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

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

pkg/cache/internal/informers_map.go

@@ -235,7 +235,7 @@ func createStructuredListWatch(gvk schema.GroupVersionKind, ip *specificInformer
 		return nil, err
 	}
 
-	client, err := apiutil.RESTClientForGVK(gvk, ip.config, ip.codecs)
+	client, err := apiutil.RESTClientForGVK(gvk, false, ip.config, ip.codecs)
 	if err != nil {
 		return nil, err
 	}

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) {
@@ -71,16 +80,16 @@ func GVKForObject(obj runtime.Object, scheme *runtime.Scheme) (schema.GroupVersi
 // RESTClientForGVK constructs a new rest.Interface capable of accessing the resource associated
 // with the given GroupVersionKind. The REST client will be configured to use the negotiated serializer from
 // baseConfig, if set, otherwise a default serializer will be set.
-func RESTClientForGVK(gvk schema.GroupVersionKind, baseConfig *rest.Config, codecs serializer.CodecFactory) (rest.Interface, error) {
-	cfg := createRestConfig(gvk, baseConfig)
+func RESTClientForGVK(gvk schema.GroupVersionKind, isUnstructured bool, baseConfig *rest.Config, codecs serializer.CodecFactory) (rest.Interface, error) {
+	cfg := createRestConfig(gvk, isUnstructured, baseConfig)
 	if cfg.NegotiatedSerializer == nil {
 		cfg.NegotiatedSerializer = serializer.WithoutConversionCodecFactory{CodecFactory: codecs}
 	}
 	return rest.RESTClientFor(cfg)
 }
 
 //createRestConfig copies the base config and updates needed fields for a new rest config
-func createRestConfig(gvk schema.GroupVersionKind, baseConfig *rest.Config) *rest.Config {
+func createRestConfig(gvk schema.GroupVersionKind, isUnstructured bool, baseConfig *rest.Config) *rest.Config {
 	gv := gvk.GroupVersion()
 
 	cfg := rest.CopyConfig(baseConfig)
@@ -93,5 +102,8 @@ func createRestConfig(gvk schema.GroupVersionKind, baseConfig *rest.Config) *res
 	if cfg.UserAgent == "" {
 		cfg.UserAgent = rest.DefaultKubernetesUserAgent()
 	}
+	if cfg.ContentType == "" && !isUnstructured && localScheme.Recognizes(gvk) {
+		cfg.ContentType = runtime.ContentTypeProtobuf
+	}
 	return cfg
 }

pkg/client/client_cache.go

@@ -22,6 +22,7 @@ import (
 
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/runtime/serializer"
@@ -50,13 +51,13 @@ type clientCache struct {
 
 // newResource maps obj to a Kubernetes Resource and constructs a client for that Resource.
 // If the object is a list, the resource represents the item's type instead.
-func (c *clientCache) newResource(gvk schema.GroupVersionKind, isList bool) (*resourceMeta, error) {
+func (c *clientCache) newResource(gvk schema.GroupVersionKind, isList, isUnstructured bool) (*resourceMeta, error) {
 	if strings.HasSuffix(gvk.Kind, "List") && isList {
 		// if this was a list, treat it as a request for the item's resource
 		gvk.Kind = gvk.Kind[:len(gvk.Kind)-4]
 	}
 
-	client, err := apiutil.RESTClientForGVK(gvk, c.config, c.codecs)
+	client, err := apiutil.RESTClientForGVK(gvk, isUnstructured, c.config, c.codecs)
 	if err != nil {
 		return nil, err
 	}
@@ -88,7 +89,10 @@ func (c *clientCache) getResource(obj runtime.Object) (*resourceMeta, error) {
 	// Initialize a new Client
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	r, err = c.newResource(gvk, meta.IsListType(obj))
+	_, isUnstructured := obj.(*unstructured.Unstructured)
+	_, isUnstructuredList := obj.(*unstructured.UnstructuredList)
+	isUnstructured = isUnstructured || isUnstructuredList
+	r, err = c.newResource(gvk, meta.IsListType(obj), isUnstructured)
 	if err != nil {
 		return nil, err
 	}