Don't register the kubeletconfig group with the default Scheme

cmd/kubelet/app/options/BUILD

@@ -12,11 +12,10 @@ go_library(
         "options.go",
     ],
     deps = [
-        "//pkg/api:go_default_library",
         "//pkg/apis/componentconfig:go_default_library",
         "//pkg/features:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
-        "//pkg/kubelet/apis/kubeletconfig/install:go_default_library",
+        "//pkg/kubelet/apis/kubeletconfig/scheme:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig/v1alpha1:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig/validation:go_default_library",
         "//pkg/util/taints:go_default_library",

cmd/kubelet/app/options/options.go

@@ -25,14 +25,12 @@ import (
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/apiserver/pkg/util/flag"
 	utilflag "k8s.io/apiserver/pkg/util/flag"
-	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/apis/componentconfig"
 	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
-	kubeletconfigvalidation "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/validation"
-	// Need to make sure the kubeletconfig api is installed so defaulting funcs work
-	_ "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/install"
+	kubeletscheme "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/scheme"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/v1alpha1"
+	kubeletconfigvalidation "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/validation"
 	utiltaints "k8s.io/kubernetes/pkg/util/taints"
 
 	"github.com/spf13/pflag"
@@ -142,10 +140,14 @@ func ValidateKubeletFlags(f *KubeletFlags) error {
 
 // NewKubeletConfiguration will create a new KubeletConfiguration with default values
 func NewKubeletConfiguration() (*kubeletconfig.KubeletConfiguration, error) {
+	scheme, _, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		return nil, err
+	}
 	versioned := &v1alpha1.KubeletConfiguration{}
-	api.Scheme.Default(versioned)
+	scheme.Default(versioned)
 	config := &kubeletconfig.KubeletConfiguration{}
-	if err := api.Scheme.Convert(versioned, config, nil); err != nil {
+	if err := scheme.Convert(versioned, config, nil); err != nil {
 		return nil, err
 	}
 	return config, nil

cmd/kubelet/app/server.go

@@ -756,7 +756,8 @@ func parseResourceList(m kubeletconfiginternal.ConfigurationMap) (v1.ResourceLis
 }
 
 // BootstrapKubeletConfigController constructs and bootstrap a configuration controller
-func BootstrapKubeletConfigController(flags *options.KubeletFlags,
+func BootstrapKubeletConfigController(
+	flags *options.KubeletFlags,
 	defaultConfig *kubeletconfiginternal.KubeletConfiguration) (*kubeletconfiginternal.KubeletConfiguration, *kubeletconfig.Controller, error) {
 	var err error
 	// Alpha Dynamic Configuration Implementation; this section only loads config from disk, it does not contact the API server
@@ -777,7 +778,10 @@ func BootstrapKubeletConfigController(flags *options.KubeletFlags,
 	}
 
 	// get the latest KubeletConfiguration checkpoint from disk, or load the init or default config if no valid checkpoints exist
-	kubeletConfigController := kubeletconfig.NewController(initConfigDir, dynamicConfigDir, defaultConfig)
+	kubeletConfigController, err := kubeletconfig.NewController(initConfigDir, dynamicConfigDir, defaultConfig)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to construct controller, error: %v", err)
+	}
 	kubeletConfig, err := kubeletConfigController.Bootstrap()
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to determine a valid configuration, error: %v", err)

cmd/kubelet/kubelet.go

@@ -89,7 +89,10 @@ func main() {
 	}
 
 	// construct a KubeletServer from kubeletFlags and kubeletConfig
-	kubeletServer := &options.KubeletServer{KubeletFlags: *kubeletFlags, KubeletConfiguration: *kubeletConfig}
+	kubeletServer := &options.KubeletServer{
+		KubeletFlags:         *kubeletFlags,
+		KubeletConfiguration: *kubeletConfig,
+	}
 
