Customizing Charts
- What’s Next?
- Question Variable Reference

Customizing Charts

Before you can deploy customized catalog apps using Rancher, you must add charts to the GitHub repository serving as your custom catalog.

The custom catalog can contain native Helm charts, Rancher charts, or a combination of both (although we recommend using Rancher charts).

先决条件:
Recommended: Read Catalogs and Charts.
Create a GitHub repository to serve as your custom catalog.
Complete Adding Custom Catalogs.
Note: Customization of Helm charts takes place outside of the Rancher UI.

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.

What’s Next?

Launch your custom catalog app. For more information, see Launching a Catalog App.

Question Variable Reference

This reference contains variables that you can use in questions.yml.

Variable	Type	Required	Description
variable	string	true	Define the variable name specified in the `values.yml` file, using `foo.bar` for nested objects.
label	string	true	Define the UI label.
description	string	false	Specify the description of the variable.
type	string	false	Default to `string` if not specified (current supported types are string, boolean, int, enum, password, storageclass and hostname).
required	bool	false	Define if the variable is required or not (true \| false)
default	string	false	Specify the default value.
group	string	false	Group questions by input value.
min_length	int	false	Min character length.
max_length	int	false	Max character length.
min	int	false	Min integer length.
max	int	false	Max integer length.
options	[]string	false	Specify the options when the variable type is `enum`, for example: options: - “ClusterIP” - “NodePort” - “LoadBalancer”
valid_chars	string	false	Regular expression for input chars validation.
invalid_chars	string	false	Regular expression for invalid input chars validation.
subquestions	[]subquestion	false	Add an array of subquestions.
show_if	string	false	Show current variable if conditional variable is true. For example `show_if: "serviceType=Nodeport"`
show_subquestion_if	string	false	Show subquestions if is true or equal to one of the options. for example `show_subquestion_if: "true"`

Note: subquestions[] cannot contain subquestions or show_subquestions_if keys, but all other keys in the above table are supported.