nixmomo/charts

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.

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 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.yamlfile, 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, multiline, boolean, int, enum, password, storageclass, hostname, pvc, and secret).
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: - "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"

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.

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

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.