 	// use kubeletServer to construct the default KubeletDeps
 	kubeletDeps, err := app.UnsecuredDependencies(kubeletServer)

pkg/kubelet/apis/kubeletconfig/BUILD

@@ -36,7 +36,7 @@ filegroup(
     name = "all-srcs",
     srcs = [
         ":package-srcs",
-        "//pkg/kubelet/apis/kubeletconfig/install:all-srcs",
+        "//pkg/kubelet/apis/kubeletconfig/scheme:all-srcs",
         "//pkg/kubelet/apis/kubeletconfig/v1alpha1:all-srcs",
         "//pkg/kubelet/apis/kubeletconfig/validation:all-srcs",
     ],

pkg/kubelet/apis/kubeletconfig/install/BUILD → pkg/kubelet/apis/kubeletconfig/scheme/BUILD

-package(default_visibility = ["//visibility:public"])
-
-licenses(["notice"])
-
-load(
-    "@io_bazel_rules_go//go:def.bzl",
-    "go_library",
-)
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
 
 go_library(
     name = "go_default_library",
-    srcs = ["install.go"],
-    tags = ["automanaged"],
+    srcs = ["scheme.go"],
+    visibility = ["//visibility:public"],
     deps = [
-        "//pkg/api:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig/v1alpha1:go_default_library",
-        "//vendor/k8s.io/apimachinery/pkg/apimachinery/announced:go_default_library",
-        "//vendor/k8s.io/apimachinery/pkg/apimachinery/registered:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime/serializer:go_default_library",
     ],
 )
 
@@ -32,4 +23,5 @@ filegroup(
     name = "all-srcs",
     srcs = [":package-srcs"],
     tags = ["automanaged"],
+    visibility = ["//visibility:public"],
 )

pkg/kubelet/apis/kubeletconfig/install/install.go → pkg/kubelet/apis/kubeletconfig/scheme/scheme.go

@@ -14,36 +14,27 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-// Package install installs the experimental API group, making it available as
-// an option to all of the API encoding/decoding machinery.
-package install
+package scheme
 
 import (
-	"k8s.io/apimachinery/pkg/apimachinery/announced"
-	"k8s.io/apimachinery/pkg/apimachinery/registered"
 	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/v1alpha1"
 )
 
-func init() {
-	// TODO(mtaufen): probably want to create a kubelet scheme rather than reusing the api scheme, but need to ask lavalamp
-	Install(api.GroupFactoryRegistry, api.Registry, api.Scheme)
-}
+// Utility functions for the Kubelet's kubeletconfig API group
 
-// Install registers the API group and adds types to a scheme
-func Install(groupFactoryRegistry announced.APIGroupFactoryRegistry, registry *registered.APIRegistrationManager, scheme *runtime.Scheme) {
-	if err := announced.NewGroupMetaFactory(
-		&announced.GroupMetaFactoryArgs{
-			GroupName:                  kubeletconfig.GroupName,
-			VersionPreferenceOrder:     []string{v1alpha1.SchemeGroupVersion.Version},
-			AddInternalObjectsToScheme: kubeletconfig.AddToScheme,
-		},
-		announced.VersionToSchemeFunc{
-			v1alpha1.SchemeGroupVersion.Version: v1alpha1.AddToScheme,
-		},
-	).Announce(groupFactoryRegistry).RegisterAndEnable(registry, scheme); err != nil {
-		panic(err)
+// NewSchemeAndCodecs is a utility funciton that returns a Scheme and CodecFactory
+// that understand the types in the kubeletconfig API group.
+func NewSchemeAndCodecs() (*runtime.Scheme, *serializer.CodecFactory, error) {
+	scheme := runtime.NewScheme()
+	if err := kubeletconfig.AddToScheme(scheme); err != nil {
+		return nil, nil, err
+	}
+	if err := v1alpha1.AddToScheme(scheme); err != nil {
+		return nil, nil, err
 	}
+	codecs := serializer.NewCodecFactory(scheme)
+	return scheme, &codecs, nil
 }

