

Stage 7: Validate

ALWAYS validate using devops-skills:helm-validator skill:

1. helm lint
2. helm template (render check)
3. YAML/schema validation
4. Dry-run if cluster available

Fix issues and re-validate until all checks pass.

Template Functions Quick Reference

See references/helm_template_functions.md for complete guide.

Conditional patterns:

{{- if .Values.enabled }}...{{- end }}
{{- if not .Values.autoscaling.enabled }}replicas: {{ .Values.replicaCount }}{{- end }}

Iteration:

{{- range .Values.items }}
- {{ . }}
{{- end }}

Working with CRDs

See references/crd_patterns.md for complete examples.

Key points:

• CRDs you ship → crds/ directory (not templated, not deleted on uninstall)
• CR instances → templates/ directory (fully templated)
• Always lookup documentation for CRD spec requirements
• Document operator dependencies in Chart.yaml annotations

Converting Manifests to Helm

1. Parameterize: Names → helpers, values → values.yaml
2. Apply patterns: Labels, conditionals, toYaml for complex objects
3. Add helpers: Create _helpers.tpl with standard helpers
4. Validate: Use devops-skills:helm-validator, test with different values

Error Handling

Resources

Scripts

References

Assets

Integration with devops-skills:helm-validator

After generating charts, automatically invoke devops-skills:helm-validator to ensure quality:

1. Generate chart/templates
2. Invoke devops-skills:helm-validator skill
3. Fix identified issues
4. Re-validate until passing