hello-world-app-new.yaml

# Step 1: Define and install WorkloadType and Trait
---
apiVersion: core.oam.dev/v1alpha1
kind: WorkloadType
metadata:
  name: cache.crossplane.io/v1.Radius # we endorse G/V/K convension as WorkloadType name
spec:
  schematic: |
    apiVersion: apiextensions.k8s.io/v1
    kind: CustomResourceDefinition
    metadata:
      name: radius.cache.crossplane.io
      scope: Namespaced
      names:
        plural: radius
        singular: radius
        kind: Radius
    spec:
      group: cache.crossplane.io
      versions:
        - name: v1
          schema:
            openAPIV3Schema:
            type: object
            properties:
               spec:
               type: object
               properties:
                 address:
                   type: string
                 maxMemory:
                   type: integer
                 thread:
                   type: integer
---
apiVersion: core.oam.dev/v1alpha1
Kind: Trait
metadata:
  name: autoscaling   
spec:
  appliesTo:
   - core.oam.dev/v1alpha1.Server
   - cache.crossplane.io/v1.Radius
  schematic: |
    apiVersions: apiextensions.k8s.io/v1
    kind: CustomResourceDefinition
    metadata:
      name: autoscaling.scaling.crossplane.io
    spec:
     group: crossplane.io
     scope: Namespaced
     names:
       plural: autoscalings
       singular: autoscaling
       kind: Autoscaling
     versions:
       - name: v1
         served: true
         storage: true
         schema:
           openAPIV3Schema:
           type: object
           properties:
             spec:
             type: object
             properties:
               interval:
                 type: integer
               maxCpuUsage:
                 type: integer
               minInstance:
                 type: integer
               maxInstance:
                 type: integer
---
apiVersion: core.oam.dev/v1alpha1
Kind: Trait
metadata:
  name: ingress
spec:
  appliesTo:
    - core.oam.dev/v1alpha1.Server
    - cache.crossplane.io/v1.Radius
  schematic: |
    // networking.crossplane.io/v1.Ingress
    // ...

# Step 2: Define Component and Application Configuration
---
apiVersion: core.oam.dev/v1alpha1
kind: ApplicationConfiguration
metadata:
  name: hello-world-app
  annotations:
    version: v0.0.1
    description: "very first OAM app for the new spec"
spec:
  components:
    - name: ryan-radius
      workloadSettings:
        apiVersion: cache.crossplane.io/v1
        kind: Radius
        metadata:
          name: ryan-radius
        spec:
          maxMemory: 256
          thread: 2
          address: "[fromParam(address, '127.0.0.1', string)]" # this is a function for parameter override. So we don't need `parameters` field
      parameterValues:
        - name: address
          value: 192.168.0.1
      traits:
        - name: scale-radius
          properties:
            apiVersion: scaling.crossplane.io/v1
            kind: Autoscaling
            metadata:
              name: scale-radius
            spec:
              interval: 1
              maxCpuUsage: 80
              minInstance: 2
              maxInstance: 10
        - name: nginx-ingress
          properties:
            apiVersion: networking.crossplane.io/v1
            kind: Ingress
            metadata:
              name: nginx-ingress
            spec:
              route: myapp.com
              tls: true

# (optional) Non-overlay version
---
apiVersion: core.oam.dev/v1alpha1 
kind: Component
metadata:
  name: ryan-radius
spec: 
  workloadSettings:
    apiVersion: cache.crossplane.io/v1
    kind: Radius
    metadata:
      name: ryan-radius
    spec:
      maxMemory: 256
      thread: 2
      address: "[fromParam(address, '127.0.0.1'), string]" # this is a function for parameter override. So we don't need `parameters` field

---
apiVersion: core.oam.dev/v1alpha1
kind: ApplicationConfiguration
metadata:
  name: hello-world-app
  annotations:
    version: v0.0.1
    description: "very first OAM app for the new spec"
spec:
  components:
    - name: ryan-radius
      componentRef: ryan-radius # the name of Component
      parameterValues:
        - name: address
          value: 192.168.0.1
      traits:
        ...

Compare with old proposal: https://gist.github.com/resouer/d2a0f9846df65ae478f472889e4839d7