ValidatingAdmissionPolicy controller for Type Checking (#117377)

* [API REVIEW] ValidatingAdmissionPolicyStatucController config.

worker count.

* ValidatingAdmissionPolicyStatus controller.

* remove CEL typechecking from API server.

* fix initializer tests.

* remove type checking integration tests

from API server integration tests.

* validatingadmissionpolicy-status options.

* grant access to VAP controller.

* add defaulting unit test.

* generated: ./hack/update-codegen.sh

* add OWNERS for VAP status controller.

* type checking test case.

api/api-rules/violation_exceptions.list

@@ -531,6 +531,7 @@ API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,K
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,KubeControllerManagerConfiguration,ServiceController
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,KubeControllerManagerConfiguration,StatefulSetController
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,KubeControllerManagerConfiguration,TTLAfterFinishedController
+API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,KubeControllerManagerConfiguration,ValidatingAdmissionPolicyStatusController
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,LegacySATokenCleanerConfiguration,CleanUpPeriod
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,NamespaceControllerConfiguration,ConcurrentNamespaceSyncs
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,NamespaceControllerConfiguration,NamespaceSyncPeriod
@@ -567,6 +568,7 @@ API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,S
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,SAControllerConfiguration,ServiceAccountKeyFile
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,StatefulSetControllerConfiguration,ConcurrentStatefulSetSyncs
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,TTLAfterFinishedControllerConfiguration,ConcurrentTTLSyncs
+API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,ValidatingAdmissionPolicyStatusControllerConfiguration,ConcurrentPolicySyncs
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,VolumeConfiguration,EnableDynamicProvisioning
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,VolumeConfiguration,EnableHostPathProvisioning
 API rule violation: names_match,k8s.io/kube-controller-manager/config/v1alpha1,VolumeConfiguration,FlexVolumePluginDir

cmd/kube-apiserver/app/server.go

@@ -35,7 +35,6 @@ import (
 	utilnet "k8s.io/apimachinery/pkg/util/net"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apiserver/pkg/admission"
-	"k8s.io/apiserver/pkg/cel/openapi/resolver"
 	genericapifilters "k8s.io/apiserver/pkg/endpoints/filters"
 	genericapiserver "k8s.io/apiserver/pkg/server"
 	"k8s.io/apiserver/pkg/server/egressselector"
@@ -45,7 +44,6 @@ import (
 	"k8s.io/client-go/dynamic"
 	clientgoinformers "k8s.io/client-go/informers"
 	clientset "k8s.io/client-go/kubernetes"
-	k8sscheme "k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/util/keyutil"
 	cliflag "k8s.io/component-base/cli/flag"
@@ -285,8 +283,7 @@ func CreateKubeAPIServerConfig(opts options.CompletedOptions) (
 		CloudConfigFile:      opts.CloudProvider.CloudConfigFile,
 	}
 	serviceResolver := buildServiceResolver(opts.EnableAggregatorRouting, genericConfig.LoopbackClientConfig.Host, versionedInformers)
-	schemaResolver := resolver.NewDefinitionsSchemaResolver(k8sscheme.Scheme, genericConfig.OpenAPIConfig.GetDefinitions)
+	pluginInitializers, admissionPostStartHook, err := admissionConfig.New(proxyTransport, genericConfig.EgressSelector, serviceResolver, genericConfig.TracerProvider)
-	pluginInitializers, admissionPostStartHook, err := admissionConfig.New(proxyTransport, genericConfig.EgressSelector, serviceResolver, genericConfig.TracerProvider, schemaResolver)
 	if err != nil {
 		return nil, nil, nil, fmt.Errorf("failed to create admission plugin initializer: %v", err)
 	}

cmd/kube-controller-manager/app/controllermanager.go

@@ -484,6 +484,9 @@ func NewControllerInitializers(loopMode ControllerLoopMode) map[string]InitFunc
 	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.LegacyServiceAccountTokenCleanUp) {
 		register(names.LegacyServiceAccountTokenCleanerController, startLegacySATokenCleaner)
 	}
+	if utilfeature.DefaultFeatureGate.Enabled(genericfeatures.ValidatingAdmissionPolicy) {
+		register("validatingadmissionpolicy-status-controller", startValidatingAdmissionPolicyStatusController)
+	}
 
 	return controllers
 }

cmd/kube-controller-manager/app/options/options.go

@@ -87,6 +87,7 @@ type KubeControllerManagerOptions struct {
 	ResourceQuotaController                   *ResourceQuotaControllerOptions
 	SAController                              *SAControllerOptions
 	TTLAfterFinishedController                *TTLAfterFinishedControllerOptions
+	ValidatingAdmissionPolicyStatusController *ValidatingAdmissionPolicyStatusControllerOptions
 
 	SecureServing  *apiserveroptions.SecureServingOptionsWithLoopback
 	Authentication *apiserveroptions.DelegatingAuthenticationOptions
@@ -186,6 +187,9 @@ func NewKubeControllerManagerOptions() (*KubeControllerManagerOptions, error) {
 		TTLAfterFinishedController: &TTLAfterFinishedControllerOptions{
 			&componentConfig.TTLAfterFinishedController,
 		},
+		ValidatingAdmissionPolicyStatusController: &ValidatingAdmissionPolicyStatusControllerOptions{
+			&componentConfig.ValidatingAdmissionPolicyStatusController,
+		},
 		SecureServing:  apiserveroptions.NewSecureServingOptions().WithLoopback(),
 		Authentication: apiserveroptions.NewDelegatingAuthenticationOptions(),
 		Authorization:  apiserveroptions.NewDelegatingAuthorizationOptions(),
@@ -261,6 +265,7 @@ func (s *KubeControllerManagerOptions) Flags(allControllers []string, disabledBy
 	s.ResourceQuotaController.AddFlags(fss.FlagSet(names.ResourceQuotaController))
 	s.SAController.AddFlags(fss.FlagSet(names.ServiceAccountController))
 	s.TTLAfterFinishedController.AddFlags(fss.FlagSet(names.TTLAfterFinishedController))
+	s.ValidatingAdmissionPolicyStatusController.AddFlags(fss.FlagSet(names.ValidatingAdmissionPolicyStatusController))
 
 	s.Metrics.AddFlags(fss.FlagSet("metrics"))
 	logsapi.AddFlags(s.Logs, fss.FlagSet("logs"))
@@ -359,6 +364,9 @@ func (s *KubeControllerManagerOptions) ApplyTo(c *kubecontrollerconfig.Config, a
 	if err := s.TTLAfterFinishedController.ApplyTo(&c.ComponentConfig.TTLAfterFinishedController); err != nil {
 		return err
 	}
+	if err := s.ValidatingAdmissionPolicyStatusController.ApplyTo(&c.ComponentConfig.ValidatingAdmissionPolicyStatusController); err != nil {
+		return err
+	}
 	if err := s.SecureServing.ApplyTo(&c.SecureServing, &c.LoopbackClientConfig); err != nil {
 		return err
 	}

cmd/kube-controller-manager/app/options/options_test.go

@@ -63,6 +63,7 @@ import (
 	serviceaccountconfig "k8s.io/kubernetes/pkg/controller/serviceaccount/config"
 	statefulsetconfig "k8s.io/kubernetes/pkg/controller/statefulset/config"
 	ttlafterfinishedconfig "k8s.io/kubernetes/pkg/controller/ttlafterfinished/config"
+	validatingadmissionpolicystatusconfig "k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config"
 	attachdetachconfig "k8s.io/kubernetes/pkg/controller/volume/attachdetach/config"
 	ephemeralvolumeconfig "k8s.io/kubernetes/pkg/controller/volume/ephemeral/config"
 	persistentvolumeconfig "k8s.io/kubernetes/pkg/controller/volume/persistentvolume/config"
@@ -101,6 +102,7 @@ var args = []string{
 	"--concurrent-service-syncs=2",
 	"--concurrent-serviceaccount-token-syncs=10",
 	"--concurrent_rc_syncs=10",
+	"--concurrent-validating-admission-policy-status-syncs=9",
 	"--configure-cloud-routes=false",
 	"--contention-profiling=true",
 	"--controller-start-interval=2m",
@@ -409,6 +411,11 @@ func TestAddFlags(t *testing.T) {
 				ConcurrentTTLSyncs: 8,
 			},
 		},
+		ValidatingAdmissionPolicyStatusController: &ValidatingAdmissionPolicyStatusControllerOptions{
+			&validatingadmissionpolicystatusconfig.ValidatingAdmissionPolicyStatusControllerConfiguration{
+				ConcurrentPolicySyncs: 9,
+			},
+		},
 		SecureServing: (&apiserveroptions.SecureServingOptions{
 			BindPort:    10001,
 			BindAddress: netutils.ParseIPSloppy("192.168.4.21"),
@@ -640,6 +647,9 @@ func TestApplyTo(t *testing.T) {
 			TTLAfterFinishedController: ttlafterfinishedconfig.TTLAfterFinishedControllerConfiguration{
 				ConcurrentTTLSyncs: 8,
 			},
+			ValidatingAdmissionPolicyStatusController: validatingadmissionpolicystatusconfig.ValidatingAdmissionPolicyStatusControllerConfiguration{
+				ConcurrentPolicySyncs: 9,
+			},
 		},
 	}
 

