Add decoding of nested scheduling plugin configs

Signed-off-by: Aldo Culquicondor <acondor@google.com>

pkg/scheduler/apis/config/scheme/BUILD

@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -28,3 +28,19 @@ filegroup(
     tags = ["automanaged"],
     visibility = ["//visibility:public"],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["scheme_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//pkg/scheduler/apis/config:go_default_library",
+        "//staging/src/k8s.io/api/core/v1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
+        "//staging/src/k8s.io/kube-scheduler/config/v1alpha2:go_default_library",
+        "//vendor/github.com/google/go-cmp/cmp:go_default_library",
+        "//vendor/k8s.io/utils/pointer:go_default_library",
+        "//vendor/sigs.k8s.io/yaml:go_default_library",
+    ],
+)

pkg/scheduler/apis/config/scheme/scheme_test.go

@@ -0,0 +1,450 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package scheme
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	v1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/kube-scheduler/config/v1alpha2"
+	"k8s.io/kubernetes/pkg/scheduler/apis/config"
+	"k8s.io/utils/pointer"
+	"sigs.k8s.io/yaml"
+)
+
+func TestCodecsDecodePluginConfig(t *testing.T) {
+	testCases := []struct {
+		name         string
+		data         []byte
+		wantErr      string
+		wantProfiles []config.KubeSchedulerProfile
+	}{
+		{
+			name: "v1alpha2 all plugin args in default profile",
+			data: []byte(`
+apiVersion: kubescheduler.config.k8s.io/v1alpha2
+kind: KubeSchedulerConfiguration
+profiles:
+- pluginConfig:
+  - name: InterPodAffinity
+    args:
+      hardPodAffinityWeight: 5
+  - name: NodeLabel
+    args:
+      presentLabels: ["foo"]
+  - name: NodeResourcesFit
+    args:
+      ignoredResources: ["foo"]
+  - name: RequestedToCapacityRatio
+    args:
+      shape:
+      - utilization: 1
+  - name: PodTopologySpread
+    args:
+      defaultConstraints:
+      - maxSkew: 1
+        topologyKey: zone
+        whenUnsatisfiable: ScheduleAnyway
+  - name: ServiceAffinity
+    args:
+      affinityLabels: ["bar"]
+`),
+			wantProfiles: []config.KubeSchedulerProfile{
+				{
+					SchedulerName: "default-scheduler",
+					PluginConfig: []config.PluginConfig{
+						{
+							Name: "InterPodAffinity",
+							Args: &config.InterPodAffinityArgs{HardPodAffinityWeight: 5},
+						},
+						{
+							Name: "NodeLabel",
+							Args: &config.NodeLabelArgs{PresentLabels: []string{"foo"}},
+						},
+						{
+							Name: "NodeResourcesFit",
+							Args: &config.NodeResourcesFitArgs{IgnoredResources: []string{"foo"}},
+						},
+						{
+							Name: "RequestedToCapacityRatio",
+							Args: &config.RequestedToCapacityRatioArgs{
+								Shape: []config.UtilizationShapePoint{{Utilization: 1}},
+							},
+						},
+						{
+							Name: "PodTopologySpread",
+							Args: &config.PodTopologySpreadArgs{
+								DefaultConstraints: []v1.TopologySpreadConstraint{
+									{MaxSkew: 1, TopologyKey: "zone", WhenUnsatisfiable: v1.ScheduleAnyway},