pkg/kubelet/kubeletconfig/checkpoint/BUILD

@@ -15,8 +15,8 @@ go_test(
     ],
     library = ":go_default_library",
     deps = [
-        "//pkg/api:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
+        "//pkg/kubelet/apis/kubeletconfig/scheme:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig/v1alpha1:go_default_library",
         "//pkg/kubelet/kubeletconfig/util/codec:go_default_library",
         "//pkg/kubelet/kubeletconfig/util/test:go_default_library",
@@ -40,12 +40,14 @@ go_library(
     deps = [
         "//pkg/api:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
+        "//pkg/kubelet/apis/kubeletconfig/scheme:go_default_library",
         "//pkg/kubelet/kubeletconfig/util/codec:go_default_library",
         "//pkg/kubelet/kubeletconfig/util/log:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/api/equality:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime/serializer:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes:go_default_library",
     ],
 )

pkg/kubelet/kubeletconfig/checkpoint/checkpoint.go

@@ -30,7 +30,7 @@ import (
 type Checkpoint interface {
 	// UID returns the UID of the config source object behind the Checkpoint
 	UID() string
-	// Parse parses the checkpoint into the internal KubeletConfiguration type
+	// Parse extracts the KubeletConfiguration from the checkpoint, applies defaults, and converts to the internal type
 	Parse() (*kubeletconfig.KubeletConfiguration, error)
 	// Encode returns a []byte representation of the config source object behind the Checkpoint
 	Encode() ([]byte, error)
@@ -56,6 +56,7 @@ func DecodeCheckpoint(data []byte) (Checkpoint, error) {
 	if err != nil {
 		return nil, fmt.Errorf("failed to convert decoded object into a v1 ConfigMap, error: %v", err)
 	}
+
 	return NewConfigMapCheckpoint(cm)
 }
 

pkg/kubelet/kubeletconfig/checkpoint/checkpoint_test.go

@@ -30,20 +30,6 @@ import (
 	utiltest "k8s.io/kubernetes/pkg/kubelet/kubeletconfig/util/test"
 )
 
-// newUnsupportedEncoded returns an encoding of an object that does not have a Checkpoint implementation
-func newUnsupportedEncoded(t *testing.T) []byte {
-	encoder, err := utilcodec.NewJSONEncoder(apiv1.GroupName)
-	if err != nil {
-		t.Fatalf("could not create an encoder, error: %v", err)
-	}
-	unsupported := &apiv1.Node{}
-	data, err := runtime.Encode(encoder, unsupported)
-	if err != nil {
-		t.Fatalf("could not encode object, error: %v", err)
-	}
-	return data
-}
-
 func TestDecodeCheckpoint(t *testing.T) {
 	// generate correct Checkpoint for v1/ConfigMap test case
 	cm, err := NewConfigMapCheckpoint(&apiv1.ConfigMap{ObjectMeta: metav1.ObjectMeta{UID: types.UID("uid")}})
@@ -87,3 +73,17 @@ func TestDecodeCheckpoint(t *testing.T) {
 		}
 	}
 }
+
+// newUnsupportedEncoded returns an encoding of an object that does not have a Checkpoint implementation
+func newUnsupportedEncoded(t *testing.T) []byte {
+	encoder, err := utilcodec.NewJSONEncoder(apiv1.GroupName)
+	if err != nil {
+		t.Fatalf("could not create an encoder, error: %v", err)
+	}
+	unsupported := &apiv1.Node{}
+	data, err := runtime.Encode(encoder, unsupported)
+	if err != nil {
+		t.Fatalf("could not encode object, error: %v", err)
+	}
+	return data
+}

pkg/kubelet/kubeletconfig/checkpoint/configmap.go

@@ -21,7 +21,9 @@ import (
 
 	apiv1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
+	kubeletscheme "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/scheme"
 	utilcodec "k8s.io/kubernetes/pkg/kubelet/kubeletconfig/util/codec"
 )
 
@@ -29,6 +31,7 @@ const configMapConfigKey = "kubelet"
 
 // configMapCheckpoint implements Checkpoint, backed by a v1/ConfigMap config source object
 type configMapCheckpoint struct {
+	kubeletCodecs *serializer.CodecFactory // codecs for the KubeletConfiguration
 	configMap     *apiv1.ConfigMap
 }
 