cmd/kube-controller-manager/app/options/validatingadmissionpolicycontroller.go

@@ -0,0 +1,63 @@
+/*
+Copyright 2023 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 options
+
+import (
+	"fmt"
+
+	"github.com/spf13/pflag"
+
+	validatingadmissionpolicystatusconfig "k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config"
+)
+
+// ValidatingAdmissionPolicyStatusControllerOptions holds the ValidatingAdmissionPolicyStatusController options.
+type ValidatingAdmissionPolicyStatusControllerOptions struct {
+	*validatingadmissionpolicystatusconfig.ValidatingAdmissionPolicyStatusControllerConfiguration
+}
+
+// AddFlags adds flags related to ValidatingAdmissionPolicyStatusController for controller manager to the specified FlagSet.
+func (o *ValidatingAdmissionPolicyStatusControllerOptions) AddFlags(fs *pflag.FlagSet) {
+	if o == nil {
+		return
+	}
+
+	fs.Int32Var(&o.ConcurrentPolicySyncs, "concurrent-validating-admission-policy-status-syncs", o.ConcurrentPolicySyncs, "The number of ValidatingAdmissionPolicyStatusController workers that are allowed to sync concurrently.")
+}
+
+// ApplyTo fills up ValidatingAdmissionPolicyStatusController config with options.
+func (o *ValidatingAdmissionPolicyStatusControllerOptions) ApplyTo(cfg *validatingadmissionpolicystatusconfig.ValidatingAdmissionPolicyStatusControllerConfiguration) error {
+	if o == nil {
+		return nil
+	}
+
+	cfg.ConcurrentPolicySyncs = o.ConcurrentPolicySyncs
+
+	return nil
+}
+
+// Validate checks validation of ValidatingAdmissionPolicyStatusControllerOptions.
+func (o *ValidatingAdmissionPolicyStatusControllerOptions) Validate() []error {
+	if o == nil {
+		return nil
+	}
+	var errs []error
+	if o.ConcurrentPolicySyncs <= 0 {
+		// omits controller or flag names because the CLI already includes these in the message.
+		errs = append(errs, fmt.Errorf("must be positive, got %d", o.ConcurrentPolicySyncs))
+	}
+	return errs
+}

cmd/kube-controller-manager/app/validatingadmissionpolicystatus.go

@@ -0,0 +1,51 @@
+/*
+Copyright 2023 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 app
+
+import (
+	"context"
+
+	admissionregistrationv1alpha1 "k8s.io/api/admissionregistration/v1alpha1"
+	pluginvalidatingadmissionpolicy "k8s.io/apiserver/pkg/admission/plugin/validatingadmissionpolicy"
+	"k8s.io/apiserver/pkg/cel/openapi/resolver"
+	"k8s.io/client-go/kubernetes/scheme"
+	"k8s.io/controller-manager/controller"
+	"k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus"
+	"k8s.io/kubernetes/pkg/generated/openapi"
+)
+
+var validatingAdmissionPolicyResource = admissionregistrationv1alpha1.SchemeGroupVersion.WithResource("validatingadmissionpolicies")
+
+func startValidatingAdmissionPolicyStatusController(ctx context.Context, controllerContext ControllerContext) (controller.Interface, bool, error) {
+	// intended check against served resource but not feature gate.
+	// KCM won't start the controller without the feature gate set.
+	if !controllerContext.AvailableResources[validatingAdmissionPolicyResource] {
+		return nil, false, nil
+	}
+	typeChecker := &pluginvalidatingadmissionpolicy.TypeChecker{
+		SchemaResolver: resolver.NewDefinitionsSchemaResolver(scheme.Scheme, openapi.GetOpenAPIDefinitions),
+		RestMapper:     controllerContext.RESTMapper,
+	}
+	c, err := validatingadmissionpolicystatus.NewController(
+		controllerContext.InformerFactory.Admissionregistration().V1alpha1().ValidatingAdmissionPolicies(),
+		controllerContext.ClientBuilder.ClientOrDie("validatingadmissionpolicy-status-controller").AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies(),
+		typeChecker,
+	)
+
+	go c.Run(ctx, int(controllerContext.ComponentConfig.ValidatingAdmissionPolicyStatusController.ConcurrentPolicySyncs))
+	return nil, true, err
+}

cmd/kube-controller-manager/names/controller_names.go

@@ -86,6 +86,7 @@ const (
 	StorageVersionGarbageCollectorController     = "storageversion-garbage-collector-controller"
 	ResourceClaimController                      = "resourceclaim-controller"
 	LegacyServiceAccountTokenCleanerController   = "legacy-serviceaccount-token-cleaner-controller"
+	ValidatingAdmissionPolicyStatusController    = "validatingadmissionpolicy-status-controller"
 )
 
 // KCMControllerAliases returns a mapping of aliases to canonical controller names

pkg/controller/apis/config/types.go

@@ -41,6 +41,7 @@ import (
 	serviceaccountconfig "k8s.io/kubernetes/pkg/controller/serviceaccount/config"
 	statefulsetconfig "k8s.io/kubernetes/pkg/controller/statefulset/config"
 	ttlafterfinishedconfig "k8s.io/kubernetes/pkg/controller/ttlafterfinished/config"
+	validatingadmissionpolicystatusconfig "k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config"
 	attachdetachconfig "k8s.io/kubernetes/pkg/controller/volume/attachdetach/config"
 	ephemeralvolumeconfig "k8s.io/kubernetes/pkg/controller/volume/ephemeral/config"
 	persistentvolumeconfig "k8s.io/kubernetes/pkg/controller/volume/persistentvolume/config"
@@ -132,6 +133,9 @@ type KubeControllerManagerConfiguration struct {
 	// TTLAfterFinishedControllerConfiguration holds configuration for
 	// TTLAfterFinishedController related features.
 	TTLAfterFinishedController ttlafterfinishedconfig.TTLAfterFinishedControllerConfiguration
+	// ValidatingAdmissionPolicyStatusControllerConfiguration holds configuration for
+	// ValidatingAdmissionPolicyStatusController related features.
+	ValidatingAdmissionPolicyStatusController validatingadmissionpolicystatusconfig.ValidatingAdmissionPolicyStatusControllerConfiguration
 }
 
 // DeprecatedControllerConfiguration contains elements be deprecated.

pkg/controller/apis/config/v1alpha1/defaults.go

@@ -41,6 +41,7 @@ import (
 	serviceaccountconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/serviceaccount/config/v1alpha1"
 	statefulsetconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/statefulset/config/v1alpha1"
 	ttlafterfinishedconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/ttlafterfinished/config/v1alpha1"
+	validatingadmissionpolicystatusv1alpha1 "k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config/v1alpha1"
 	attachdetachconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/volume/attachdetach/config/v1alpha1"
 	ephemeralvolumeconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/volume/ephemeral/config/v1alpha1"
 	persistentvolumeconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/volume/persistentvolume/config/v1alpha1"
@@ -112,4 +113,6 @@ func SetDefaults_KubeControllerManagerConfiguration(obj *kubectrlmgrconfigv1alph
 	ttlafterfinishedconfigv1alpha1.RecommendedDefaultTTLAfterFinishedControllerConfiguration(&obj.TTLAfterFinishedController)
 	// Use the default RecommendedDefaultPersistentVolumeBinderControllerConfiguration options
 	persistentvolumeconfigv1alpha1.RecommendedDefaultPersistentVolumeBinderControllerConfiguration(&obj.PersistentVolumeBinderController)
+	// Use the default RecommendedDefaultValidatingAdmissionPolicyStatusControllerConfiguration options
+	validatingadmissionpolicystatusv1alpha1.RecommendedDefaultValidatingAdmissionPolicyStatusControllerConfiguration(&obj.ValidatingAdmissionPolicyStatusController)
 }

pkg/controller/apis/config/v1alpha1/zz_generated.conversion.go

@@ -50,6 +50,7 @@ import (
 	serviceaccountconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/serviceaccount/config/v1alpha1"
 	statefulsetconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/statefulset/config/v1alpha1"
 	ttlafterfinishedconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/ttlafterfinished/config/v1alpha1"
+	validatingadmissionpolicystatusconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config/v1alpha1"
 	attachdetachconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/volume/attachdetach/config/v1alpha1"
 	ephemeralconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/volume/ephemeral/config/v1alpha1"
 	persistentvolumeconfigv1alpha1 "k8s.io/kubernetes/pkg/controller/volume/persistentvolume/config/v1alpha1"
@@ -220,6 +221,9 @@ func autoConvert_v1alpha1_KubeControllerManagerConfiguration_To_config_KubeContr
 	if err := ttlafterfinishedconfigv1alpha1.Convert_v1alpha1_TTLAfterFinishedControllerConfiguration_To_config_TTLAfterFinishedControllerConfiguration(&in.TTLAfterFinishedController, &out.TTLAfterFinishedController, s); err != nil {
 		return err
 	}
+	if err := validatingadmissionpolicystatusconfigv1alpha1.Convert_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration_To_config_ValidatingAdmissionPolicyStatusControllerConfiguration(&in.ValidatingAdmissionPolicyStatusController, &out.ValidatingAdmissionPolicyStatusController, s); err != nil {
+		return err
+	}
 	return nil
 }
 
