# Rancher Catalog

A curated collection of Rancher 2.0 enhanced Helm charts. To see how catalogs are added and used in Rancher 2.0 take a look at the [docs page](https://rancher.com/docs/rancher/v2.x/en/concepts/catalogs/).

## Rancher Chart Structure

A Rancher chart repository differs slightly in directory structure from upstream repos in that it includes an `app version` directory. Though Rancher can use native Helm repositories as well.

A Rancher chart also has two additional files an `app-readme.md` file that provides a high level overview display in the Rancher 2.0 UI and a `questions.yml` file defining questions to prompt the user with. 

```
charts/wordpress/<app version>/
  app-readme.md            # Rancher Specific: Readme file for display in Rancher 2.0 UI
  charts/                  # Directory containing dependency charts
  Chart.yaml               # Required Helm chart information file
  questions.yml            # Rancher Specific: File containing questions for Rancher 2.0 UI
  README.md                # Optional: Helm Readme file (will be rendered in Rancher 2.0 UI as well)
  requirements.yaml        # Optional YAML file listing dependencies for the chart
  templates/               # A directory of templates that, when combined with values.yml will generate K8s YAML
  values.yaml              # The default configuration values for this chart
```
*See the upstream Helm chart [developer reference](https://helm.sh/docs/topics/chart_template_guide/) for a complete walk through of developing charts.*

To convert an upstream chart to take advantage of Rancher's enhanced UX, first create an `app-readme.md` file in the root of your chart.

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

# Wordpress ROCKS!
```

Then add a `questions.yml` file to prompt the user for something.

```
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
```

The above will prompt the user with a true / false radio button in the UI for enabling persistent storage. If the user choses to enable persistent storage they will be prompted for a storage class and volume size.

The above file also provides a list of categories that this chart fits into. This helps users navigate and filtering when browsing the catalog UI.

#### Question Variable Reference

| Variable  | Type | Required | Description |
| ------------- | ------------- | --- |------------- |
| 	variable          | string  | true    |  define the variable name specified in the `values.yaml`file, using `foo.bar` for nested object. |
| 	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 vriable type is `enum`, for example: options:<br> - "ClusterIP" <br> - "NodePort" <br> - "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"`|

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

## License
Copyright (c) 2018 [Rancher Labs, Inc.](http://rancher.com)

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

[http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0)

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
    