@@ -40,7 +43,13 @@ func NewConfigMapCheckpoint(cm *apiv1.ConfigMap) (Checkpoint, error) {
 	} else if len(cm.ObjectMeta.UID) == 0 {
 		return nil, fmt.Errorf("ConfigMap must have a UID to be treated as a Checkpoint")
 	}
-	return &configMapCheckpoint{cm}, nil
+
+	_, kubeletCodecs, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		return nil, err
+	}
+
+	return &configMapCheckpoint{kubeletCodecs, cm}, nil
 }
 
 // UID returns the UID of a configMapCheckpoint
@@ -48,25 +57,23 @@ func (c *configMapCheckpoint) UID() string {
 	return string(c.configMap.UID)
 }
 
-// implements Parse for v1/ConfigMap checkpoints
+// Parse extracts the KubeletConfiguration from v1/ConfigMap checkpoints, applies defaults, and converts to the internal type
 func (c *configMapCheckpoint) Parse() (*kubeletconfig.KubeletConfiguration, error) {
 	const emptyCfgErr = "config was empty, but some parameters are required"
 
-	cm := c.configMap
-
-	if len(cm.Data) == 0 {
+	if len(c.configMap.Data) == 0 {
 		return nil, fmt.Errorf(emptyCfgErr)
 	}
 
 	// TODO(mtaufen): Once the KubeletConfiguration type is decomposed, extend this to a key for each sub-object
-	config, ok := cm.Data[configMapConfigKey]
+	config, ok := c.configMap.Data[configMapConfigKey]
 	if !ok {
 		return nil, fmt.Errorf("key %q not found in ConfigMap", configMapConfigKey)
 	} else if len(config) == 0 {
 		return nil, fmt.Errorf(emptyCfgErr)
 	}
 
-	return utilcodec.DecodeKubeletConfiguration([]byte(config))
+	return utilcodec.DecodeKubeletConfiguration(c.kubeletCodecs, []byte(config))
 }
 
 // Encode encodes a configMapCheckpoint

pkg/kubelet/kubeletconfig/checkpoint/configmap_test.go

@@ -26,8 +26,8 @@ import (
 	apiequality "k8s.io/apimachinery/pkg/api/equality"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
-	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
+	kubeletscheme "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/scheme"
 	kubeletconfigv1alpha1 "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/v1alpha1"
 	utiltest "k8s.io/kubernetes/pkg/kubelet/kubeletconfig/util/test"
 )
@@ -66,9 +66,15 @@ func TestNewConfigMapCheckpoint(t *testing.T) {
 }
 
 func TestConfigMapCheckpointUID(t *testing.T) {
+	_, kubeletCodecs, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
 	cases := []string{"", "uid", "376dfb73-56db-11e7-a01e-42010a800002"}
 	for _, uidIn := range cases {
 		cpt := &configMapCheckpoint{
+			kubeletCodecs,
 			&apiv1.ConfigMap{
 				ObjectMeta: metav1.ObjectMeta{UID: types.UID(uidIn)},
 			},
@@ -82,11 +88,16 @@ func TestConfigMapCheckpointUID(t *testing.T) {
 }
 
 func TestConfigMapCheckpointParse(t *testing.T) {
+	kubeletScheme, kubeletCodecs, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
 	// get the built-in default configuration
 	external := &kubeletconfigv1alpha1.KubeletConfiguration{}
-	api.Scheme.Default(external)
+	kubeletScheme.Default(external)
 	defaultConfig := &kubeletconfig.KubeletConfiguration{}
-	err := api.Scheme.Convert(external, defaultConfig, nil)
+	err = kubeletScheme.Convert(external, defaultConfig, nil)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -123,7 +134,7 @@ apiVersion: kubeletconfig/v1alpha1`}}, defaultConfig, ""},
 			"kubelet": `{"kind":"KubeletConfiguration","apiVersion":"kubeletconfig/v1alpha1"}`}}, defaultConfig, ""},
 	}
 	for _, c := range cases {
-		cpt := &configMapCheckpoint{c.cm}
+		cpt := &configMapCheckpoint{kubeletCodecs, c.cm}
 		kc, err := cpt.Parse()
 		if utiltest.SkipRest(t, c.desc, err, c.err) {
 			continue
@@ -136,6 +147,11 @@ apiVersion: kubeletconfig/v1alpha1`}}, defaultConfig, ""},
 }
 