@@ -313,6 +317,9 @@ func autoConvert_config_KubeControllerManagerConfiguration_To_v1alpha1_KubeContr
 	if err := ttlafterfinishedconfigv1alpha1.Convert_config_TTLAfterFinishedControllerConfiguration_To_v1alpha1_TTLAfterFinishedControllerConfiguration(&in.TTLAfterFinishedController, &out.TTLAfterFinishedController, s); err != nil {
 		return err
 	}
+	if err := validatingadmissionpolicystatusconfigv1alpha1.Convert_config_ValidatingAdmissionPolicyStatusControllerConfiguration_To_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration(&in.ValidatingAdmissionPolicyStatusController, &out.ValidatingAdmissionPolicyStatusController, s); err != nil {
+		return err
+	}
 	return nil
 }
 

pkg/controller/apis/config/zz_generated.deepcopy.go

@@ -73,6 +73,7 @@ func (in *KubeControllerManagerConfiguration) DeepCopyInto(out *KubeControllerMa
 	out.SAController = in.SAController
 	out.ServiceController = in.ServiceController
 	out.TTLAfterFinishedController = in.TTLAfterFinishedController
+	out.ValidatingAdmissionPolicyStatusController = in.ValidatingAdmissionPolicyStatusController
 	return
 }
 

pkg/controller/validatingadmissionpolicystatus/OWNERS

@@ -0,0 +1,6 @@
+# See the OWNERS docs at https://go.k8s.io/owners
+
+reviewers:
+  - jiahuif
+labels:
+  - sig/api-machinery

pkg/controller/validatingadmissionpolicystatus/config/doc.go

@@ -0,0 +1,19 @@
+/*
+Copyright 2023 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.
+*/
+
+// +k8s:deepcopy-gen=package
+
+package config // import "k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config"

pkg/controller/validatingadmissionpolicystatus/config/types.go

@@ -0,0 +1,26 @@
+/*
+Copyright 2023 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 config
+
+// ValidatingAdmissionPolicyStatusControllerConfiguration contains elements describing ValidatingAdmissionPolicyStatusController.
+type ValidatingAdmissionPolicyStatusControllerConfiguration struct {
+	// ConcurrentPolicySyncs is the number of policy objects that are
+	// allowed to sync concurrently. Larger number = quicker type checking,
+	// but more CPU (and network) load.
+	// The default value is 5.
+	ConcurrentPolicySyncs int32
+}

pkg/controller/validatingadmissionpolicystatus/config/v1alpha1/conversion.go

@@ -0,0 +1,40 @@
+/*
+Copyright 2023 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 v1alpha1
+
+import (
+	"k8s.io/apimachinery/pkg/conversion"
+	"k8s.io/kube-controller-manager/config/v1alpha1"
+	"k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config"
+)
+
+// Important! The public back-and-forth conversion functions for the types in this package
+// need to be manually exposed like this in order for other packages that reference
+// this package to be able to call these conversion functions in an autogenerated manner.
+// TODO: Fix the bug in conversion-gen so it automatically discovers these Convert_* functions
+// in autogenerated code as well. This is a limitation that affects all controller configurations
+// This issue was introduced in #72800
+
+// Convert_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration_To_config_ValidatingAdmissionPolicyStatusControllerConfiguration is an autogenerated conversion function.
+func Convert_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration_To_config_ValidatingAdmissionPolicyStatusControllerConfiguration(in *v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration, out *config.ValidatingAdmissionPolicyStatusControllerConfiguration, s conversion.Scope) error {
+	return autoConvert_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration_To_config_ValidatingAdmissionPolicyStatusControllerConfiguration(in, out, s)
+}
+
+// Convert_config_ValidatingAdmissionPolicyStatusControllerConfiguration_To_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration is an autogenerated conversion function.
+func Convert_config_ValidatingAdmissionPolicyStatusControllerConfiguration_To_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration(in *config.ValidatingAdmissionPolicyStatusControllerConfiguration, out *v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration, s conversion.Scope) error {
+	return autoConvert_config_ValidatingAdmissionPolicyStatusControllerConfiguration_To_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration(in, out, s)
+}

pkg/controller/validatingadmissionpolicystatus/config/v1alpha1/defaults.go

@@ -0,0 +1,36 @@
+/*
+Copyright 2023 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 v1alpha1
+
+import (
+	kubectrlmgrconfigv1alpha1 "k8s.io/kube-controller-manager/config/v1alpha1"
+)
+
+// RecommendedDefaultValidatingAdmissionPolicyStatusControllerConfiguration defaults a pointer to a
+// ValidatingAdmissionPolicyStatusControllerConfiguration struct. This will set the recommended default
+// values, but they may be subject to change between API versions. This function
+// is intentionally not registered in the scheme as a "normal" `SetDefaults_Foo`
+// function to allow consumers of this type to set whatever defaults for their
+// embedded configs. Forcing consumers to use these defaults would be problematic
+// as defaulting in the scheme is done as part of the conversion, and there would
+// be no easy way to opt-out. Instead, if you want to use this defaulting method
+// run it in your wrapper struct of this type in its `SetDefaults_` method.
+func RecommendedDefaultValidatingAdmissionPolicyStatusControllerConfiguration(obj *kubectrlmgrconfigv1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration) {
+	if obj.ConcurrentPolicySyncs == 0 {
+		obj.ConcurrentPolicySyncs = 5
+	}
+}

pkg/controller/validatingadmissionpolicystatus/config/v1alpha1/defaults_test.go

@@ -0,0 +1,31 @@
+/*
+Copyright 2023 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 v1alpha1
+
+import (
+	"testing"
+
+	kubectrlmgrconfigv1alpha1 "k8s.io/kube-controller-manager/config/v1alpha1"
+)
+
+func TestRecommendedDefaultValidatingAdmissionPolicyStatusControllerConfiguration(t *testing.T) {
+	config := new(kubectrlmgrconfigv1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration)
+	RecommendedDefaultValidatingAdmissionPolicyStatusControllerConfiguration(config)
+	if config.ConcurrentPolicySyncs != 5 {
+		t.Errorf("incorrect default value, expected 5 but got %v", config.ConcurrentPolicySyncs)
+	}
+}

pkg/controller/validatingadmissionpolicystatus/config/v1alpha1/doc.go

@@ -0,0 +1,21 @@
+/*
+Copyright 2023 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.
+*/
+
+// +k8s:deepcopy-gen=package
+// +k8s:conversion-gen=k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config
+// +k8s:conversion-gen-external-types=k8s.io/kube-controller-manager/config/v1alpha1
+
+package v1alpha1 // import "k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config/v1alpha1"

pkg/controller/validatingadmissionpolicystatus/config/v1alpha1/register.go

@@ -0,0 +1,31 @@
+/*
+Copyright 2023 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 v1alpha1
+
+import (
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+var (
+	// SchemeBuilder is the scheme builder with scheme init functions to run for this API package
+	SchemeBuilder runtime.SchemeBuilder
+	// localSchemeBuilder extends the SchemeBuilder instance with the external types. In this package,
+	// defaulting and conversion init funcs are registered as well.
+	localSchemeBuilder = &SchemeBuilder
+	// AddToScheme is a global function that registers this API group & version to a scheme
+	AddToScheme = localSchemeBuilder.AddToScheme
+)

pkg/controller/validatingadmissionpolicystatus/config/v1alpha1/zz_generated.conversion.go

