wrale-charts

Chart Guidelines

Chart Structure

A chart MUST have the following structure:

chart-name/
  ├── .helmignore        # Patterns to ignore when packaging
  ├── Chart.yaml         # Chart metadata
  ├── values.yaml        # Default configuration values
  ├── values.schema.json # JSON Schema for validating values.yaml
  ├── templates/         # Template files
  │   ├── NOTES.txt     # Post-installation notes
  │   ├── _helpers.tpl  # Common template helpers
  │   └── tests/        # Test files
  └── README.md         # Chart documentation

Chart.yaml Requirements

• name: Must be lowercase and hyphen-separated
• version: Must follow SemVer 2
• description: Must be clear and concise
• type: Must be either application or library
• home: URL of the project homepage
• sources: List of URLs to source code
• maintainers: List with name and email

Values Guidelines

1. Structure:
   • Use camelCase for keys
   • Group related values logically
   • Document all values in values.yaml
2. Defaults:
   • Must be production-ready
   • Must be secure by default
   • Should work out-of-the-box
3. Schema:
   • Provide JSON Schema in values.schema.json
   • Define types for all values
   • Add descriptions and examples

Template Best Practices

1. Metadata:

   metadata:
     name: 
     labels:
   

2. Helper Functions:
   • Use _helpers.tpl for common functions
   • Document each helper function
   • Test helper functions
3. Resources:
   • Use resource requests and limits
   • Make resources configurable
   • Set reasonable defaults
4. Security:
   • Enable security contexts
   • Use non-root users
   • Set read-only root filesystem
5. Configuration:
   • Use ConfigMaps for configuration
   • Use Secrets for sensitive data
   • Support external secrets

Testing Requirements

1. Template Tests:

   templates/tests/test-connection.yaml:
   apiVersion: v1
   kind: Pod
   metadata:
     name: "-test"
     annotations:
       "helm.sh/hook": test
   

2. CI Tests:
   • Must pass helm lint
   • Must pass helm test
   • Must pass template validation

Documentation Requirements

1. README.md:
   • Description of the chart
   • Prerequisites
   • Installation instructions
   • Configuration options
   • Examples
2. NOTES.txt:
   • Post-installation instructions
   • Access information
   • Next steps

Versioning Guidelines

1. Chart Version:
   • MAJOR: Incompatible API changes
   • MINOR: Functionality in backward compatible manner
   • PATCH: Bug fixes
2. App Version:
   • Track the version of the contained application
   • Document version compatibility

Contributing Guidelines

1. Pull Requests:
   • Update documentation
   • Add/update tests
   • Update CHANGELOG.md
2. Review Process:
   • Code review required
   • Test results required
   • Documentation review required

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