Helm Chart Builder

Category: Engineering Domain: Kubernetes & Helm

Overview

The Helm Chart Builder skill provides automated analysis of Helm charts including structure validation, values checking, template inspection, and dependency review. It helps teams maintain high-quality charts with correct configurations, proper security contexts, and complete documentation.

Quick Start

# Analyze chart structure and quality
python scripts/chart_analyzer.py --path ./charts/my-app

# Validate values.yaml against chart requirements
python scripts/values_validator.py --chart ./charts/my-app --values values-prod.yaml

# JSON output for CI
python scripts/chart_analyzer.py --path ./charts/my-app --format json

# Validate multiple values files
python scripts/values_validator.py --chart ./charts/my-app --values values-dev.yaml values-prod.yaml

Tools Overview

chart_analyzer.py

Analyzes Helm chart structure, metadata, templates, and dependencies.

Feature	Description
Structure validation	Checks required files exist (Chart.yaml, values.yaml, templates/)
Metadata check	Validates Chart.yaml fields, version format, appVersion
Template review	Inspects templates for common patterns and issues
Dependency analysis	Reviews subchart dependencies and version constraints
Documentation check	Verifies NOTES.txt and README presence

values_validator.py

Validates values files against chart expectations and Kubernetes best practices.

Feature	Description
Resource limits	Checks for CPU/memory requests and limits
Security context	Validates runAsNonRoot, readOnlyRootFilesystem
Replica count	Checks for production-appropriate replica counts
Image tags	Flags use of latest or missing image tags
Ingress config	Validates ingress annotations and TLS settings

Workflows

Chart Review Workflow

1. Analyze structure - Run chart_analyzer.py to check chart organization
2. Validate defaults - Run values_validator.py against default values.yaml
3. Check environments - Validate each environment's values file
4. Review findings - Address critical issues first, then warnings
5. Re-check - Confirm fixes pass validation

Pre-Release Workflow

1. Bump version - Update Chart.yaml version and appVersion
2. Lint chart - Run chart_analyzer.py in strict mode
3. Validate all values - Check every environment's values file
4. Check dependencies - Ensure subchart versions are pinned
5. Package - Chart is ready for helm package

CI Integration

# Structure check
python scripts/chart_analyzer.py --path ./charts/my-app --format json --strict

# Values validation for all environments
for env in dev staging production; do
  python scripts/values_validator.py \
    --chart ./charts/my-app \
    --values "values-${env}.yaml"
done

Reference Documentation

• Helm Best Practices - Chart structure, templates, security, dependencies

Common Patterns Quick Reference

Required Chart Structure

my-chart/
  Chart.yaml          # Required: chart metadata
  values.yaml         # Required: default values
  templates/          # Required: template directory
    deployment.yaml
    service.yaml
    _helpers.tpl      # Recommended: template helpers
    NOTES.txt         # Recommended: post-install notes
  charts/             # Optional: subchart dependencies

Values Best Practices

Setting	Requirement	Why
resources.limits	Required	Prevents resource exhaustion
resources.requests	Required	Enables proper scheduling
securityContext.runAsNonRoot	Required	Security baseline
image.tag	Required (not latest)	Reproducible deployments
replicaCount >= 2	Recommended for prod	High availability
ingress.tls	Recommended	Encrypted traffic

Chart.yaml Required Fields

Field	Description
apiVersion	v2 for Helm 3
name	Chart name (lowercase)
version	SemVer chart version
appVersion	Application version
description	Brief chart description

Common Issues

Issue	Severity	Fix
Missing Chart.yaml	Critical	Add required chart metadata
No resource limits	Warning	Set CPU/memory limits
Latest image tag	Warning	Pin specific version
No security context	Warning	Add runAsNonRoot: true
Missing NOTES.txt	Info	Add post-install notes
Unpinned dependencies	Warning	Pin subchart versions