@@ -0,0 +1,92 @@
+//go:build !ignore_autogenerated
+// +build !ignore_autogenerated
+
+/*
+Copyright 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.
+*/
+
+// Code generated by conversion-gen. DO NOT EDIT.
+
+package v1alpha1
+
+import (
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	conversion "k8s.io/apimachinery/pkg/conversion"
+	runtime "k8s.io/apimachinery/pkg/runtime"
+	v1alpha1 "k8s.io/kube-controller-manager/config/v1alpha1"
+	config "k8s.io/kubernetes/pkg/controller/validatingadmissionpolicystatus/config"
+)
+
+func init() {
+	localSchemeBuilder.Register(RegisterConversions)
+}
+
+// RegisterConversions adds conversion functions to the given scheme.
+// Public to allow building arbitrary schemes.
+func RegisterConversions(s *runtime.Scheme) error {
+	if err := s.AddGeneratedConversionFunc((*v1alpha1.GroupResource)(nil), (*v1.GroupResource)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_GroupResource_To_v1_GroupResource(a.(*v1alpha1.GroupResource), b.(*v1.GroupResource), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*v1.GroupResource)(nil), (*v1alpha1.GroupResource)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1_GroupResource_To_v1alpha1_GroupResource(a.(*v1.GroupResource), b.(*v1alpha1.GroupResource), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddConversionFunc((*config.ValidatingAdmissionPolicyStatusControllerConfiguration)(nil), (*v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_config_ValidatingAdmissionPolicyStatusControllerConfiguration_To_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration(a.(*config.ValidatingAdmissionPolicyStatusControllerConfiguration), b.(*v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddConversionFunc((*v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration)(nil), (*config.ValidatingAdmissionPolicyStatusControllerConfiguration)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration_To_config_ValidatingAdmissionPolicyStatusControllerConfiguration(a.(*v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration), b.(*config.ValidatingAdmissionPolicyStatusControllerConfiguration), scope)
+	}); err != nil {
+		return err
+	}
+	return nil
+}
+
+func autoConvert_v1alpha1_GroupResource_To_v1_GroupResource(in *v1alpha1.GroupResource, out *v1.GroupResource, s conversion.Scope) error {
+	out.Group = in.Group
+	out.Resource = in.Resource
+	return nil
+}
+
+// Convert_v1alpha1_GroupResource_To_v1_GroupResource is an autogenerated conversion function.
+func Convert_v1alpha1_GroupResource_To_v1_GroupResource(in *v1alpha1.GroupResource, out *v1.GroupResource, s conversion.Scope) error {
+	return autoConvert_v1alpha1_GroupResource_To_v1_GroupResource(in, out, s)
+}
+
+func autoConvert_v1_GroupResource_To_v1alpha1_GroupResource(in *v1.GroupResource, out *v1alpha1.GroupResource, s conversion.Scope) error {
+	out.Group = in.Group
+	out.Resource = in.Resource
+	return nil
+}
+
+// Convert_v1_GroupResource_To_v1alpha1_GroupResource is an autogenerated conversion function.
+func Convert_v1_GroupResource_To_v1alpha1_GroupResource(in *v1.GroupResource, out *v1alpha1.GroupResource, s conversion.Scope) error {
+	return autoConvert_v1_GroupResource_To_v1alpha1_GroupResource(in, out, s)
+}
+
+func autoConvert_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration_To_config_ValidatingAdmissionPolicyStatusControllerConfiguration(in *v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration, out *config.ValidatingAdmissionPolicyStatusControllerConfiguration, s conversion.Scope) error {
+	out.ConcurrentPolicySyncs = in.ConcurrentPolicySyncs
+	return nil
+}
+
+func autoConvert_config_ValidatingAdmissionPolicyStatusControllerConfiguration_To_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration(in *config.ValidatingAdmissionPolicyStatusControllerConfiguration, out *v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration, s conversion.Scope) error {
+	out.ConcurrentPolicySyncs = in.ConcurrentPolicySyncs
+	return nil
+}

pkg/controller/validatingadmissionpolicystatus/config/v1alpha1/zz_generated.deepcopy.go

@@ -0,0 +1,22 @@
+//go:build !ignore_autogenerated
+// +build !ignore_autogenerated
+
+/*
+Copyright 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.
+*/
+
+// Code generated by deepcopy-gen. DO NOT EDIT.
+
+package v1alpha1

pkg/controller/validatingadmissionpolicystatus/config/zz_generated.deepcopy.go

@@ -0,0 +1,38 @@
+//go:build !ignore_autogenerated
+// +build !ignore_autogenerated
+
+/*
+Copyright 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.
+*/
+
+// Code generated by deepcopy-gen. DO NOT EDIT.
+
+package config
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *ValidatingAdmissionPolicyStatusControllerConfiguration) DeepCopyInto(out *ValidatingAdmissionPolicyStatusControllerConfiguration) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ValidatingAdmissionPolicyStatusControllerConfiguration.
+func (in *ValidatingAdmissionPolicyStatusControllerConfiguration) DeepCopy() *ValidatingAdmissionPolicyStatusControllerConfiguration {
+	if in == nil {
+		return nil
+	}
+	out := new(ValidatingAdmissionPolicyStatusControllerConfiguration)
+	in.DeepCopyInto(out)
+	return out
+}

pkg/controller/validatingadmissionpolicystatus/controller.go

@@ -0,0 +1,162 @@
+/*
+Copyright 2023 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 validatingadmissionpolicystatus
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"k8s.io/api/admissionregistration/v1alpha1"
+	kerrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apiserver/pkg/admission/plugin/validatingadmissionpolicy"
+	admissionregistrationv1alpha1apply "k8s.io/client-go/applyconfigurations/admissionregistration/v1alpha1"
+	informerv1alpha1 "k8s.io/client-go/informers/admissionregistration/v1alpha1"
+	admissionregistrationv1alpha1 "k8s.io/client-go/kubernetes/typed/admissionregistration/v1alpha1"
+	"k8s.io/client-go/tools/cache"
+	"k8s.io/client-go/util/workqueue"
+)
+
+// ControllerName has "Status" in it to differentiate this controller with the other that runs in API server.
+const ControllerName = "validatingadmissionpolicy-status"
+
+// Controller is the ValidatingAdmissionPolicy Status controller that reconciles the Status field of each policy object.
+// This controller runs type checks against referred types for each policy definition.
+type Controller struct {
+	policyInformer informerv1alpha1.ValidatingAdmissionPolicyInformer
+	policyQueue    workqueue.RateLimitingInterface
+	policySynced   cache.InformerSynced
+	policyClient   admissionregistrationv1alpha1.ValidatingAdmissionPolicyInterface
+
+	// typeChecker checks the policy's expressions for type errors.
+	// Type of params is defined in policy.Spec.ParamsKind
+	// Types of object are calculated from policy.Spec.MatchingConstraints
+	typeChecker *validatingadmissionpolicy.TypeChecker
+}
+
+func (c *Controller) Run(ctx context.Context, workers int) {
+	defer utilruntime.HandleCrash()
+
+	if !cache.WaitForNamedCacheSync(ControllerName, ctx.Done(), c.policySynced) {
+		return
+	}
+
+	defer c.policyQueue.ShutDown()
+	for i := 0; i < workers; i++ {
+		go wait.UntilWithContext(ctx, c.runWorker, time.Second)
+	}
+
+	<-ctx.Done()
+}
+
+func NewController(policyInformer informerv1alpha1.ValidatingAdmissionPolicyInformer, policyClient admissionregistrationv1alpha1.ValidatingAdmissionPolicyInterface, typeChecker *validatingadmissionpolicy.TypeChecker) (*Controller, error) {
+	c := &Controller{
+		policyInformer: policyInformer,
+		policyQueue:    workqueue.NewRateLimitingQueueWithConfig(workqueue.DefaultControllerRateLimiter(), workqueue.RateLimitingQueueConfig{Name: ControllerName}),
+		policyClient:   policyClient,
+		typeChecker:    typeChecker,
+	}
+	reg, err := policyInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
+		AddFunc: func(obj interface{}) {
+			c.enqueuePolicy(obj)
+		},
+		UpdateFunc: func(oldObj, newObj interface{}) {
+			c.enqueuePolicy(newObj)
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+	c.policySynced = reg.HasSynced
+	return c, nil
+}
+
+func (c *Controller) enqueuePolicy(policy any) {
+	if policy, ok := policy.(*v1alpha1.ValidatingAdmissionPolicy); ok {
+		// policy objects are cluster-scoped, no point include its namespace.
+		key := policy.ObjectMeta.Name
+		if key == "" {
+			utilruntime.HandleError(fmt.Errorf("cannot get name of object %v", policy))
+		}
+		c.policyQueue.Add(key)
+	}
+}
+
+func (c *Controller) runWorker(ctx context.Context) {
+	for c.processNextWorkItem(ctx) {
+	}
+}
+
+func (c *Controller) processNextWorkItem(ctx context.Context) bool {
+	key, shutdown := c.policyQueue.Get()
+	if shutdown {
+		return false
+	}
+	defer c.policyQueue.Done(key)
+
+	err := func() error {
+		key, ok := key.(string)
+		if !ok {
+			return fmt.Errorf("expect a string but got %v", key)
+		}
+		policy, err := c.policyInformer.Lister().Get(key)
+		if err != nil {
+			if kerrors.IsNotFound(err) {
+				// If not found, the policy is being deleting, do nothing.
+				return nil
+			}
+			return err
+		}
+		return c.reconcile(ctx, policy)
+	}()
+
+	if err == nil {
+		c.policyQueue.Forget(key)
+		return true
+	}
+
+	utilruntime.HandleError(err)
+	c.policyQueue.AddRateLimited(key)
+
+	return true
+}
+
+func (c *Controller) reconcile(ctx context.Context, policy *v1alpha1.ValidatingAdmissionPolicy) error {
+	if policy == nil {
+		return nil
+	}
+	if policy.Generation <= policy.Status.ObservedGeneration {
+		return nil
+	}
+	warnings := c.typeChecker.Check(policy)
+	warningsConfig := make([]*admissionregistrationv1alpha1apply.ExpressionWarningApplyConfiguration, 0, len(warnings))
+	for _, warning := range warnings {
+		warningsConfig = append(warningsConfig, admissionregistrationv1alpha1apply.ExpressionWarning().
+			WithFieldRef(warning.FieldRef).
+			WithWarning(warning.Warning))
+	}
+	applyConfig := admissionregistrationv1alpha1apply.ValidatingAdmissionPolicy(policy.Name).
+		WithStatus(admissionregistrationv1alpha1apply.ValidatingAdmissionPolicyStatus().
+			WithObservedGeneration(policy.Generation).
+			WithTypeChecking(admissionregistrationv1alpha1apply.TypeChecking().
+				WithExpressionWarnings(warningsConfig...)))
+	_, err := c.policyClient.ApplyStatus(ctx, applyConfig, metav1.ApplyOptions{FieldManager: ControllerName, Force: true})
+	return err
+}