+								},
+							},
+						},
+						{
+							Name: "ServiceAffinity",
+							Args: &config.ServiceAffinityArgs{
+								AffinityLabels: []string{"bar"},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "v1alpha2 plugins can include version and kind",
+			data: []byte(`
+apiVersion: kubescheduler.config.k8s.io/v1alpha2
+kind: KubeSchedulerConfiguration
+profiles:
+- pluginConfig:
+  - name: NodeLabel
+    args:
+      apiVersion: kubescheduler.config.k8s.io/v1alpha2
+      kind: NodeLabelArgs
+      presentLabels: ["bars"]
+`),
+			wantProfiles: []config.KubeSchedulerProfile{
+				{
+					SchedulerName: "default-scheduler",
+					PluginConfig: []config.PluginConfig{
+						{
+							Name: "NodeLabel",
+							Args: &config.NodeLabelArgs{PresentLabels: []string{"bars"}},
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "plugin group and kind should match the type",
+			data: []byte(`
+apiVersion: kubescheduler.config.k8s.io/v1alpha2
+kind: KubeSchedulerConfiguration
+profiles:
+- pluginConfig:
+  - name: NodeLabel
+    args:
+      apiVersion: kubescheduler.config.k8s.io/v1alpha2
+      kind: InterPodAffinityArgs
+`),
+			wantErr: "decoding .profiles[0].pluginConfig[0]: args for plugin NodeLabel were not of type NodeLabelArgs.kubescheduler.config.k8s.io, got InterPodAffinityArgs.kubescheduler.config.k8s.io",
+		},
+		{
+			// TODO: do not replicate this case for v1beta1.
+			name: "v1alpha2 case insensitive RequestedToCapacityRatioArgs",
+			data: []byte(`
+apiVersion: kubescheduler.config.k8s.io/v1alpha2
+kind: KubeSchedulerConfiguration
+profiles:
+- pluginConfig:
+  - name: RequestedToCapacityRatio
+    args:
+      shape:
+      - utilization: 1
+        score: 2
+      - Utilization: 3
+        Score: 4
+      resources:
+      - name: Upper
+        weight: 1
+      - Name: lower
+        weight: 2
+`),
+			wantProfiles: []config.KubeSchedulerProfile{
+				{
+					SchedulerName: "default-scheduler",
+					PluginConfig: []config.PluginConfig{
+						{
+							Name: "RequestedToCapacityRatio",
+							Args: &config.RequestedToCapacityRatioArgs{
+								Shape: []config.UtilizationShapePoint{
+									{Utilization: 1, Score: 2},
+									{Utilization: 3, Score: 4},
+								},
+								Resources: []config.ResourceSpec{
+									{Name: "Upper", Weight: 1},
+									{Name: "lower", Weight: 2},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "out-of-tree plugin args",
+			data: []byte(`
+apiVersion: kubescheduler.config.k8s.io/v1alpha2
+kind: KubeSchedulerConfiguration
+profiles:
+- pluginConfig:
+  - name: OutOfTreePlugin
+    args:
+      foo: bar
+`),
+			wantProfiles: []config.KubeSchedulerProfile{
+				{
+					SchedulerName: "default-scheduler",
+					PluginConfig: []config.PluginConfig{
+						{
+							Name: "OutOfTreePlugin",
+							Args: &runtime.Unknown{
+								ContentType: "application/json",
+								Raw:         []byte(`{"foo":"bar"}`),
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "empty and no plugin args",
+			data: []byte(`
+apiVersion: kubescheduler.config.k8s.io/v1alpha2
