Use application/vnd.kubernetes.protobuf as content-type if possible

Signed-off-by: Siyu Wang <FillZpp.pub@gmail.com>

pkg/client/apiutil/apimachinery.go

@@ -27,10 +27,19 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/runtime/serializer"
 	"k8s.io/client-go/discovery"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/restmapper"
 )
 
+var (
+	localScheme = runtime.NewScheme()
+)
+
+func init() {
+	_ = clientgoscheme.AddToScheme(localScheme)
+}
+
 // NewDiscoveryRESTMapper constructs a new RESTMapper based on discovery
 // information fetched by a new client with the given config.
 func NewDiscoveryRESTMapper(c *rest.Config) (meta.RESTMapper, error) {
@@ -93,5 +102,8 @@ func createRestConfig(gvk schema.GroupVersionKind, baseConfig *rest.Config) *res
 	if cfg.UserAgent == "" {
 		cfg.UserAgent = rest.DefaultKubernetesUserAgent()
 	}
+	if cfg.ContentType == "" && localScheme.Recognizes(gvk) {
+		cfg.ContentType = runtime.ContentTypeProtobuf
+	}
 	return cfg
 }