pkg/controller/validatingadmissionpolicystatus/controller_test.go

@@ -0,0 +1,224 @@
+/*
+Copyright 2023 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 validatingadmissionpolicystatus
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+
+	admissionregistrationv1 "k8s.io/api/admissionregistration/v1"
+	admissionregistrationv1alpha1 "k8s.io/api/admissionregistration/v1alpha1"
+	"k8s.io/apimachinery/pkg/api/meta/testrestmapper"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apiserver/pkg/admission/plugin/validatingadmissionpolicy"
+	"k8s.io/apiserver/pkg/cel/openapi/resolver"
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes/fake"
+	"k8s.io/client-go/kubernetes/scheme"
+	"k8s.io/kubernetes/pkg/generated/openapi"
+)
+
+func TestTypeChecking(t *testing.T) {
+	for _, tc := range []struct {
+		name           string
+		policy         *admissionregistrationv1alpha1.ValidatingAdmissionPolicy
+		assertFieldRef func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) // warning.fieldRef
+		assertWarnings func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) // warning.warning
+	}{
+		{
+			name: "deployment with correct expression",
+			policy: withGVRMatch([]string{"apps"}, []string{"v1"}, []string{"deployments"}, withValidations([]admissionregistrationv1alpha1.Validation{
+				{
+					Expression: "object.spec.replicas > 1",
+				},
+			}, makePolicy("replicated-deployment"))),
+			assertFieldRef: toHaveLengthOf(0),
+			assertWarnings: toHaveLengthOf(0),
+		},
+		{
+			name: "deployment with type confusion",
+			policy: withGVRMatch([]string{"apps"}, []string{"v1"}, []string{"deployments"}, withValidations([]admissionregistrationv1alpha1.Validation{
+				{
+					Expression: "object.spec.replicas < 100", // this one passes
+				},
+				{
+					Expression: "object.spec.replicas > '1'", // '1' should be int
+				},
+			}, makePolicy("confused-deployment"))),
+			assertFieldRef: toBe("spec.validations[1].expression"),
+			assertWarnings: toHaveSubstring(`found no matching overload for '_>_' applied to '(int, string)'`),
+		},
+		{
+			name: "two expressions different type checking errors",
+			policy: withGVRMatch([]string{"apps"}, []string{"v1"}, []string{"deployments"}, withValidations([]admissionregistrationv1alpha1.Validation{
+				{
+					Expression: "object.spec.nonExistingFirst > 1",
+				},
+				{
+					Expression: "object.spec.replicas > '1'", // '1' should be int
+				},
+			}, makePolicy("confused-deployment"))),
+			assertFieldRef: toBe("spec.validations[0].expression", "spec.validations[1].expression"),
+			assertWarnings: toHaveSubstring(
+				"undefined field 'nonExistingFirst'",
+				`found no matching overload for '_>_' applied to '(int, string)'`,
+			),
+		},
+		{
+			name: "one expression, two warnings",
+			policy: withGVRMatch([]string{"apps"}, []string{"v1"}, []string{"deployments"}, withValidations([]admissionregistrationv1alpha1.Validation{
+				{
+					Expression: "object.spec.replicas < 100", // this one passes
+				},
+				{
+					Expression: "object.spec.replicas > '1' && object.spec.nonExisting == 1",
+				},
+			}, makePolicy("confused-deployment"))),
+			assertFieldRef: toBe("spec.validations[1].expression"),
+			assertWarnings: toHaveMultipleSubstrings([]string{"undefined field 'nonExisting'", `found no matching overload for '_>_' applied to '(int, string)'`}),
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+			defer cancel()
+			policy := tc.policy.DeepCopy()
+			policy.ObjectMeta.Generation = 1 // fake storage does not do this automatically
+			client := fake.NewSimpleClientset(policy)
+			informerFactory := informers.NewSharedInformerFactory(client, 0)
+			typeChecker := &validatingadmissionpolicy.TypeChecker{
+				SchemaResolver: resolver.NewDefinitionsSchemaResolver(scheme.Scheme, openapi.GetOpenAPIDefinitions),
+				RestMapper:     testrestmapper.TestOnlyStaticRESTMapper(scheme.Scheme),
+			}
+			controller, err := NewController(
+				informerFactory.Admissionregistration().V1alpha1().ValidatingAdmissionPolicies(),
+				client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies(),
+				typeChecker,
+			)
+			if err != nil {
+				t.Fatalf("cannot create controller: %v", err)
+			}
+			go informerFactory.Start(ctx.Done())
+			go controller.Run(ctx, 1)
+			err = wait.PollUntilContextCancel(ctx, time.Second, false, func(ctx context.Context) (done bool, err error) {
+				name := policy.Name
+				// wait until the typeChecking is set, which means the type checking
+				// is complete.
+				updated, err := client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Get(ctx, name, metav1.GetOptions{})
+				if err != nil {
+					return false, err
+				}
+				if updated.Status.TypeChecking != nil {
+					policy = updated
+					return true, nil
+				}
+				return false, nil
+			})
+			if err != nil {
+				t.Fatal(err)
+			}
+			tc.assertFieldRef(policy.Status.TypeChecking.ExpressionWarnings, t)
+			tc.assertWarnings(policy.Status.TypeChecking.ExpressionWarnings, t)
+			if err != nil {
+				t.Fatalf("failed to initialize controller: %v", err)
+			}
+		})
+	}
+
+}
+
+func toBe(expected ...string) func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
+	return func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
+		if len(expected) != len(warnings) {
+			t.Fatalf("mismatched length, expect %d, got %d", len(expected), len(warnings))
+		}
+		for i := range expected {
+			if expected[i] != warnings[i].FieldRef {
+				t.Errorf("expected %q but got %q", expected[i], warnings[i].FieldRef)
+			}
+		}
+	}
+}
+
+func toHaveSubstring(substrings ...string) func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
+	return func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
+		if len(substrings) != len(warnings) {
+			t.Fatalf("mismatched length, expect %d, got %d", len(substrings), len(warnings))
+		}
+		for i := range substrings {
+			if !strings.Contains(warnings[i].Warning, substrings[i]) {
+				t.Errorf("missing expected substring %q in %v", substrings[i], warnings[i])
+			}
+		}
+	}
+}
+
+func toHaveMultipleSubstrings(substrings ...[]string) func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
+	return func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
+		if len(substrings) != len(warnings) {
+			t.Fatalf("mismatched length, expect %d, got %d", len(substrings), len(warnings))
+		}
+		for i, expectedSubstrings := range substrings {
+			for _, s := range expectedSubstrings {
+				if !strings.Contains(warnings[i].Warning, s) {
+					t.Errorf("missing expected substring %q in %v", substrings[i], warnings[i])
+				}
+			}
+		}
+	}
+}
+
+func toHaveLengthOf(n int) func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
+	return func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
+		if n != len(warnings) {
+			t.Fatalf("mismatched length, expect %d, got %d", n, len(warnings))
+		}
+	}
+}
+
+func withGVRMatch(groups []string, versions []string, resources []string, policy *admissionregistrationv1alpha1.ValidatingAdmissionPolicy) *admissionregistrationv1alpha1.ValidatingAdmissionPolicy {
+	policy.Spec.MatchConstraints = &admissionregistrationv1alpha1.MatchResources{
+		ResourceRules: []admissionregistrationv1alpha1.NamedRuleWithOperations{
+			{
+				RuleWithOperations: admissionregistrationv1alpha1.RuleWithOperations{
+					Operations: []admissionregistrationv1.OperationType{
+						"*",
+					},
+					Rule: admissionregistrationv1.Rule{
+						APIGroups:   groups,
+						APIVersions: versions,
+						Resources:   resources,
+					},
+				},
+			},
+		},
+	}
+	return policy
+}
+
+func withValidations(validations []admissionregistrationv1alpha1.Validation, policy *admissionregistrationv1alpha1.ValidatingAdmissionPolicy) *admissionregistrationv1alpha1.ValidatingAdmissionPolicy {
+	policy.Spec.Validations = validations
+	return policy
+}
+
+func makePolicy(name string) *admissionregistrationv1alpha1.ValidatingAdmissionPolicy {
+	return &admissionregistrationv1alpha1.ValidatingAdmissionPolicy{
+		ObjectMeta: metav1.ObjectMeta{Name: name},
+	}
+}

