Chart Documentation
Chart Documentation in Helm explains how to structure, manage, and deploy Kubernetes applications using Helm charts.
Chart Documentation provides comprehensive information about a Helm chart, detailing its purpose, configuration options, dependencies, and usage instructions. It serves as a reference for users and operators to understand how to deploy and manage applications or services packaged as Helm charts in Kubernetes environments. Proper Chart Documentation ensures clarity, ease of use, and maintainability of the chart by clearly explaining what the chart does, how to customize it, and how to troubleshoot it.
Overview
Purpose of the Chart
This section describes the application or service the chart installs, including its main functionalities, target audience, and use cases. It explains what the chart packages, the environment it is designed for, and any assumptions or prerequisites required for its operation.
Chart Structure
An explanation of the chart’s components such as templates, values files, and metadata. This includes a description of how the chart is organized to deploy Kubernetes resources like Deployments, Services, ConfigMaps, and Ingresses.
Configuration
Values and Parameters
This section documents all configurable parameters available in the values.yaml file. Each parameter is described with its purpose, data type, default value, and any valid options or constraints. This allows users to customize the chart behavior without modifying templates.
Example:
| Parameter | Description | Type | Default | Valid Values |
|---|---|---|---|---|
replicaCount | Number of pod replicas | int | 1 | Any positive integer |
image.repository | Container image repository | string | nginx | Valid Docker image strings |
service.type | Kubernetes service type | string | ClusterIP | ClusterIP, NodePort, LoadBalancer |
Environment Variables and Secrets
Details on environment variables that can be set via the chart and guidance on how to securely manage sensitive information like passwords or API keys, including references to Kubernetes Secrets integration.
Usage
Installation Instructions
Step-by-step commands required to install the chart using Helm, including examples with custom values.
helm repo add example-repo https://example.com/charts
helm install my-release example-repo/my-chart --values custom-values.yaml
Upgrading and Uninstalling
Instructions on how to upgrade the chart to newer versions and how to safely uninstall it, preserving or deleting related Kubernetes resources.
helm upgrade my-release example-repo/my-chart
helm uninstall my-release
Dependencies
Chart Dependencies
A list of other Helm charts or Kubernetes components that this chart depends on, including version constraints. Guidance on managing these dependencies, whether they are bundled or need to be installed separately.
External Services
Information about any required external services or infrastructure that must be accessible for the chart to function correctly, such as databases, message queues, or cloud services.
Templates and Customization
Template Overview
Explanation of key Helm templates included in the chart, how they generate Kubernetes manifests, and how they use values to configure resources dynamically.
Hooks and Lifecycle Events
Description of Helm hooks used in the chart to perform actions at specific lifecycle events such as pre-install, post-install, pre-upgrade, or post-delete.
Troubleshooting and Support
Common Issues
A list of known issues or common problems users may encounter when installing or operating the chart, along with recommended solutions or workarounds.
Logging and Debugging
Guidance on how to enable debug mode in Helm and how to inspect logs or events in Kubernetes to diagnose issues related to the chart deployment.
helm install my-release example-repo/my-chart --debug
kubectl logs -l app=my-release
Reporting Bugs and Getting Help
Information on how and where to report bugs, request features, or seek support, including links to issue trackers, forums, or chat channels.
Licensing and Credits
License Information
Details on the licensing terms governing the use and distribution of the chart and any included software components.
Contributors and Maintainers
Acknowledgement of individuals or teams responsible for maintaining and developing the chart, including contact information or links to project repositories.
Additional Resources
Related Documentation
Links or references to official documentation for the packaged application, Kubernetes concepts relevant to the chart, or Helm best practices.
Examples and Use Cases
Sample configurations and scenarios demonstrating advanced usage or integration patterns, helping users adapt the chart to their specific environments.