Initial UnstructuredExtract without caching

Kubernetes-commit: 6e481c5db19cda1ef1b7506c22c0046e440c7fe2

applyconfigurations/meta/v1/unstructured.go

@@ -0,0 +1,79 @@
+package v1
+
+import (
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/managedfields"
+	"k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager"
+	"k8s.io/client-go/discovery"
+	"k8s.io/kube-openapi/pkg/util/proto"
+	"sigs.k8s.io/structured-merge-diff/v4/typed"
+)
+
+type UnstructuredExtractor interface {
+	ExtractUnstructured(object *unstructured.Unstructured, fieldManager string) (*unstructured.Unstructured, error)
+	ExtractUnstructuredStatus(object *unstructured.Unstructured, fieldManager string) (*unstructured.Unstructured, error)
+}
+
+type parserCache interface {
+	parserForGVK(gvk schema.GroupVersionKind) (*typed.ParseableType, error)
+}
+
+type nonCachingParserCache struct {
+	discoveryClient *discovery.DiscoveryClient
+}
+
+func (c *nonCachingParserCache) parserForGVK(gvk schema.GroupVersionKind) (*typed.ParseableType, error) {
+	doc, err := c.discoveryClient.OpenAPISchema()
+	if err != nil {
+		return nil, err
+	}
+
+	models, err := proto.NewOpenAPIData(doc)
+	if err != nil {
+		return nil, err
+	}
+
+	gvkParser, err := fieldmanager.NewGVKParser(models, false)
+	if err != nil {
+		return nil, err
+	}
+
+	return gvkParser.Type(gvk), nil
+}
+
+type extractor struct {
+	cache parserCache
+}
+
+func NewUnstructuredExtractor(dc *discovery.DiscoveryClient) UnstructuredExtractor {
+	return &extractor{
+		cache: &nonCachingParserCache{dc},
+	}
+}
+
+func (e *extractor) ExtractUnstructured(object *unstructured.Unstructured, fieldManager string) (*unstructured.Unstructured, error) {
+	return e.extractUnstructured(object, fieldManager, "")
+}
+
+func (e *extractor) ExtractUnstructuredStatus(object *unstructured.Unstructured, fieldManager string) (*unstructured.Unstructured, error) {
+	return e.extractUnstructured(object, fieldManager, "status")
+}
+
+func (e *extractor) extractUnstructured(object *unstructured.Unstructured, fieldManager string, subresource string) (*unstructured.Unstructured, error) {
+	gvk := object.GetObjectKind().GroupVersionKind()
+	parser, err := e.cache.parserForGVK(gvk)
+	if err != nil {
+		return nil, err
+	}
+	result := &unstructured.Unstructured{}
+	err = managedfields.ExtractInto(object, *parser, fieldManager, result, subresource)
+	if err != nil {
+		return nil, err
+	}
+	result.SetName(object.GetName())
+	result.SetNamespace(object.GetNamespace())
+	result.SetKind(object.GetKind())
+	result.SetAPIVersion(object.GetAPIVersion())
+	return result, nil
+}