pkg/generated/openapi/zz_generated.openapi.go

@@ -1078,6 +1078,7 @@ func GetOpenAPIDefinitions(ref common.ReferenceCallback) map[string]common.OpenA
 		"k8s.io/kube-controller-manager/config/v1alpha1.SAControllerConfiguration":                              schema_k8sio_kube_controller_manager_config_v1alpha1_SAControllerConfiguration(ref),
 		"k8s.io/kube-controller-manager/config/v1alpha1.StatefulSetControllerConfiguration":                     schema_k8sio_kube_controller_manager_config_v1alpha1_StatefulSetControllerConfiguration(ref),
 		"k8s.io/kube-controller-manager/config/v1alpha1.TTLAfterFinishedControllerConfiguration":                schema_k8sio_kube_controller_manager_config_v1alpha1_TTLAfterFinishedControllerConfiguration(ref),
+		"k8s.io/kube-controller-manager/config/v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration": schema_k8sio_kube_controller_manager_config_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration(ref),
 		"k8s.io/kube-controller-manager/config/v1alpha1.VolumeConfiguration":                                    schema_k8sio_kube_controller_manager_config_v1alpha1_VolumeConfiguration(ref),
 		"k8s.io/kube-proxy/config/v1alpha1.DetectLocalConfiguration":                                            schema_k8sio_kube_proxy_config_v1alpha1_DetectLocalConfiguration(ref),
 		"k8s.io/kube-proxy/config/v1alpha1.KubeProxyConfiguration":                                              schema_k8sio_kube_proxy_config_v1alpha1_KubeProxyConfiguration(ref),
@@ -53218,12 +53219,19 @@ func schema_k8sio_kube_controller_manager_config_v1alpha1_KubeControllerManagerC
 							Ref:         ref("k8s.io/kube-controller-manager/config/v1alpha1.TTLAfterFinishedControllerConfiguration"),
 						},
 					},
+					"ValidatingAdmissionPolicyStatusController": {
+						SchemaProps: spec.SchemaProps{
+							Description: "ValidatingAdmissionPolicyStatusControllerConfiguration holds configuration for ValidatingAdmissionPolicyStatusController related features.",
+							Default:     map[string]interface{}{},
+							Ref:         ref("k8s.io/kube-controller-manager/config/v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration"),
 						},
-				Required: []string{"Generic", "KubeCloudShared", "AttachDetachController", "CSRSigningController", "DaemonSetController", "DeploymentController", "StatefulSetController", "DeprecatedController", "EndpointController", "EndpointSliceController", "EndpointSliceMirroringController", "EphemeralVolumeController", "GarbageCollectorController", "HPAController", "JobController", "CronJobController", "LegacySATokenCleaner", "NamespaceController", "NodeIPAMController", "NodeLifecycleController", "PersistentVolumeBinderController", "PodGCController", "ReplicaSetController", "ReplicationController", "ResourceQuotaController", "SAController", "ServiceController", "TTLAfterFinishedController"},
+					},
+				},
+				Required: []string{"Generic", "KubeCloudShared", "AttachDetachController", "CSRSigningController", "DaemonSetController", "DeploymentController", "StatefulSetController", "DeprecatedController", "EndpointController", "EndpointSliceController", "EndpointSliceMirroringController", "EphemeralVolumeController", "GarbageCollectorController", "HPAController", "JobController", "CronJobController", "LegacySATokenCleaner", "NamespaceController", "NodeIPAMController", "NodeLifecycleController", "PersistentVolumeBinderController", "PodGCController", "ReplicaSetController", "ReplicationController", "ResourceQuotaController", "SAController", "ServiceController", "TTLAfterFinishedController", "ValidatingAdmissionPolicyStatusController"},
 			},
 		},
 		Dependencies: []string{
-			"k8s.io/cloud-provider/config/v1alpha1.KubeCloudSharedConfiguration", "k8s.io/cloud-provider/controllers/service/config/v1alpha1.ServiceControllerConfiguration", "k8s.io/controller-manager/config/v1alpha1.GenericControllerManagerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.AttachDetachControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.CSRSigningControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.CronJobControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.DaemonSetControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.DeploymentControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.DeprecatedControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.EndpointControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.EndpointSliceControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.EndpointSliceMirroringControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.EphemeralVolumeControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.GarbageCollectorControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.HPAControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.JobControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.LegacySATokenCleanerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.NamespaceControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.NodeIPAMControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.NodeLifecycleControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.PersistentVolumeBinderControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.PodGCControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.ReplicaSetControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.ReplicationControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.ResourceQuotaControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.SAControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.StatefulSetControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.TTLAfterFinishedControllerConfiguration"},
+			"k8s.io/cloud-provider/config/v1alpha1.KubeCloudSharedConfiguration", "k8s.io/cloud-provider/controllers/service/config/v1alpha1.ServiceControllerConfiguration", "k8s.io/controller-manager/config/v1alpha1.GenericControllerManagerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.AttachDetachControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.CSRSigningControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.CronJobControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.DaemonSetControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.DeploymentControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.DeprecatedControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.EndpointControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.EndpointSliceControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.EndpointSliceMirroringControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.EphemeralVolumeControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.GarbageCollectorControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.HPAControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.JobControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.LegacySATokenCleanerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.NamespaceControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.NodeIPAMControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.NodeLifecycleControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.PersistentVolumeBinderControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.PodGCControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.ReplicaSetControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.ReplicationControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.ResourceQuotaControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.SAControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.StatefulSetControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.TTLAfterFinishedControllerConfiguration", "k8s.io/kube-controller-manager/config/v1alpha1.ValidatingAdmissionPolicyStatusControllerConfiguration"},
 	}
 }
 
@@ -53705,6 +53713,28 @@ func schema_k8sio_kube_controller_manager_config_v1alpha1_TTLAfterFinishedContro
 	}
 }
 
+func schema_k8sio_kube_controller_manager_config_v1alpha1_ValidatingAdmissionPolicyStatusControllerConfiguration(ref common.ReferenceCallback) common.OpenAPIDefinition {
+	return common.OpenAPIDefinition{
+		Schema: spec.Schema{
+			SchemaProps: spec.SchemaProps{
+				Description: "ValidatingAdmissionPolicyStatusControllerConfiguration contains elements describing ValidatingAdmissionPolicyStatusController.",
+				Type:        []string{"object"},
+				Properties: map[string]spec.Schema{
+					"ConcurrentPolicySyncs": {
+						SchemaProps: spec.SchemaProps{
+							Description: "ConcurrentPolicySyncs is the number of policy objects that are allowed to sync concurrently. Larger number = quicker type checking, but more CPU (and network) load. The default value is 5.",
+							Default:     0,
+							Type:        []string{"integer"},
+							Format:      "int32",
+						},
+					},
+				},
+				Required: []string{"ConcurrentPolicySyncs"},
+			},
+		},
+	}
+}
+
 func schema_k8sio_kube_controller_manager_config_v1alpha1_VolumeConfiguration(ref common.ReferenceCallback) common.OpenAPIDefinition {
 	return common.OpenAPIDefinition{
 		Schema: spec.Schema{

pkg/kubeapiserver/admission/config.go

@@ -28,7 +28,6 @@ import (
 	utilwait "k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/apiserver/pkg/admission"
 	webhookinit "k8s.io/apiserver/pkg/admission/plugin/webhook/initializer"
-	"k8s.io/apiserver/pkg/cel/openapi/resolver"
 	genericapiserver "k8s.io/apiserver/pkg/server"
 	egressselector "k8s.io/apiserver/pkg/server/egressselector"
 	"k8s.io/apiserver/pkg/util/webhook"
@@ -48,7 +47,7 @@ type Config struct {
 }
 
 // New sets up the plugins and admission start hooks needed for admission
-func (c *Config) New(proxyTransport *http.Transport, egressSelector *egressselector.EgressSelector, serviceResolver webhook.ServiceResolver, tp trace.TracerProvider, schemaResolver resolver.SchemaResolver) ([]admission.PluginInitializer, genericapiserver.PostStartHookFunc, error) {
+func (c *Config) New(proxyTransport *http.Transport, egressSelector *egressselector.EgressSelector, serviceResolver webhook.ServiceResolver, tp trace.TracerProvider) ([]admission.PluginInitializer, genericapiserver.PostStartHookFunc, error) {
 	webhookAuthResolverWrapper := webhook.NewDefaultAuthenticationInfoResolverWrapper(proxyTransport, egressSelector, c.LoopbackClientConfig, tp)
 	webhookPluginInitializer := webhookinit.NewPluginInitializer(webhookAuthResolverWrapper, serviceResolver)
 
@@ -70,7 +69,6 @@ func (c *Config) New(proxyTransport *http.Transport, egressSelector *egressselec
 		cloudConfig,
 		discoveryRESTMapper,
 		quotainstall.NewQuotaConfigurationForAdmission(),
-		schemaResolver,
 	)
 
 	admissionPostStartHook := func(context genericapiserver.PostStartHookContext) error {

pkg/kubeapiserver/admission/initializer.go

@@ -20,7 +20,6 @@ import (
 	"k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apiserver/pkg/admission"
 	"k8s.io/apiserver/pkg/admission/initializer"
-	"k8s.io/apiserver/pkg/cel/openapi/resolver"
 	quota "k8s.io/apiserver/pkg/quota/v1"
 )
 
