Helm Values Validator

Lightweight docker container that validates Helm charts using the kubeconform-helm plugin and the kubeconform schema validation tool. It ensures that your Kubernetes manifests generated from Helm charts conform to Kubernetes schema standards.

Features

• Helm Plugin Integration: Uses the kubeconform-helm plugin for Helm chart validation
• Custom Values Support: Validates charts with multiple values files, merged in the order specified
• Remote Chart Support: Validate charts directly from Helm repositories without manual downloads
• Verbose Reporting: Provides detailed output with --verbose and --summary flags
• Configurable: Supports .kubeconform files for custom validation settings

Prerequisites

• Docker installed on your system
• Values files ready for validation

Usage

1. Build the Docker Image

docker build -t helm-validator .

2. Run the Validator

The validator supports two modes of operation: local chart validation and remote chart validation. Values files are merged in the order they are mounted.

Validating a Local Chart Directory:

docker run --rm \
    -v /path/to/chart:/chart \
    -v /path/to/base.yaml:/values-0 \
    -v /path/to/env.yaml:/values-1 \
    -v /path/to/overrides.yaml:/values-2 \
    helm-validator --local /chart

Validating a Remote Chart:

docker run --rm \
    -v /path/to/base.yaml:/values-0 \
    -v /path/to/env.yaml:/values-1 \
    -v /path/to/overrides.yaml:/values-2 \
    helm-validator --remote <repo-name> <repo-url> <chart-name>

Values files are merged in the order specified by their mount points (/values-0, /values-1, etc.), with later files taking precedence.

Example Output

Adding Helm repository 'argo' from https://argoproj.github.io/argo-helm...
Updating Helm repositories...
Pulling chart 'argo/argo-workflows'...
Chart extracted to: /tmp/helm-charts/argo-workflows

Values files (in merge order):
  - 00-values.yaml (from /values-0)
  - 01-values.yaml (from /values-1)
  - 02-values.yaml (from /values-2)

Validating Helm chart...
Validation Output:
 stdin - ServiceAccount argo is valid
 stdin - ConfigMap argo-workflows-config is valid
 [...]
Summary: 22 resources found parsing stdin - Valid: 22, Invalid: 0, Errors: 0, Skipped: 0

Validation completed successfully!

Common Examples

Argo Workflows with environment overlays:

docker run --rm \
    -v ./base.yaml:/values-0 \
    -v ./prod.yaml:/values-1 \
    helm-validator --remote argo https://argoproj.github.io/argo-helm argo-workflows

Prometheus Stack with multiple configurations:

docker run --rm \
    -v ./defaults.yaml:/values-0 \
    -v ./storage.yaml:/values-1 \
    -v ./alerts.yaml:/values-2 \
    helm-validator --remote prometheus-community https://prometheus-community.github.io/helm-charts kube-prometheus-stack

Cert Manager with different issuers:

docker run --rm \
    -v ./base.yaml:/values-0 \
    -v ./cluster-issuers.yaml:/values-1 \
    helm-validator --remote jetstack https://charts.jetstack.io cert-manager

Additional Config

kubeconform File

You can include a .kubeconform file in your Helm chart directory to customize validation. Example:

schema-location:
  - default
  - https://my-schema-store/{{.Group}}/{{.ResourceKind}}_{{.ResourceAPIVersion}}.json
summary: true
verbose: true
strict: true

This file is automatically used by the tool during validation.

License

MIT License.