+kind: KubeSchedulerConfiguration
+profiles:
+- pluginConfig:
+  - name: InterPodAffinity
+    args:
+  - name: NodeResourcesFit
+  - name: OutOfTreePlugin
+    args:
+`),
+			wantProfiles: []config.KubeSchedulerProfile{
+				{
+					SchedulerName: "default-scheduler",
+					PluginConfig: []config.PluginConfig{
+						{
+							Name: "InterPodAffinity",
+							// TODO(acondor): Set default values.
+							Args: &config.InterPodAffinityArgs{},
+						},
+						{
+							Name: "NodeResourcesFit",
+							Args: &config.NodeResourcesFitArgs{},
+						},
+						{Name: "OutOfTreePlugin"},
+					},
+				},
+			},
+		},
+	}
+	decoder := Codecs.UniversalDecoder()
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			obj, gvk, err := decoder.Decode(tt.data, nil, nil)
+			if err != nil {
+				if tt.wantErr != err.Error() {
+					t.Fatalf("got err %w, want %w", err, tt.wantErr)
+				}
+				return
+			}
+			if len(tt.wantErr) != 0 {
+				t.Fatal("no error produced, wanted %w", tt.wantErr)
+			}
+			got, ok := obj.(*config.KubeSchedulerConfiguration)
+			if !ok {
+				t.Fatalf("decoded into %s, want %s", gvk, config.SchemeGroupVersion.WithKind("KubeSchedulerConfiguration"))
+			}
+			if diff := cmp.Diff(tt.wantProfiles, got.Profiles); diff != "" {
+				t.Errorf("unexpected configuration (-want,+got):\n%s", diff)
+			}
+		})
+	}
+}
+
+func TestCodecsEncodePluginConfig(t *testing.T) {
+	testCases := []struct {
+		name    string
+		obj     runtime.Object
+		version schema.GroupVersion
+		want    string
+	}{
+		{
+			name:    "v1alpha2 in-tree and out-of-tree plugins",
+			version: v1alpha2.SchemeGroupVersion,
+			obj: &v1alpha2.KubeSchedulerConfiguration{
+				Profiles: []v1alpha2.KubeSchedulerProfile{
+					{
+						PluginConfig: []v1alpha2.PluginConfig{
+							{
+								Name: "InterPodAffinity",
+								Args: runtime.RawExtension{
+									Object: &v1alpha2.InterPodAffinityArgs{
+										HardPodAffinityWeight: pointer.Int32Ptr(5),
+									},
+								},
+							},
+							{
+								Name: "RequestedToCapacityRatio",
+								Args: runtime.RawExtension{
+									Object: &v1alpha2.RequestedToCapacityRatioArgs{
+										Shape: []v1alpha2.UtilizationShapePoint{
+											{Utilization: 1, Score: 2},
+										},
+										Resources: []v1alpha2.ResourceSpec{
+											{Name: "lower", Weight: 2},
+										},
+									},
+								},
+							},
+							{
+								Name: "OutOfTreePlugin",
+								Args: runtime.RawExtension{
+									Raw: []byte(`{"foo":"bar"}`),
+								},
+							},
+						},
+					},
+				},
+			},
+			want: `apiVersion: kubescheduler.config.k8s.io/v1alpha2
+clientConnection:
+  acceptContentTypes: ""
+  burst: 0
+  contentType: ""
+  kubeconfig: ""
+  qps: 0
+kind: KubeSchedulerConfiguration
+leaderElection:
+  leaderElect: null
+  leaseDuration: 0s
+  renewDeadline: 0s
+  resourceLock: ""
+  resourceName: ""
+  resourceNamespace: ""
+  retryPeriod: 0s
+profiles:
+- pluginConfig:
+  - args:
+      apiVersion: kubescheduler.config.k8s.io/v1alpha2
+      hardPodAffinityWeight: 5
