Tutorial: Example Custom Chart Creation

In this tutorial, you’ll learn how to create a Helm chart and deploy it to a repository. The repository can then be used as a source for a custom catalog in Rancher.

You can fill your custom catalogs with either Helm Charts or Rancher Charts, although we recommend Rancher Charts due to their enhanced user experience.

For a complete walkthrough of developing charts, see the upstream Helm chart developer reference.

Within the GitHub repo that you’re using as your custom catalog, create a directory structure that mirrors the structure listed in Chart Directory Structure.

Rancher requires this directory structure, although app-readme.md and questions.yml are optional.
Tip:
- To begin customizing a chart, copy one from either the Rancher Library or the Helm Stable.
- For a complete walk through of developing charts, see the upstream Helm chart developer reference.
Recommended: Create an app-readme.md file.

Use this file to create custom text for your chart’s header in the Rancher UI. You can use this text to notify users that the chart is customized for your environment or provide special instruction on how to use it.

Example:
```
$ cat ./app-readme.md

# Wordpress ROCKS!
```

Recommended: Create a questions.yml file.

This file creates a form for users to specify deployment parameters when they deploy the custom chart. Without this file, users must specify the parameters manually using key value pairs, which isn’t user-friendly.

The example below creates a form that prompts users for persistent volume size and a storage class.

For a list of variables you can use when creating a questions.yml file, see Question Variable Reference.

    categories:
    - Blog
    - CMS
    questions:
    - variable: persistence.enabled
    default: "false"
    description: "Enable persistent volume for WordPress"
    type: boolean
    required: true
    label: WordPress Persistent Volume Enabled
    show_subquestion_if: true
    group: "WordPress Settings"
    subquestions:
    - variable: persistence.size
        default: "10Gi"
        description: "WordPress Persistent Volume Size"
        type: string
        label: WordPress Volume Size
    - variable: persistence.storageClass
        default: ""
        description: "If undefined or null, uses the default StorageClass. Default to null"
        type: storageclass
        label: Default StorageClass for WordPress

Check the customized chart into your GitHub repo.

Result: Your custom chart is added to the repo. Your Rancher Server will replicate the chart within a few minutes.

Illumina

Tutorial: Example Custom Chart Creation