kusion init provides a new way to collect template params value with specified CLI flag

[howieyuen]

Enhancement

Summary

kusion init is a helpful tool to create a new project of KCL. Consider that we have two different roles, one is template developer, who is responsible for design and develop template, as well as a set of default values; another is to use template. For quick start of template rendering, developer provides a YAML file, named kusion.yaml, which contains type and default value of all params that is used by go template engine.

However, if I want to override template default value, there is only one solution: type new default when each Prompt asks, which is strongly Inefficient.

Proposal

Add a new flag(CustomParams) to override template defaults. Kusion must to provide a struct with filed name and type. User can prepare a new set of defaults in advance, based on file kusion.yaml.

Design Details

Field Types

Although we encourage all to use primitive type for template params:

• string
• int
• float
• bool

But we must admit there is always an exception, aka complicated data type, For example:

• array
• map
• struct
• any

and mixed complicated with primitives. So we need to explain every field type in kusion.yaml.

Flag Definition in Struct

kusion.yaml provide a struct as below:

kusion.yaml

projectName: my-app
description: A minimal kusion project of single stack
quickstart: kusion compile main.k -Y ci-test/settings.yaml
common:
  # base/base.k
  - name: ServiceName
    description: service name
    type: string
    default: frontend-svc
  - name: NodePort
    description: node port
    type: int
    default: 30000
  # project.yaml
  - name: ProjectName
    description: project name
    type: string
    default: my-app
stacks:
  - name: dev
    fields:
      # stack/ci-test/settings.yaml
      - name: Stack
        description: stack env. One of dev,test,stable,pre,sim,gray,prod.
        type: string
        default: dev
      # stack/main.k
      - name: Image
        description: The Image Address. Default to 'gcr.io/google-samples/gb-frontend:v4'
        type: string
        default: gcr.io/google-samples/gb-frontend:v4
      # stack/stack.yaml
      - name: ClusterName
        description: The Cluster Name. Default to 'kubernetes-dev'
        type: string
        default: kubernetes-dev

Implicit struct of CustomParams flag:

struct definition

{
	"projectConfig": {
		"ServiceName": "frontend-svc",
		"NodePort": 30000,
		"ProjectName": "my-app"
	},
	"stacksConfig": {
		"dev": {
			"Stack": "dev",
			"Image": "gcr.io/google-samples/gb-frontend:v4",
			"ClusterName": "kubernetes-dev"
		}
	}
}

[elliotxx]

Can you provide more example of custom parameter for CLI and 3rd-party system integration?

[howieyuen]

Can you provide more example of custom parameter for CLI and 3rd-party system integration?

CLI Example

Integration
please refer kusion doc here:
https://pkg.go.dev/kusionstack.io/kusion@v0.4.1/pkg/scaffold#CopyTemplateFiles
and here:
https://pkg.go.dev/kusionstack.io/kusion@v0.4.1/pkg/scaffold#LoadTemplate

Step1: call func LoadTemplate to parse kusion.yaml, and get default value of configs

alternative: use custom params

Step2: use default values as input params for func CopyTemplateFiles

[howieyuen]

Can you provide more example of custom parameter for CLI and 3rd-party system integration?

CLI Example

Integration please refer kusion doc here: https://pkg.go.dev/kusionstack.io/kusion@v0.4.1/pkg/scaffold#CopyTemplateFiles and here: https://pkg.go.dev/kusionstack.io/kusion@v0.4.1/pkg/scaffold#LoadTemplate

Step1: call func LoadTemplate to parse kusion.yaml, and get default value of configs

alternative: use custom params

Step2: use default values as input params for func CopyTemplateFiles

CopyTemplateFiles use local file system as default, which needs to optimize params to be feasible to integrate with http service.