 func TestConfigMapCheckpointEncode(t *testing.T) {
+	_, kubeletCodecs, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
 	// only one case, based on output from the existing encoder, and since
 	// this is hard to test (key order isn't guaranteed), we should probably
 	// just stick to this test case and mostly rely on the round-trip test.
@@ -146,7 +162,7 @@ func TestConfigMapCheckpointEncode(t *testing.T) {
 	}{
 		// we expect Checkpoints to be encoded as a json representation of the underlying API object
 		{"one-key",
-			&configMapCheckpoint{&apiv1.ConfigMap{
+			&configMapCheckpoint{kubeletCodecs, &apiv1.ConfigMap{
 				ObjectMeta: metav1.ObjectMeta{Name: "one-key"},
 				Data:       map[string]string{"one": ""}}},
 			`{"kind":"ConfigMap","apiVersion":"v1","metadata":{"name":"one-key","creationTimestamp":null},"data":{"one":""}}
@@ -166,6 +182,11 @@ func TestConfigMapCheckpointEncode(t *testing.T) {
 }
 
 func TestConfigMapCheckpointRoundTrip(t *testing.T) {
+	_, kubeletCodecs, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
 	cases := []struct {
 		desc      string
 		cpt       *configMapCheckpoint
@@ -173,7 +194,7 @@ func TestConfigMapCheckpointRoundTrip(t *testing.T) {
 	}{
 		// empty data
 		{"empty data",
-			&configMapCheckpoint{&apiv1.ConfigMap{
+			&configMapCheckpoint{kubeletCodecs, &apiv1.ConfigMap{
 				ObjectMeta: metav1.ObjectMeta{
 					Name: "empty-data-sha256-e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
 					UID:  "uid",
@@ -182,7 +203,7 @@ func TestConfigMapCheckpointRoundTrip(t *testing.T) {
 			""},
 		// two keys
 		{"two keys",
-			&configMapCheckpoint{&apiv1.ConfigMap{
+			&configMapCheckpoint{kubeletCodecs, &apiv1.ConfigMap{
 				ObjectMeta: metav1.ObjectMeta{
 					Name: "two-keys-sha256-2bff03d6249c8a9dc9a1436d087c124741361ccfac6615b81b67afcff5c42431",
 					UID:  "uid",
@@ -191,7 +212,7 @@ func TestConfigMapCheckpointRoundTrip(t *testing.T) {
 			""},
 		// missing uid
 		{"missing uid",
-			&configMapCheckpoint{&apiv1.ConfigMap{
+			&configMapCheckpoint{kubeletCodecs, &apiv1.ConfigMap{
 				ObjectMeta: metav1.ObjectMeta{
 					Name: "two-keys-sha256-2bff03d6249c8a9dc9a1436d087c124741361ccfac6615b81b67afcff5c42431",
 					UID:  "",

pkg/kubelet/kubeletconfig/checkpoint/download.go

@@ -113,7 +113,6 @@ func (r *remoteConfigMap) UID() string {
 
 func (r *remoteConfigMap) Download(client clientset.Interface) (Checkpoint, string, error) {
 	var reason string
-
 	uid := string(r.source.ConfigMapRef.UID)
 
 	utillog.Infof("attempting to download ConfigMap with UID %q", uid)
@@ -131,8 +130,14 @@ func (r *remoteConfigMap) Download(client clientset.Interface) (Checkpoint, stri
 		return nil, reason, fmt.Errorf(reason)
 	}
 
+	checkpoint, err := NewConfigMapCheckpoint(cm)
+	if err != nil {
+		reason = fmt.Sprintf("invalid downloaded object")
+		return nil, reason, fmt.Errorf("%s, error: %v", reason, err)
+	}
+
 	utillog.Infof("successfully downloaded ConfigMap with UID %q", uid)
-	return &configMapCheckpoint{cm}, "", nil
+	return checkpoint, "", nil
 }
 
 func (r *remoteConfigMap) Encode() ([]byte, error) {

pkg/kubelet/kubeletconfig/checkpoint/download_test.go

@@ -26,6 +26,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	fakeclient "k8s.io/client-go/kubernetes/fake"
+	kubeletscheme "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/scheme"
 	utiltest "k8s.io/kubernetes/pkg/kubelet/kubeletconfig/util/test"
 )
 
