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

helm-chart-patterns