helm-generator

Helm Chart Generator

Overview

Generate production-ready Helm charts with deterministic scaffolding, standard helpers, reusable templates, and validation loops.

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

Use this skill when prompts include phrases like:

• "create Helm chart"
• "scaffold Helm chart"
• "generate Helm templates"
• "convert manifests to Helm chart"
• "build chart with Deployment/Service/Ingress"

Execution Flow

Follow these stages in order. Do not skip required stages.

Stage 1: Gather Requirements (Required)

Collect:

• Scope: full chart, specific templates, or conversion from manifests
• Workload: deployment, statefulset, or daemonset
• Image reference: repository, optional tag, or digest
• Ports: service port and container target port (separate values)
• Runtime settings: resources, probes, autoscaling, ingress, storage
• Security: service account, security contexts, optional RBAC/network policies

Use request_user_input when critical fields are missing.

If request_user_input is unavailable, ask in normal chat and continue with explicit assumptions.

Do not silently assume critical settings.

Stage 2: Lookup CRD Documentation (Only if CRDs Are In Scope)

1. Try Context7 first:

• mcp__context7__resolve-library-id
• mcp__context7__query-docs

1. Fallback chain if Context7 is unavailable or incomplete:

• Operator official docs (preferred)
• General web search

Also consult references/crd_patterns.md for example patterns.

Stage 3: Scaffold Chart Structure (Required)

Run:

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

Options:

• --image <repo> - Supports repo-only, tagged image, registry ports, and digest refs
• --port <number> - Service port (default: 80)
• --target-port <number> - Container target port (default: 8080)
• --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

Image parsing behavior:

• --image nginx:1.27 -> repository nginx, tag 1.27
• --image registry.local:5000/team/app -> repository kept intact
• --image ghcr.io/org/app@sha256:... -> digest mode (no tag concatenation)
• --tag cannot be combined with digest image references

Idempotency and overwrite behavior:

• generate_chart_structure.sh: prompts before overwrite; --force overwrites non-interactively.
• generate_standard_helpers.sh: prompts before replacing templates/_helpers.tpl; --force bypasses prompt.

Expected scaffold shape:

mychart/
  Chart.yaml
  values.yaml
  templates/
    _helpers.tpl
    NOTES.txt
    serviceaccount.yaml
    service.yaml
    configmap.yaml
    secret.yaml
    deployment.yaml|statefulset.yaml|daemonset.yaml
    ingress.yaml (optional)
    hpa.yaml (optional)
  .helmignore

Stage 4: Generate Standard Helpers

Run:

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

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

Fallback:

• If script execution is blocked, copy assets/_helpers-template.tpl and replace CHARTNAME with the chart name.

Stage 5: Consult References and Generate Templates (Required)

Consult relevant references once at this stage:

• references/resource_templates.md for the resource patterns being generated
• references/helm_template_functions.md for templating function usage
• references/crd_patterns.md only when CRDs are in scope

Example file-open commands:

sed -n '1,220p' references/resource_templates.md
sed -n '1,220p' references/helm_template_functions.md

Resource coverage from 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

Required template patterns:

metadata:
  name: {{ include "mychart.fullname" . }}
  labels: {{- include "mychart.labels" . | nindent 4 }}

{{- with .Values.nodeSelector }}
nodeSelector: {{- toYaml . | nindent 2 }}
{{- end }}

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

Checksum annotations are required for workloads, but must be conditional and only reference generated templates (configmap.yaml, secret.yaml).

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
• Keep service.port and service.targetPort separate and explicit
• Keep configMap.enabled / secret.enabled aligned with generated templates

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

Stage 7: Validate

Preferred path: run the helm-validator skill.

If skill invocation is unavailable, run local commands directly:

helm lint <chart-dir>
helm template test <chart-dir>

If helm is unavailable, report the block clearly and perform partial checks:

• bash -n scripts/generate_chart_structure.sh
• bash -n scripts/generate_standard_helpers.sh
• Verify generated files and key fields manually

Re-run validation after any fixes.

Template Functions Quick Reference

See references/helm_template_functions.md for complete guide.

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 look up 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: Run helm-validator (or local lint/template fallback), then test with different values

Error Handling

Example Flows

Full scaffold with templates, ingress, HPA, and explicit port mapping:

bash scripts/generate_chart_structure.sh webapp ./charts \
  --image ghcr.io/acme/webapp:2.3.1 \
  --port 80 \
  --target-port 8080 \
  --type deployment \
  --with-templates \
  --with-ingress \
  --with-hpa

Digest-based image scaffold:

bash scripts/generate_chart_structure.sh api ./charts \
  --image ghcr.io/acme/api@sha256:0123456789abcdef \
  --with-templates

Minimal scaffold without templates:

bash scripts/generate_chart_structure.sh starter ./charts

Scaffold Success Criteria

Mark complete only when all checks pass:

• [ ] Chart.yaml, values.yaml, .helmignore, templates/NOTES.txt, and templates/_helpers.tpl exist
• [ ] values.yaml contains explicit service.port and service.targetPort
• [ ] If --with-templates was used, serviceaccount.yaml, service.yaml, configmap.yaml, secret.yaml, and one workload template exist
• [ ] Generated workload template uses conditional checksum annotations for config/secret
• [ ] Image rendering logic supports tag and digest modes
• [ ] Validation completed (helm-validator skill or local fallback commands) and outcomes reported

Resources

Scripts

References

Assets

Integration with helm-validator

After generating charts, invoke helm-validator and close the loop:

1. Generate chart/templates
2. Run helm-validator (or local fallback commands)
3. Fix identified issues
4. Re-validate until passing