+      kind: InterPodAffinityArgs
+    name: InterPodAffinity
+  - args:
+      apiVersion: kubescheduler.config.k8s.io/v1alpha2
+      kind: RequestedToCapacityRatioArgs
+      resources:
+      - Name: lower
+        Weight: 2
+      shape:
+      - Score: 2
+        Utilization: 1
+    name: RequestedToCapacityRatio
+  - args:
+      foo: bar
+    name: OutOfTreePlugin
+`,
+		},
+		{
+			name:    "v1alpha2 in-tree and out-of-tree plugins from internal",
+			version: v1alpha2.SchemeGroupVersion,
+			obj: &config.KubeSchedulerConfiguration{
+				Profiles: []config.KubeSchedulerProfile{
+					{
+						PluginConfig: []config.PluginConfig{
+							{
+								Name: "InterPodAffinity",
+								Args: &config.InterPodAffinityArgs{
+									HardPodAffinityWeight: 5,
+								},
+							},
+							{
+								Name: "OutOfTreePlugin",
+								Args: &runtime.Unknown{
+									Raw: []byte(`{"foo":"bar"}`),
+								},
+							},
+						},
+					},
+				},
+			},
+			want: `apiVersion: kubescheduler.config.k8s.io/v1alpha2
+bindTimeoutSeconds: 0
+clientConnection:
+  acceptContentTypes: ""
+  burst: 0
+  contentType: ""
+  kubeconfig: ""
+  qps: 0
+disablePreemption: false
+enableContentionProfiling: false
+enableProfiling: false
+healthzBindAddress: ""
+kind: KubeSchedulerConfiguration
+leaderElection:
+  leaderElect: false
+  leaseDuration: 0s
+  renewDeadline: 0s
+  resourceLock: ""
+  resourceName: ""
+  resourceNamespace: ""
+  retryPeriod: 0s
+metricsBindAddress: ""
+percentageOfNodesToScore: 0
+podInitialBackoffSeconds: 0
+podMaxBackoffSeconds: 0
+profiles:
+- pluginConfig:
+  - args:
+      apiVersion: kubescheduler.config.k8s.io/v1alpha2
+      hardPodAffinityWeight: 5
+      kind: InterPodAffinityArgs
+    name: InterPodAffinity
+  - args:
+      foo: bar
+    name: OutOfTreePlugin
+  schedulerName: ""
+`,
+		},
+	}
+	yamlInfo, ok := runtime.SerializerInfoForMediaType(Codecs.SupportedMediaTypes(), runtime.ContentTypeYAML)
+	if !ok {
+		t.Fatalf("unable to locate encoder -- %q is not a supported media type", runtime.ContentTypeYAML)
+	}
+	jsonInfo, ok := runtime.SerializerInfoForMediaType(Codecs.SupportedMediaTypes(), runtime.ContentTypeJSON)
+	if !ok {
+		t.Fatalf("unable to locate encoder -- %q is not a supported media type", runtime.ContentTypeJSON)
+	}
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			encoder := Codecs.EncoderForVersion(yamlInfo.Serializer, tt.version)
+			var buf bytes.Buffer
+			if err := encoder.Encode(tt.obj, &buf); err != nil {
+				t.Fatal(err)
+			}
+			if diff := cmp.Diff(tt.want, buf.String()); diff != "" {
+				t.Errorf("unexpected encoded configuration:\n%s", diff)
+			}
+			encoder = Codecs.EncoderForVersion(jsonInfo.Serializer, tt.version)
+			buf = bytes.Buffer{}
+			if err := encoder.Encode(tt.obj, &buf); err != nil {
+				t.Fatal(err)
+			}
+			out, err := yaml.JSONToYAML(buf.Bytes())
+			if err != nil {
+				t.Fatal(err)
+			}
+			if diff := cmp.Diff(tt.want, string(out)); diff != "" {
+				t.Errorf("unexpected encoded configuration:\n%s", diff)
+			}
+		})
+	}
+}

