Helm Chart Patterns

Expert guidance for developing production-grade Helm charts covering chart structure, templating patterns, multi-environment configuration, dependency management, testing strategies, and distribution workflows for Kubernetes application packaging.

When to Use This Skill Creating reusable Helm charts for applications and services Building application catalogs and chart repositories Managing multi-environment deployments (dev, staging, production) Implementing advanced templating with conditionals and loops Managing chart dependencies and subcharts Implementing chart hooks for lifecycle management Testing and validating chart templates Packaging and distributing charts via repositories Using Helmfile for multi-chart orchestration Core Concepts Chart Types Application charts: Standard deployable charts for your services Library charts: Reusable template helpers (not directly installable) Key Files File Purpose Chart.yaml Metadata, version, dependencies values.yaml Default configuration values.schema.json Input validation templates/_helpers.tpl Reusable template functions templates/*.yaml Kubernetes manifests Template Essentials Quote strings: {{ .Values.name | quote }} Indent properly: {{- toYaml . | nindent 4 }} Use helpers: {{ include "my-app.fullname" . }} Check nil: {{- if .Values.optional }} Quick Reference Task Load reference Chart structure & Chart.yaml skills/helm-chart-patterns/references/chart-structure.md Values file patterns skills/helm-chart-patterns/references/values-patterns.md Template patterns & functions skills/helm-chart-patterns/references/template-patterns.md Dependencies & subcharts skills/helm-chart-patterns/references/dependencies.md Hooks & lifecycle skills/helm-chart-patterns/references/hooks.md Testing patterns skills/helm-chart-patterns/references/testing.md Packaging & distribution skills/helm-chart-patterns/references/packaging.md Helmfile multi-chart skills/helm-chart-patterns/references/helmfile.md Best practices checklist skills/helm-chart-patterns/references/best-practices.md Workflow Structure - Set up chart directory with Chart.yaml and values.yaml Template - Create Kubernetes manifests with Go templating Helpers - Extract common patterns into _helpers.tpl Validate - Use values.schema.json for input validation Test - Lint, template, and run chart tests Package - Create .tgz and publish to repository Essential Commands

Development

helm create my-app # Scaffold new chart helm lint ./my-app # Validate chart helm template my-app ./my-app # Render templates

Dependencies

helm dependency update # Download dependencies helm dependency list # Show dependencies

Testing

helm install my-app ./my-app --dry-run --debug helm test my-app

Distribution

helm package ./my-app helm repo index . --url https://charts.example.com helm push my-app-1.0.0.tgz oci://registry.example.com/charts

Common Mistakes Forgetting to quote strings in templates Not using nindent for proper YAML formatting Committing secrets to values files Missing security contexts (runAsNonRoot, drop capabilities) Not pinning dependency versions Skipping values.schema.json validation Not testing upgrades from previous versions Resources Helm Documentation: https://helm.sh/docs/ Chart Template Guide: https://helm.sh/docs/chart_template_guide/ Best Practices: https://helm.sh/docs/chart_best_practices/ Helmfile: https://github.com/helmfile/helmfile Chart Testing: https://github.com/helm/chart-testing