@@ -36,7 +35,6 @@ type PluginInitializer struct {
 	cloudConfig        []byte
 	restMapper         meta.RESTMapper
 	quotaConfiguration quota.Configuration
-	schemaResolver     resolver.SchemaResolver
 }
 
 var _ admission.PluginInitializer = &PluginInitializer{}
@@ -48,13 +46,11 @@ func NewPluginInitializer(
 	cloudConfig []byte,
 	restMapper meta.RESTMapper,
 	quotaConfiguration quota.Configuration,
-	schemaResolver resolver.SchemaResolver,
 ) *PluginInitializer {
 	return &PluginInitializer{
 		cloudConfig:        cloudConfig,
 		restMapper:         restMapper,
 		quotaConfiguration: quotaConfiguration,
-		schemaResolver:     schemaResolver,
 	}
 }
 
@@ -72,8 +68,4 @@ func (i *PluginInitializer) Initialize(plugin admission.Interface) {
 	if wants, ok := plugin.(initializer.WantsQuotaConfiguration); ok {
 		wants.SetQuotaConfiguration(i.quotaConfiguration)
 	}
-
-	if wants, ok := plugin.(initializer.WantsSchemaResolver); ok {
-		wants.SetSchemaResolver(i.schemaResolver)
-	}
 }

pkg/kubeapiserver/admission/initializer_test.go

@@ -49,7 +49,7 @@ func (p *WantsCloudConfigAdmissionPlugin) SetCloudConfig(cloudConfig []byte) {
 
 func TestCloudConfigAdmissionPlugin(t *testing.T) {
 	cloudConfig := []byte("cloud-configuration")
-	initializer := NewPluginInitializer(cloudConfig, nil, nil, nil)
+	initializer := NewPluginInitializer(cloudConfig, nil, nil)
 	wantsCloudConfigAdmission := &WantsCloudConfigAdmissionPlugin{}
 	initializer.Initialize(wantsCloudConfigAdmission)
 
@@ -94,7 +94,7 @@ func (p *WantsRESTMapperAdmissionPlugin) SetRESTMapper(mapper meta.RESTMapper) {
 
 func TestRESTMapperAdmissionPlugin(t *testing.T) {
 	mapper := doNothingRESTMapper{}
-	initializer := NewPluginInitializer(nil, mapper, nil, nil)
+	initializer := NewPluginInitializer(nil, mapper, nil)
 	wantsRESTMapperAdmission := &WantsRESTMapperAdmissionPlugin{}
 	initializer.Initialize(wantsRESTMapperAdmission)
 
@@ -121,7 +121,7 @@ func (p *WantsQuotaConfigurationAdmissionPlugin) SetQuotaConfiguration(config qu
 
 func TestQuotaConfigurationAdmissionPlugin(t *testing.T) {
 	config := doNothingQuotaConfiguration{}
-	initializer := NewPluginInitializer(nil, nil, config, nil)
+	initializer := NewPluginInitializer(nil, nil, config)
 	wantsQuotaConfigurationAdmission := &WantsQuotaConfigurationAdmissionPlugin{}
 	initializer.Initialize(wantsQuotaConfigurationAdmission)
 

plugin/pkg/admission/gc/gc_admission_test.go

@@ -139,7 +139,7 @@ func newGCPermissionsEnforcement() (*gcPermissionsEnforcement, error) {
 		return nil, fmt.Errorf("unexpected error while constructing resource list from fake discovery client: %v", err)
 	}
 	restMapper := restmapper.NewDiscoveryRESTMapper(restMapperRes)
-	pluginInitializer := kubeadmission.NewPluginInitializer(nil, restMapper, nil, nil)
+	pluginInitializer := kubeadmission.NewPluginInitializer(nil, restMapper, nil)
 	initializersChain := admission.PluginInitializers{}
 	initializersChain = append(initializersChain, genericPluginInitializer)
 	initializersChain = append(initializersChain, pluginInitializer)

plugin/pkg/admission/resourcequota/admission_test.go

@@ -111,7 +111,7 @@ func createHandlerWithConfig(kubeClient kubernetes.Interface, informerFactory in
 
 	initializers := admission.PluginInitializers{
 		genericadmissioninitializer.New(kubeClient, nil, informerFactory, nil, nil, stopCh),
-		kubeapiserveradmission.NewPluginInitializer(nil, nil, quotaConfiguration, nil),
+		kubeapiserveradmission.NewPluginInitializer(nil, nil, quotaConfiguration),
 	}
 	initializers.Initialize(handler)
 

plugin/pkg/auth/authorizer/rbac/bootstrappolicy/controller_policy.go

@@ -441,6 +441,18 @@ func buildControllerRoles() ([]rbacv1.ClusterRole, []rbacv1.ClusterRoleBinding)
 			eventsRule(),
 		},
 	})
+	if utilfeature.DefaultFeatureGate.Enabled(genericfeatures.ValidatingAdmissionPolicy) {
+		addControllerRole(&controllerRoles, &controllerRoleBindings, rbacv1.ClusterRole{
+			ObjectMeta: metav1.ObjectMeta{Name: saRolePrefix + "validatingadmissionpolicy-status-controller"},
+			Rules: []rbacv1.PolicyRule{
+				rbacv1helpers.NewRule("get", "list", "watch").Groups(admissionRegistrationGroup).
+					Resources("validatingadmissionpolicies").RuleOrDie(),
+				rbacv1helpers.NewRule("get", "patch", "update").Groups(admissionRegistrationGroup).
+					Resources("validatingadmissionpolicies/status").RuleOrDie(),
+				eventsRule(),
+			},
+		})
+	}
 	if utilfeature.DefaultFeatureGate.Enabled(genericfeatures.StorageVersionAPI) &&
 		utilfeature.DefaultFeatureGate.Enabled(genericfeatures.APIServerIdentity) {
 		addControllerRole(&controllerRoles, &controllerRoleBindings, rbacv1.ClusterRole{

plugin/pkg/auth/authorizer/rbac/bootstrappolicy/policy.go

@@ -62,6 +62,7 @@ const (
 	networkingGroup            = "networking.k8s.io"
 	eventsGroup                = "events.k8s.io"
 	internalAPIServerGroup     = "internal.apiserver.k8s.io"
+	admissionRegistrationGroup = "admissionregistration.k8s.io"
 )
 
 func addDefaultMetadata(obj runtime.Object) {

staging/src/k8s.io/apiserver/pkg/admission/plugin/validatingadmissionpolicy/admission.go

@@ -24,7 +24,6 @@ import (
 
 	"k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apiserver/pkg/authorization/authorizer"
-	"k8s.io/apiserver/pkg/cel/openapi/resolver"
 	"k8s.io/apiserver/pkg/features"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/component-base/featuregate"
@@ -74,7 +73,6 @@ type celAdmissionPlugin struct {
 	dynamicClient   dynamic.Interface
 	stopCh          <-chan struct{}
 	authorizer      authorizer.Authorizer
-	schemaResolver  resolver.SchemaResolver
 }
 
 var _ initializer.WantsExternalKubeInformerFactory = &celAdmissionPlugin{}
@@ -83,7 +81,6 @@ var _ initializer.WantsRESTMapper = &celAdmissionPlugin{}
 var _ initializer.WantsDynamicClient = &celAdmissionPlugin{}
 var _ initializer.WantsDrainedNotification = &celAdmissionPlugin{}
 var _ initializer.WantsAuthorizer = &celAdmissionPlugin{}
-var _ initializer.WantsSchemaResolver = &celAdmissionPlugin{}
 var _ admission.InitializationValidator = &celAdmissionPlugin{}
 var _ admission.ValidationInterface = &celAdmissionPlugin{}
 
@@ -116,11 +113,6 @@ func (c *celAdmissionPlugin) SetDrainedNotification(stopCh <-chan struct{}) {
 func (c *celAdmissionPlugin) SetAuthorizer(authorizer authorizer.Authorizer) {
 	c.authorizer = authorizer
 }
-
-func (c *celAdmissionPlugin) SetSchemaResolver(resolver resolver.SchemaResolver) {
-	c.schemaResolver = resolver
-}
-
 func (c *celAdmissionPlugin) InspectFeatureGates(featureGates featuregate.FeatureGate) {
 	if featureGates.Enabled(features.ValidatingAdmissionPolicy) {
 		c.enabled = true
@@ -154,7 +146,7 @@ func (c *celAdmissionPlugin) ValidateInitialization() error {
 	if c.authorizer == nil {
 		return errors.New("missing authorizer")
 	}
-	c.evaluator = NewAdmissionController(c.informerFactory, c.client, c.restMapper, c.schemaResolver /* (optional) */, c.dynamicClient, c.authorizer)
+	c.evaluator = NewAdmissionController(c.informerFactory, c.client, c.restMapper, c.dynamicClient, c.authorizer)
 	if err := c.evaluator.ValidateInitialization(); err != nil {
 		return err
 	}

staging/src/k8s.io/apiserver/pkg/admission/plugin/validatingadmissionpolicy/controller.go