pkg/scheduler/apis/config/v1alpha2/BUILD

@@ -20,6 +20,7 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/conversion:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/runtime:go_default_library",
         "//staging/src/k8s.io/component-base/config/v1alpha1:go_default_library",
         "//staging/src/k8s.io/kube-scheduler/config/v1:go_default_library",
         "//staging/src/k8s.io/kube-scheduler/config/v1alpha2:go_default_library",

pkg/scheduler/apis/config/v1alpha2/conversion.go

@@ -17,20 +17,93 @@ limitations under the License.
 package v1alpha2
 
 import (
-	conversion "k8s.io/apimachinery/pkg/conversion"
-	v1alpha2 "k8s.io/kube-scheduler/config/v1alpha2"
+	"fmt"
+	"sync"
+
+	"k8s.io/apimachinery/pkg/conversion"
+	"k8s.io/apimachinery/pkg/runtime"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/kube-scheduler/config/v1alpha2"
 	"k8s.io/kubernetes/pkg/scheduler/apis/config"
 	"k8s.io/utils/pointer"
 )
 
+var (
+	// pluginArgConversionScheme is a scheme with internal and v1alpha2 registered,
+	// used for defaulting/converting typed PluginConfig Args.
+	// Access via getPluginArgConversionScheme()
+	pluginArgConversionScheme     *runtime.Scheme
+	initPluginArgConversionScheme sync.Once
+)
+
+func getPluginArgConversionScheme() *runtime.Scheme {
+	initPluginArgConversionScheme.Do(func() {
+		// set up the scheme used for plugin arg conversion
+		pluginArgConversionScheme = runtime.NewScheme()
+		utilruntime.Must(AddToScheme(pluginArgConversionScheme))
+		utilruntime.Must(config.AddToScheme(pluginArgConversionScheme))
+	})
+	return pluginArgConversionScheme
+}
+
 func Convert_v1alpha2_KubeSchedulerConfiguration_To_config_KubeSchedulerConfiguration(in *v1alpha2.KubeSchedulerConfiguration, out *config.KubeSchedulerConfiguration, s conversion.Scope) error {
 	if err := autoConvert_v1alpha2_KubeSchedulerConfiguration_To_config_KubeSchedulerConfiguration(in, out, s); err != nil {
 		return err
 	}
 	out.AlgorithmSource.Provider = pointer.StringPtr(v1alpha2.SchedulerDefaultProviderName)
+	return convertToInternalPluginConfigArgs(out)
+}
+
+// convertToInternalPluginConfigArgs converts PluginConfig#Args into internal
+// types using a scheme, after applying defaults.
+func convertToInternalPluginConfigArgs(out *config.KubeSchedulerConfiguration) error {
+	scheme := getPluginArgConversionScheme()
+	for i := range out.Profiles {
+		for j := range out.Profiles[i].PluginConfig {
+			args := out.Profiles[i].PluginConfig[j].Args
+			if args == nil {
+				continue
+			}
+			if _, isUnknown := args.(*runtime.Unknown); isUnknown {
+				continue
+			}
+			scheme.Default(args)
+			internalArgs, err := scheme.ConvertToVersion(args, config.SchemeGroupVersion)
+			if err != nil {
+				return fmt.Errorf("converting .Profiles[%d].PluginConfig[%d].Args into internal type: %w", i, j, err)
+			}
+			out.Profiles[i].PluginConfig[j].Args = internalArgs
+		}
+	}
 	return nil
 }
 
 func Convert_config_KubeSchedulerConfiguration_To_v1alpha2_KubeSchedulerConfiguration(in *config.KubeSchedulerConfiguration, out *v1alpha2.KubeSchedulerConfiguration, s conversion.Scope) error {
-	return autoConvert_config_KubeSchedulerConfiguration_To_v1alpha2_KubeSchedulerConfiguration(in, out, s)
+	if err := autoConvert_config_KubeSchedulerConfiguration_To_v1alpha2_KubeSchedulerConfiguration(in, out, s); err != nil {
+		return err
+	}
+	return convertToExternalPluginConfigArgs(out)
+}
+
+// convertToExternalPluginConfigArgs converts PluginConfig#Args into
+// external (versioned) types using a scheme.
+func convertToExternalPluginConfigArgs(out *v1alpha2.KubeSchedulerConfiguration) error {
+	scheme := getPluginArgConversionScheme()
+	for i := range out.Profiles {
+		for j := range out.Profiles[i].PluginConfig {
+			args := out.Profiles[i].PluginConfig[j].Args
+			if args.Object == nil {
+				continue
+			}
+			if _, isUnknown := args.Object.(*runtime.Unknown); isUnknown {
+				continue
+			}
+			externalArgs, err := scheme.ConvertToVersion(args.Object, SchemeGroupVersion)
+			if err != nil {
+				return err
+			}
+			out.Profiles[i].PluginConfig[j].Args.Object = externalArgs
+		}
+	}
+	return nil
 }