@@ -92,6 +93,11 @@ func TestRemoteConfigMapUID(t *testing.T) {
 }
 
 func TestRemoteConfigMapDownload(t *testing.T) {
+	_, kubeletCodecs, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
 	cm := &apiv1.ConfigMap{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      "name",
@@ -118,7 +124,7 @@ func TestRemoteConfigMapDownload(t *testing.T) {
 		// successful download
 		{"object exists and reference is correct",
 			&remoteConfigMap{&apiv1.NodeConfigSource{ConfigMapRef: &apiv1.ObjectReference{Name: "name", Namespace: "namespace", UID: "uid"}}},
-			&configMapCheckpoint{cm}, ""},
+			&configMapCheckpoint{kubeletCodecs, cm}, ""},
 	}
 
 	for _, c := range cases {

pkg/kubelet/kubeletconfig/configfiles/BUILD

@@ -10,8 +10,10 @@ go_library(
     srcs = ["configfiles.go"],
     deps = [
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
+        "//pkg/kubelet/apis/kubeletconfig/scheme:go_default_library",
         "//pkg/kubelet/kubeletconfig/util/codec:go_default_library",
         "//pkg/kubelet/kubeletconfig/util/filesystem:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime/serializer:go_default_library",
     ],
 )
 

pkg/kubelet/kubeletconfig/configfiles/configfiles.go

@@ -20,7 +20,9 @@ import (
 	"fmt"
 	"path/filepath"
 
+	"k8s.io/apimachinery/pkg/runtime/serializer"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
+	kubeletscheme "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/scheme"
 	utilcodec "k8s.io/kubernetes/pkg/kubelet/kubeletconfig/util/codec"
 	utilfs "k8s.io/kubernetes/pkg/kubelet/kubeletconfig/util/filesystem"
 )
@@ -35,16 +37,24 @@ type Loader interface {
 type fsLoader struct {
 	// fs is the filesystem where the config files exist; can be mocked for testing
 	fs utilfs.Filesystem
+	// kubeletCodecs is the scheme used to decode config files
+	kubeletCodecs *serializer.CodecFactory
 	// configDir is the absolute path to the directory containing the configuration files
 	configDir string
 }
 
 // NewFSLoader returns a Loader that loads a KubeletConfiguration from the files in `configDir`
-func NewFSLoader(fs utilfs.Filesystem, configDir string) Loader {
+func NewFSLoader(fs utilfs.Filesystem, configDir string) (Loader, error) {
+	_, kubeletCodecs, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		return nil, err
+	}
+
 	return &fsLoader{
 		fs:            fs,
+		kubeletCodecs: kubeletCodecs,
 		configDir:     configDir,
-	}
+	}, nil
 }
 
 func (loader *fsLoader) Load() (*kubeletconfig.KubeletConfiguration, error) {
@@ -62,5 +72,5 @@ func (loader *fsLoader) Load() (*kubeletconfig.KubeletConfiguration, error) {
 		return nil, fmt.Errorf(errfmt, fmt.Errorf("config file was empty, but some parameters are required"))
 	}
 
-	return utilcodec.DecodeKubeletConfiguration(data)
+	return utilcodec.DecodeKubeletConfiguration(loader.kubeletCodecs, data)
 }

