helm-chart-builder

Imported from borghei/claude-skills (engineering/helm-chart-builder/SKILL.md). Install upstream with npx skills add borghei/claude-skills --skill helm-chart-builder. Copyright stays with the author (MIT + Commons Clause).

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.

Clarify First

Before analyzing the chart, settle the inputs below. When one is missing or vague and would change the result, ask about it; when it wouldn't, use a sensible default and say which one you used.

• Chart path: which chart directory to analyze (sets --path/--chart).
• Values files: which environment values files to validate (sets --values and what gets checked against best practices).
• Strictness: strict/lint mode and JSON for CI (sets --strict --format json and whether findings gate the pipeline).

Ask about the two or three inputs that matter most for this request, not the whole list. If the user wants a result straight away, produce it and state your assumptions at the top.

Quick Start

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

# Validate a values file against best-practice rules (--chart only helps locate the file)
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.

values_validator.py

Validates values files against fixed Kubernetes best-practice rules. --chart is only used to find a values file given as a path relative to the chart directory; values are not compared with what the chart's templates use.

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

Scope & Limitations

In Scope:

• Static review of a Helm chart directory with chart_analyzer.py: required files, Chart.yaml fields and version format, template file checks, subchart dependency pinning, and NOTES.txt and README presence.
• Best-practice checks on one or more values files with values_validator.py: resource requests and limits, security context, image tags, replica count, service, ingress TLS, probes and autoscaling.
• Text or JSON output, with --strict on the analyzer to treat warnings as errors in CI.
• The chart review and pre-release workflows, backed by references/helm-best-practices.md.

Out of Scope:

• Rendering, linting, installing or upgrading charts. The scripts do not call helm or a cluster.
• Generating new charts or templates. The scripts review existing files.
• Kubernetes operators and custom controllers (see engineering/kubernetes-operator/).
• Building container images (see engineering/docker-development/) and designing CI pipelines (see engineering/ci-cd-pipeline-builder/).

Important Caveats:

• Both scripts read YAML with a small stdlib parser and inspect templates with regular expressions. Template logic, --set overrides and values merged at install time are not evaluated, so a clean report does not mean the rendered manifests are correct.
• values_validator.py checks each values file against fixed best-practice rules. The --chart flag only locates the files; values are not compared with what the chart's templates actually use.
• Findings are review prompts, not proof that a chart is secure or production ready. The reference lists helm lint, helm template and a dry-run install as the checks that cover rendering.

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

Chart.yaml Required Fields

Common Issues