add the clusterProfile property

Author: ryanzhang-oss

keps/sig-multicluster/4322-cluster-inventory/README.md

@@ -524,12 +524,150 @@ minimum kubelet version, maximum kubelet version, and enabled featureset version
 
 #### Properties
 
-Name/value pairs to represent properties of the clusters. It could be a
-collection of ClusterProperty resources, but could also be info based on
+Name/value pairs to represent properties of the clusters. One possible usage of properties is 
+to help another controller to make workload orchestration decisions. They could be 
+a set of [About-API](https://github.com/kubernetes/enhancements/tree/master/keps/sig-multicluster/2149-clusterid)
+ClusterProperty resources collected from the member clusters, but could also be info based on
 other implementations. The name of the cluster property can be predefined
 name from ClusterProperty resources and is allowed to be customized by
 different cluster managers.
 
+For all the about-api ClusterProperty that clusterProfile would honor, it MUST have a label with key “multicluster.x-k8s.io/clusterProfile” and value of “true”.
+
+Here are a few ClusterProperty that the clusterProfile API would also support. 
+
+##### cluster-endpoints.k8s.io
+All clusterProfile API MUST have this property. It is a list of the url that can reach the api-server of the k8s cluster
+  * It could contain IP addresses too
+  
+Here is an example of a cluster-endpoints.k8s.io ClusterProperty
+```yaml
+apiVersion: about.k8s.io/v1
+kind: ClusterProperty
+metadata:
+  name: cluster-endpoints.k8s.io
+  labels:
+    multicluster.x-k8s.io/clusterProfile: “true”
+spec:
+  value: ["100.3.3.4:5683","qs-oar7gr9p.azmk8s.io:443"]
+```
+Here is the corresponding ClusterProfile API
+```yaml
+properties:
+   - name: cluster-endpoints.k8s.io
+     value:  ["100.3.3.4:5683","qs-oar7gr9p.azmk8s.io:443"]
+```
+
+##### location.topology.k8s.io
+It contains the location of the k8s cluster
+* It could be a country, region, zone, or any other location information
+* It is immutable
+
+Here is an example of a location.topology.k8s.io ClusterProperty
+```yaml
+apiVersion: about.k8s.io/v1
+kind: ClusterProperty
+metadata:
+  name: location.topology.k8s.io
+  labels:
+    multicluster.x-k8s.io/clusterProfile: “true”
+Spec:
+  value: cloud.google/us-east1
+```
+Here is the corresponding ClusterProfile API
+```yaml
+properties:
+   - name: location.topology.k8s.io
+     value: cloud.google/us-east1
+```
+
+##### count.node.k8s.io
+It contains the total number of nodes in the k8s clusters
+* The value is dynamic but not changing fast.
+
+Here is an example of a count.node.k8s.io ClusterProperty
+```yaml
+apiVersion: about.k8s.io/v1
+kind: ClusterProperty
+metadata:
+  name: count.node.k8s.io
+  labels:
+    multicluster.x-k8s.io/clusterProfile: “true”
+Spec:
+  value: 120
+```
+Here is the corresponding ClusterProfile API
+```yaml
+properties:
+   - name: count.node.k8s.io
+     value: 120
+```
+
+##### type.node.k8s.io
+It contains the list of type of node in the k8s clusters
+* The list is dynamic but does not change much unless there is a node auto provisioner.
+
+Here is an example of a type.node.k8s.io ClusterProperty
+```yaml
+apiVersion: about.k8s.io/v1
+kind: ClusterProperty
+metadata:
+  name: type.node.k8s.io
+  labels:
+    multicluster.x-k8s.io/clusterProfile: “true”
+Spec:
+  value: ["g6.xlarge","Standard_NC48ads_H100","m3-ultramem-32","largeCPU","smallMem"]
+```
+Here is the corresponding ClusterProfile API
+```yaml
+properties:
+   - name: type.node.k8s.io
+     value: ["g6.xlarge","Standard_NC48ads_H100","m3-ultramem-32","largeCPU","smallMem"]
+```
+##### metrics-endpoints.k8s.io
+It contains an array of the type, url pair that one can query the metrics (for example, a Prometheus or Grafana endpoint for PromQL) of the cluster
+* It could contain IP addresses too
+* The list is dynamic but should not change much.
+
+Here is an example of a metrics-endpoints.k8s.io ClusterProperty
+```yaml
+apiVersion: about.k8s.io/v1
+kind: ClusterProperty
+metadata:
+  name: metrics-endpoints.k8s.io
+  labels:
+    multicluster.x-k8s.io/clusterProfile: “true”
+Spec:
+  value: [{"Prometheus":"100.3.3.4:9990"}, {"Grafana":"example.grafana.io:9990"}]
+```
+Here is the corresponding ClusterProfile API
+```yaml
+properties:
+   - name: metrics-endpoints.k8s.io
+     value: [{"Prometheus":"100.3.3.4:9990"}, {"Grafana":"example.grafana.io:9990"}]
+```
+
+##### group.customResource.k8s.io
+It contains an array of custom resources definitions (CRDs) group that this cluster supports.
+* The list is dynamic but should not change much.
+
+Here is an example of a group.customResource.k8s.io ClusterProperty
+```yaml
+apiVersion: about.k8s.io/v1
+kind: ClusterProperty
+metadata:
+  name: group.customResource.k8s.io
+  labels:
+    multicluster.x-k8s.io/clusterProfile: “true”
+Spec:
+  value: ["argoproj.io","kubeflow.org","istio.io","volcano.sh"]
+```
+Here is the corresponding ClusterProfile API
+```yaml
+properties:
+   - name: group.customResource.k8s.io
+     value: ["argoproj.io","kubeflow.org","istio.io","volcano.sh"]
+```
 #### Conditions
 
 Record cluster’s healthiness condition and easy to extend, conforming to