pkg/kubelet/kubeletconfig/controller.go

@@ -53,7 +53,7 @@ const (
 // - validates configuration
 // - monitors for potential crash-loops caused by new configurations
 // - tracks the last-known-good configuration, and rolls-back to last-known-good when necessary
-// For more information, see the proposal: https://github.com/kubernetes/kubernetes/pull/29459
+// For more information, see the proposal: https://github.com/kubernetes/community/blob/master/contributors/design-proposals/dynamic-kubelet-configuration.md
 type Controller struct {
 	// dynamicConfig, if true, indicates that we should sync config from the API server
 	dynamicConfig bool
@@ -90,12 +90,19 @@ type Controller struct {
 // If the `initConfigDir` is an empty string, skips trying to load the init config.
 // If the `dynamicConfigDir` is an empty string, skips trying to load checkpoints or download new config,
 // but will still sync the ConfigOK condition if you call StartSync with a non-nil client.
-func NewController(initConfigDir string, dynamicConfigDir string, defaultConfig *kubeletconfig.KubeletConfiguration) *Controller {
+func NewController(initConfigDir string,
+	dynamicConfigDir string,
+	defaultConfig *kubeletconfig.KubeletConfiguration) (*Controller, error) {
+	var err error
+
 	fs := utilfs.DefaultFs{}
 
 	var initLoader configfiles.Loader
 	if len(initConfigDir) > 0 {
-		initLoader = configfiles.NewFSLoader(fs, initConfigDir)
+		initLoader, err = configfiles.NewFSLoader(fs, initConfigDir)
+		if err != nil {
+			return nil, err
+		}
 	}
 	dynamicConfig := false
 	if len(dynamicConfigDir) > 0 {
@@ -120,7 +127,7 @@ func NewController(initConfigDir string, dynamicConfigDir string, defaultConfig
 		badConfigTracker:    badconfig.NewFsTracker(fs, filepath.Join(dynamicConfigDir, badConfigTrackingDir, kubeletVersion)),
 		startupTracker:      startups.NewFsTracker(fs, filepath.Join(dynamicConfigDir, startupTrackingDir, kubeletVersion)),
 		initLoader:          initLoader,
-	}
+	}, nil
 }
 
 // Bootstrap attempts to return a valid KubeletConfiguration based on the configuration of the Controller,

pkg/kubelet/kubeletconfig/util/codec/BUILD

@@ -12,9 +12,8 @@ go_library(
         "//pkg/api:go_default_library",
         "//pkg/api/install:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
-        "//pkg/kubelet/apis/kubeletconfig/install:go_default_library",
-        "//pkg/kubelet/apis/kubeletconfig/v1alpha1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime/serializer:go_default_library",
     ],
 )
 

pkg/kubelet/kubeletconfig/util/codec/codec.go

@@ -21,13 +21,11 @@ import (
 
 	// ensure the core apis are installed
 	_ "k8s.io/kubernetes/pkg/api/install"
-	// ensure the kubeletconfig apis are installed
-	_ "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/install"
 
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
-	kubeletconfigv1alpha1 "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/v1alpha1"
 )
 
 // TODO(mtaufen): allow an encoder to be injected into checkpoint objects at creation time? (then we could ultimately instantiate only one encoder)
@@ -50,28 +48,18 @@ func NewJSONEncoder(groupName string) (runtime.Encoder, error) {
 	return api.Codecs.EncoderForVersion(info.Serializer, versions[0]), nil
 }
 
-// DecodeKubeletConfiguration decodes an encoded (v1alpha1) KubeletConfiguration object to the internal type
-func DecodeKubeletConfiguration(data []byte) (*kubeletconfig.KubeletConfiguration, error) {
-	// decode the object, note we use the external version scheme to decode, because users provide the external version
-	obj, err := runtime.Decode(api.Codecs.UniversalDecoder(kubeletconfigv1alpha1.SchemeGroupVersion), data)
+// DecodeKubeletConfiguration decodes a serialized KubeletConfiguration to the internal type
+func DecodeKubeletConfiguration(kubeletCodecs *serializer.CodecFactory, data []byte) (*kubeletconfig.KubeletConfiguration, error) {
+	// the UniversalDecoder runs defaulting and returns the internal type by default
+	obj, gvk, err := kubeletCodecs.UniversalDecoder().Decode(data, nil, nil)
 	if err != nil {
 		return nil, fmt.Errorf("failed to decode, error: %v", err)
 	}
 
-	externalKC, ok := obj.(*kubeletconfigv1alpha1.KubeletConfiguration)
+	internalKC, ok := obj.(*kubeletconfig.KubeletConfiguration)
 	if !ok {
-		return nil, fmt.Errorf("failed to cast object to KubeletConfiguration, object: %#v", obj)
+		return nil, fmt.Errorf("failed to cast object to KubeletConfiguration, unexpected type: %v", gvk)
 	}
 
