Add support for EndpointSlice in KubernetesClient

[rohanKanojia]

Right now we don't have DSL support for EndpointSlice in KubernetesClient. We should add something like this:

try (KubernetesClient client = new DefaultKubernetesClient()) {
  EndpointSlice endpointSlice = new EndpointSliceBuilder()
                                  // ..
                                  .build();
   
  client.discovery().v1beta1().endpointSlices().inNamespace("ns1").createOrReplace(endpointSlice);
}

When I try to create it using generic resource API, like this:

try (KubernetesClient client = new DefaultKubernetesClient()) {
    EndpointSlice endpointSlice = new EndpointSliceBuilder()
            .withNewMetadata()
            .withName("example-abc")
            .addToLabels("kubernetes.io/service-name", "example")
            .endMetadata()
            .withAddressType("IPv4")
            .addNewPort()
            .withName("http")
            .withPort(80)
            .endPort()
            .addNewEndpoint()
            .withAddresses("10.1.2.3")
            .withNewConditions().withReady(true).endConditions()
            .withHostname("pod-1")
            .addToTopology("kubernetes.io/hostname", "node-1")
            .addToTopology("topology.kubernetes.io/zone", "us-west2-a")
            .endEndpoint()
            .build();

    client.resource(endpointSlice).inNamespace("default").createOrReplace();
}

I get this error:

[main] WARN io.fabric8.kubernetes.client.internal.VersionUsageUtils - The client is using resource type 'endpointslices' with unstable version 'v1beta1'
Exception in thread "main" io.fabric8.kubernetes.client.KubernetesClientException: Failure executing: POST at: https://192.168.39.3:8443/apis/discovery/v1beta1/namespaces/default/endpointslices. Message: 404 page not found
.
	at io.fabric8.kubernetes.client.dsl.base.OperationSupport.requestFailure(OperationSupport.java:570)

Looks like this should be modified to discovery.k8s.io:

-    {"k8s.io/api/discovery/v1beta1", "", "io.fabric8.kubernetes.api.model.discovery", "kubernetes_discovery_", true},
+    {"k8s.io/api/discovery/v1beta1", "discovery.k8s.io", "io.fabric8.kubernetes.api.model.discovery", "kubernetes_discovery_", true},

kubernetes-client/kubernetes-model-generator/kubernetes-model-discovery/cmd/generate/generate.go

Line 72 in 6a7a7e4

{"k8s.io/api/discovery/v1beta1", "", "io.fabric8.kubernetes.api.model.discovery", "kubernetes_discovery_", true},