binura-g

#@ load("@ytt:data", "data")
#@ load("@ytt:struct", "struct")
#@ load("@ytt:assert", "assert")

#@ app = data.values.app

## Note how all the logic is written in yaml comments - hence why it's been excluded from the shortlist.

---
apiVersion: apps/v1

binura-g

#@data/values-schema
app:
  name: ""
  image: "nginx:1.27"
  replicas: 1
  ingressClass: "nginx"
  serviceType: "ClusterIP"
  gatewayName: "default-gateway"
  endpoints:
    - name: ""

binura-g

apiVersion: platform.example.org/v1alpha1
kind: WebApp
metadata:
  name: react-app
spec:
  image: ghcr.io/acme/react-app:main
  replicas: 2
  endpoints:
    - name: react-ui
      host: app.foo.com

binura-g

apiVersion: apiextensions.crossplane.io/v1
kind: Composition
metadata:
  name: webapp
spec:
  compositeTypeRef:
    apiVersion: platform.example.org/v1alpha1
    kind: WebApp
  resources:
    - name: deployment

binura-g

apiVersion: apiextensions.crossplane.io/v1
kind: CompositeResourceDefinition
metadata:
  name: webapps.platform.example.org
spec:
  group: platform.example.org
  names:
    kind: WebApp
    plural: webapps
  claimNames:

binura-g

apiVersion: kro.run/v1alpha1
kind: ResourceGraphDefinition
metadata:
  name: webapps.kro.run
spec:
  schema:
    apiVersion: v1alpha1
    kind: WebApp
    spec:
      name: string

binura-g

Comparing schema validations between jsonnet and CUE.

Jsonnet requires validation functions to be written - with CUE it's built it and the result is much less verbose.

Jsonnet validation example (can be inlined with the schema, but gets verbose. Best split into a different file).

local std = std;

{

binura-g

local web = import 'webApp.libsonnet';

web.webApp({
  name: 'react',
  image: 'ghcr.io/acme/react-app:main',
  replicas: 2,
  gatewayName: 'default-gateway',
  ingressClass: 'nginx',
  serviceType: 'ClusterIP',
  endpoints: [

binura-g

local std = std;

{
  webApp(v):
    local name         = v.name;
    local image        = v.image;
    local replicas     = std.get(v, 'replicas', 1);
    local ingressClass = std.get(v, 'ingressClass', 'nginx');
    local serviceType  = std.get(v, 'serviceType', 'ClusterIP');
    local gatewayName  = std.get(v, 'gatewayName', 'default-gateway');

binura-g

package webapp

# This can be a 'normal' YAML as well. CUE can import raw YAMLs directly.

app: {
	name:  "react"
	image: "ghcr.io/acme/react-app:main"
	replicas: 2

	ingressClass: "nginx"