-	// TODO(mtaufen): confirm whether api.Codecs.UniversalDecoder runs the defaulting, which would make this redundant
-	// run the defaulter on the decoded configuration before converting to internal type
-	api.Scheme.Default(externalKC)
-
-	// convert to internal type
-	internalKC := &kubeletconfig.KubeletConfiguration{}
-	err = api.Scheme.Convert(externalKC, internalKC, nil)
-	if err != nil {
-		return nil, err
-	}
 	return internalKC, nil
 }

test/e2e_node/BUILD

@@ -30,6 +30,7 @@ go_library(
         "//pkg/kubelet/apis/cri:go_default_library",
         "//pkg/kubelet/apis/cri/v1alpha1/runtime:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
+        "//pkg/kubelet/apis/kubeletconfig/scheme:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig/v1alpha1:go_default_library",
         "//pkg/kubelet/apis/stats/v1alpha1:go_default_library",
         "//pkg/kubelet/metrics:go_default_library",

test/e2e_node/util.go

@@ -37,6 +37,7 @@ import (
 	"k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
+	kubeletscheme "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/scheme"
 	kubeletconfigv1alpha1 "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/v1alpha1"
 	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
 	kubeletmetrics "k8s.io/kubernetes/pkg/kubelet/metrics"
@@ -262,7 +263,7 @@ func makeKubeletConfigMap(internalKC *kubeletconfig.KubeletConfiguration) *v1.Co
 	externalKC := &kubeletconfigv1alpha1.KubeletConfiguration{}
 	api.Scheme.Convert(internalKC, externalKC, nil)
 
-	encoder, err := newJSONEncoder(kubeletconfig.GroupName)
+	encoder, err := newKubeletConfigJSONEncoder()
 	framework.ExpectNoError(err)
 
 	data, err := runtime.Encode(encoder, externalKC)
@@ -310,21 +311,18 @@ func logKubeletMetrics(metricKeys ...string) {
 	}
 }
 
-func newJSONEncoder(groupName string) (runtime.Encoder, error) {
-	// encode to json
+func newKubeletConfigJSONEncoder() (runtime.Encoder, error) {
+	_, kubeletCodecs, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		return nil, err
+	}
+
 	mediaType := "application/json"
-	info, ok := runtime.SerializerInfoForMediaType(api.Codecs.SupportedMediaTypes(), mediaType)
+	info, ok := runtime.SerializerInfoForMediaType(kubeletCodecs.SupportedMediaTypes(), mediaType)
 	if !ok {
 		return nil, fmt.Errorf("unsupported media type %q", mediaType)
 	}
-
-	versions := api.Registry.EnabledVersionsForGroup(groupName)
-	if len(versions) == 0 {
-		return nil, fmt.Errorf("no enabled versions for group %q", groupName)
-	}
-
-	// the "best" version supposedly comes first in the list returned from api.Registry.EnabledVersionsForGroup
-	return api.Codecs.EncoderForVersion(info.Serializer, versions[0]), nil
+	return kubeletCodecs.EncoderForVersion(info.Serializer, kubeletconfigv1alpha1.SchemeGroupVersion), nil
 }
 
 // runCommand runs the cmd and returns the combined stdout and stderr, or an

test/integration/etcd/etcd_storage_path_test.go

@@ -434,10 +434,6 @@ var ephemeralWhiteList = createEphemeralWhiteList(
 	gvr("componentconfig", "v1alpha1", "kubeproxyconfigurations"),     // not stored in etcd
 	// --
 
-	// k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/v1alpha1
-	gvr("kubeletconfig", "v1alpha1", "kubeletconfigurations"), // not stored in etcd
-	// --
-
 	// k8s.io/kubernetes/pkg/apis/extensions/v1beta1
 	gvr("extensions", "v1beta1", "deploymentrollbacks"),          // used to rollback deployment, not stored in etcd
 	gvr("extensions", "v1beta1", "replicationcontrollerdummies"), // not stored in etcd