staging/src/k8s.io/kube-scheduler/config/v1alpha2/BUILD

@@ -19,6 +19,7 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
         "//staging/src/k8s.io/component-base/config/v1alpha1:go_default_library",
         "//staging/src/k8s.io/kube-scheduler/config/v1:go_default_library",
+        "//vendor/sigs.k8s.io/yaml:go_default_library",
     ],
 )
 

staging/src/k8s.io/kube-scheduler/config/v1alpha2/types.go

@@ -17,10 +17,14 @@ limitations under the License.
 package v1alpha2
 
 import (
+	"bytes"
+	"fmt"
+
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	componentbaseconfigv1alpha1 "k8s.io/component-base/config/v1alpha1"
 	v1 "k8s.io/kube-scheduler/config/v1"
+	"sigs.k8s.io/yaml"
 )
 
 const (
@@ -73,17 +77,17 @@ type KubeSchedulerConfiguration struct {
 	// Duration to wait for a binding operation to complete before timing out
 	// Value must be non-negative integer. The value zero indicates no waiting.
 	// If this value is nil, the default value will be used.
-	BindTimeoutSeconds *int64 `json:"bindTimeoutSeconds"`
+	BindTimeoutSeconds *int64 `json:"bindTimeoutSeconds,omitempty"`
 
 	// PodInitialBackoffSeconds is the initial backoff for unschedulable pods.
 	// If specified, it must be greater than 0. If this value is null, the default value (1s)
 	// will be used.
-	PodInitialBackoffSeconds *int64 `json:"podInitialBackoffSeconds"`
+	PodInitialBackoffSeconds *int64 `json:"podInitialBackoffSeconds,omitempty"`
 
 	// PodMaxBackoffSeconds is the max backoff for unschedulable pods.
 	// If specified, it must be greater than podInitialBackoffSeconds. If this value is null,
 	// the default value (10s) will be used.
-	PodMaxBackoffSeconds *int64 `json:"podMaxBackoffSeconds"`
+	PodMaxBackoffSeconds *int64 `json:"podMaxBackoffSeconds,omitempty"`
 
 	// Profiles are scheduling profiles that kube-scheduler supports. Pods can
 	// choose to be scheduled under a particular profile by setting its associated
@@ -91,12 +95,40 @@ type KubeSchedulerConfiguration struct {
 	// with the "default-scheduler" profile, if present here.
 	// +listType=map
 	// +listMapKey=schedulerName
-	Profiles []KubeSchedulerProfile `json:"profiles"`
+	Profiles []KubeSchedulerProfile `json:"profiles,omitempty"`
 
 	// Extenders are the list of scheduler extenders, each holding the values of how to communicate
 	// with the extender. These extenders are shared by all scheduler profiles.
 	// +listType=set
-	Extenders []v1.Extender `json:"extenders"`
+	Extenders []v1.Extender `json:"extenders,omitempty"`
+}
+
+// DecodeNestedObjects decodes plugin args for known types.
+func (c *KubeSchedulerConfiguration) DecodeNestedObjects(d runtime.Decoder) error {
+	for i := range c.Profiles {
+		prof := &c.Profiles[i]
+		for j := range prof.PluginConfig {
+			err := prof.PluginConfig[j].decodeNestedObjects(d)
+			if err != nil {
+				return fmt.Errorf("decoding .profiles[%d].pluginConfig[%d]: %w", i, j, err)
+			}
+		}
+	}
+	return nil
+}
+
+// EncodeNestedObjects encodes plugin args.
+func (c *KubeSchedulerConfiguration) EncodeNestedObjects(e runtime.Encoder) error {
+	for i := range c.Profiles {
+		prof := &c.Profiles[i]
+		for j := range prof.PluginConfig {
+			err := prof.PluginConfig[j].encodeNestedObjects(e)
+			if err != nil {
+				return fmt.Errorf("encoding .profiles[%d].pluginConfig[%d]: %w", i, j, err)
+			}
+		}
+	}
+	return nil
 }
 
