K8s: Add discovery client (#100995)

pkg/services/apiserver/client/discovery.go

@@ -0,0 +1,65 @@
+package client
+
+import (
+	"fmt"
+
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/discovery"
+	"k8s.io/client-go/rest"
+)
+
+type DiscoveryClient interface {
+	discovery.DiscoveryInterface
+	GetResourceForKind(gvk schema.GroupVersionKind) (schema.GroupVersionResource, error)
+	GetKindForResource(gvr schema.GroupVersionResource) (schema.GroupVersionKind, error)
+}
+
+type DiscoveryClientImpl struct {
+	restConfig *rest.Config
+	discovery.DiscoveryInterface
+}
+
+func NewDiscoveryClient(restConfig *rest.Config) (*DiscoveryClientImpl, error) {
+	discoveryClient, err := discovery.NewDiscoveryClientForConfig(restConfig)
+	if err != nil {
+		return nil, err
+	}
+	return &DiscoveryClientImpl{
+		restConfig:         restConfig,
+		DiscoveryInterface: discoveryClient,
+	}, nil
+}
+
+func (d *DiscoveryClientImpl) GetResourceForKind(gvk schema.GroupVersionKind) (schema.GroupVersionResource, error) {
+	resourceList, err := d.ServerResourcesForGroupVersion(gvk.GroupVersion().String())
+	if err != nil {
+		return schema.GroupVersionResource{}, err
+	}
+	for _, resource := range resourceList.APIResources {
+		if resource.Kind == gvk.Kind {
+			return schema.GroupVersionResource{
+				Group:    gvk.Group,
+				Version:  gvk.Version,
+				Resource: resource.Name,
+			}, nil
+		}
+	}
+	return schema.GroupVersionResource{}, fmt.Errorf("resource not found for %s", gvk.String())
+}
+
+func (d *DiscoveryClientImpl) GetKindForResource(gvr schema.GroupVersionResource) (schema.GroupVersionKind, error) {
+	resourceList, err := d.ServerResourcesForGroupVersion(gvr.GroupVersion().String())
+	if err != nil {
+		return schema.GroupVersionKind{}, err
+	}
+	for _, resource := range resourceList.APIResources {
+		if resource.Name == gvr.Resource {
+			return schema.GroupVersionKind{
+				Group:   gvr.Group,
+				Version: gvr.Version,
+				Kind:    resource.Kind,
+			}, nil
+		}
+	}
+	return schema.GroupVersionKind{}, fmt.Errorf("kind not found for %s", gvr.String())
+}