 // KubeSchedulerProfile is a scheduling profile.
@@ -202,3 +234,41 @@ type PluginConfig struct {
 	// Args defines the arguments passed to the plugins at the time of initialization. Args can have arbitrary structure.
 	Args runtime.RawExtension `json:"args,omitempty"`
 }
+
+func (c *PluginConfig) decodeNestedObjects(d runtime.Decoder) error {
+	gvk := SchemeGroupVersion.WithKind(c.Name + "Args")
+	// dry-run to detect and skip out-of-tree plugin args.
+	if _, _, err := d.Decode(nil, &gvk, nil); runtime.IsNotRegisteredError(err) {
+		return nil
+	}
+
+	obj, parsedGvk, err := d.Decode(c.Args.Raw, &gvk, nil)
+	if err != nil {
+		return fmt.Errorf("decoding args for plugin %s: %w", c.Name, err)
+	}
+	if parsedGvk.GroupKind() != gvk.GroupKind() {
+		return fmt.Errorf("args for plugin %s were not of type %s, got %s", c.Name, gvk.GroupKind(), parsedGvk.GroupKind())
+	}
+	c.Args.Object = obj
+	return nil
+}
+
+func (c *PluginConfig) encodeNestedObjects(e runtime.Encoder) error {
+	if c.Args.Object == nil {
+		return nil
+	}
+	var buf bytes.Buffer
+	err := e.Encode(c.Args.Object, &buf)
+	if err != nil {
+		return err
+	}
+	// The <e> encoder might be a YAML encoder, but the parent encoder expects
+	// JSON output, so we convert YAML back to JSON.
+	// This is a no-op if <e> produces JSON.
+	json, err := yaml.YAMLToJSON(buf.Bytes())
+	if err != nil {
+		return err
+	}
+	c.Args.Raw = json
+	return nil
+}

staging/src/k8s.io/kube-scheduler/config/v1alpha2/types_pluginargs.go

@@ -17,6 +17,8 @@ limitations under the License.
 package v1alpha2
 
 import (
+	gojson "encoding/json"
+
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
@@ -95,7 +97,7 @@ type RequestedToCapacityRatioArgs struct {
 	Resources []ResourceSpec `json:"resources,omitempty"`
 }
 
-// TODO add JSON tags and backward compatible conversion in v1beta1.
+// TODO add JSON tags and remove custom unmarshalling in v1beta1.
 // UtilizationShapePoint and ResourceSpec fields are not annotated with JSON tags in v1alpha2
 // to maintain backward compatibility with the args shipped with v1.18.
 // See https://github.com/kubernetes/kubernetes/pull/88585#discussion_r405021905
@@ -108,6 +110,13 @@ type UtilizationShapePoint struct {
 	Score int32
 }
 
+// UnmarshalJSON provides case insensitive unmarshalling for the type.
+// TODO remove when copying to v1beta1.
+func (t *UtilizationShapePoint) UnmarshalJSON(data []byte) error {
+	type internal *UtilizationShapePoint
+	return gojson.Unmarshal(data, internal(t))
+}
+
 // ResourceSpec represents single resource and weight for bin packing of priority RequestedToCapacityRatioArguments.
 type ResourceSpec struct {
 	// Name of the resource to be managed by RequestedToCapacityRatio function.
@@ -116,6 +125,13 @@ type ResourceSpec struct {
 	Weight int64
 }
 
+// UnmarshalJSON provides case insensitive unmarshalling for the type.
+// TODO remove when copying to v1beta1.
+func (t *ResourceSpec) UnmarshalJSON(data []byte) error {
+	type internal *ResourceSpec
+	return gojson.Unmarshal(data, internal(t))
+}
+
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 
 // ServiceAffinityArgs holds arguments used to configure the ServiceAffinity plugin.

staging/src/k8s.io/kube-scheduler/go.mod

@@ -9,6 +9,7 @@ require (
 	k8s.io/api v0.0.0
 	k8s.io/apimachinery v0.0.0
 	k8s.io/component-base v0.0.0
+	sigs.k8s.io/yaml v1.2.0
 )
 
 replace (