@@ -25,8 +25,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	"k8s.io/klog/v2"
-
 	"k8s.io/api/admissionregistration/v1alpha1"
 	k8serrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/meta"
@@ -44,12 +42,12 @@ import (
 	celconfig "k8s.io/apiserver/pkg/apis/cel"
 	"k8s.io/apiserver/pkg/authorization/authorizer"
 	"k8s.io/apiserver/pkg/cel/environment"
-	"k8s.io/apiserver/pkg/cel/openapi/resolver"
 	"k8s.io/apiserver/pkg/warning"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/tools/cache"
+	"k8s.io/klog/v2"
 )
 
 var _ CELPolicyEvaluator = &celAdmissionController{}
@@ -128,21 +126,15 @@ func NewAdmissionController(
 	informerFactory informers.SharedInformerFactory,
 	client kubernetes.Interface,
 	restMapper meta.RESTMapper,
-	schemaResolver resolver.SchemaResolver,
 	dynamicClient dynamic.Interface,
 	authz authorizer.Authorizer,
 ) CELPolicyEvaluator {
-	var typeChecker *TypeChecker
-	if schemaResolver != nil {
-		typeChecker = &TypeChecker{schemaResolver: schemaResolver, restMapper: restMapper}
-	}
 	return &celAdmissionController{
 		definitions: atomic.Value{},
 		policyController: newPolicyController(
 			restMapper,
 			client,
 			dynamicClient,
-			typeChecker,
 			cel.NewFilterCompiler(environment.MustBaseEnvSet(environment.DefaultCompatibilityVersion())),
 			NewMatcher(matching.NewMatcher(informerFactory.Core().V1().Namespaces().Lister(), client)),
 			generic.NewInformer[*v1alpha1.ValidatingAdmissionPolicy](

staging/src/k8s.io/apiserver/pkg/admission/plugin/validatingadmissionpolicy/controller_reconcile.go

@@ -27,10 +27,8 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	apiequality "k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/meta"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
-	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
 	celmetrics "k8s.io/apiserver/pkg/admission/cel"
 	"k8s.io/apiserver/pkg/admission/plugin/cel"
@@ -61,11 +59,6 @@ type policyController struct {
 
 	newValidator
 
-	// The TypeCheck checks the policy's expressions for type errors.
-	// Type of params is defined in policy.Spec.ParamsKind
-	// Types of object are calculated from policy.Spec.MatchingConstraints
-	typeChecker *TypeChecker
-
 	// Lock which protects:
 	//  - cachedPolicies
 	//  - paramCRDControllers
@@ -103,7 +96,6 @@ func newPolicyController(
 	restMapper meta.RESTMapper,
 	client kubernetes.Interface,
 	dynamicClient dynamic.Interface,
-	typeChecker *TypeChecker,
 	filterCompiler cel.FilterCompiler,
 	matcher Matcher,
 	policiesInformer generic.Informer[*v1alpha1.ValidatingAdmissionPolicy],
@@ -112,7 +104,6 @@ func newPolicyController(
 	res := &policyController{}
 	*res = policyController{
 		filterCompiler:        filterCompiler,
-		typeChecker:           typeChecker,
 		definitionInfo:        make(map[namespacedName]*definitionInfo),
 		bindingInfos:          make(map[namespacedName]*bindingInfo),
 		paramsCRDControllers:  make(map[v1alpha1.ParamKind]*paramInfo),
@@ -174,12 +165,6 @@ func (c *policyController) reconcilePolicyDefinition(namespace, name string, def
 	c.mutex.Lock()
 	defer c.mutex.Unlock()
 	err := c.reconcilePolicyDefinitionSpec(namespace, name, definition)
-	if err != nil {
-		return err
-	}
-	if c.typeChecker != nil {
-		err = c.reconcilePolicyStatus(namespace, name, definition)
-	}
 	return err
 }
 
@@ -438,30 +423,6 @@ func (c *policyController) reconcilePolicyBinding(namespace, name string, bindin
 	return nil
 }
 
-func (c *policyController) reconcilePolicyStatus(namespace, name string, definition *v1alpha1.ValidatingAdmissionPolicy) error {
-	if definition != nil && definition.Status.ObservedGeneration < definition.Generation {
-		st := c.calculatePolicyStatus(definition)
-		newDefinition := definition.DeepCopy()
-		newDefinition.Status = *st
-		_, err := c.client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().UpdateStatus(c.context, newDefinition, metav1.UpdateOptions{})
-		if err != nil {
-			// ignore error when the controller is not able to
-			// mutate the definition, and to avoid infinite requeue.
-			utilruntime.HandleError(err)
-		}
-	}
-	return nil
-}
-
-func (c *policyController) calculatePolicyStatus(definition *v1alpha1.ValidatingAdmissionPolicy) *v1alpha1.ValidatingAdmissionPolicyStatus {
-	expressionWarnings := c.typeChecker.Check(definition)
-	// modifying a deepcopy of the original status, preserving unrelated existing data
-	status := definition.Status.DeepCopy()
-	status.ObservedGeneration = definition.Generation
-	status.TypeChecking = &v1alpha1.TypeChecking{ExpressionWarnings: expressionWarnings}
-	return status
-}
-
 func (c *policyController) reconcileParams(namespace, name string, params runtime.Object) error {
 	// Do nothing.
 	// When we add informational type checking we will need to compile in the

staging/src/k8s.io/apiserver/pkg/admission/plugin/validatingadmissionpolicy/typechecking.go

@@ -44,8 +44,8 @@ import (
 const maxTypesToCheck = 10
 
 type TypeChecker struct {
-	schemaResolver resolver.SchemaResolver
+	SchemaResolver resolver.SchemaResolver
-	restMapper     meta.RESTMapper
+	RestMapper     meta.RESTMapper
 }
 
 // TypeCheckingContext holds information about the policy being type-checked.
@@ -196,7 +196,7 @@ func (c *TypeChecker) declType(gvk schema.GroupVersionKind) (*apiservercel.DeclT
 	if gvk.Empty() {
 		return nil, nil
 	}
-	s, err := c.schemaResolver.ResolveSchema(gvk)
+	s, err := c.SchemaResolver.ResolveSchema(gvk)
 	if err != nil {
 		return nil, err
 	}
@@ -266,7 +266,7 @@ func (c *TypeChecker) typesToCheck(p *v1alpha1.ValidatingAdmissionPolicy) []sche
 						Version:  version,
 						Resource: resource,
 					}
-					resolved, err := c.restMapper.KindsFor(gvr)
+					resolved, err := c.RestMapper.KindsFor(gvr)
 					if err != nil {
 						continue
 					}

staging/src/k8s.io/apiserver/pkg/admission/plugin/validatingadmissionpolicy/typechecking_test.go

@@ -435,8 +435,8 @@ func buildTypeChecker(schemaToReturn *spec.Schema) *TypeChecker {
 	restMapper.Add(must3(scheme.ObjectKinds(&appsv1.Deployment{}))[0], meta.RESTScopeRoot)
 
 	return &TypeChecker{
-		schemaResolver: &fakeSchemaResolver{schemaToReturn: schemaToReturn},
+		SchemaResolver: &fakeSchemaResolver{schemaToReturn: schemaToReturn},
-		restMapper:     restMapper,
+		RestMapper:     restMapper,
 	}
 }
 

staging/src/k8s.io/kube-controller-manager/config/v1alpha1/types.go

@@ -165,6 +165,9 @@ type KubeControllerManagerConfiguration struct {
 	// TTLAfterFinishedControllerConfiguration holds configuration for
 	// TTLAfterFinishedController related features.
 	TTLAfterFinishedController TTLAfterFinishedControllerConfiguration
+	// ValidatingAdmissionPolicyStatusControllerConfiguration holds configuration for
+	// ValidatingAdmissionPolicyStatusController related features.
+	ValidatingAdmissionPolicyStatusController ValidatingAdmissionPolicyStatusControllerConfiguration
 }
 
 // AttachDetachControllerConfiguration contains elements describing AttachDetachController.
@@ -481,3 +484,12 @@ type TTLAfterFinishedControllerConfiguration struct {
 	// allowed to sync concurrently.
 	ConcurrentTTLSyncs int32
 }
+
+// ValidatingAdmissionPolicyStatusControllerConfiguration contains elements describing ValidatingAdmissionPolicyStatusController.
+type ValidatingAdmissionPolicyStatusControllerConfiguration struct {
+	// ConcurrentPolicySyncs is the number of policy objects that are
+	// allowed to sync concurrently. Larger number = quicker type checking,
+	// but more CPU (and network) load.
+	// The default value is 5.
+	ConcurrentPolicySyncs int32
+}

staging/src/k8s.io/kube-controller-manager/config/v1alpha1/zz_generated.deepcopy.go

@@ -322,6 +322,7 @@ func (in *KubeControllerManagerConfiguration) DeepCopyInto(out *KubeControllerMa
 	out.SAController = in.SAController
 	out.ServiceController = in.ServiceController
 	out.TTLAfterFinishedController = in.TTLAfterFinishedController
+	out.ValidatingAdmissionPolicyStatusController = in.ValidatingAdmissionPolicyStatusController
 	return
 }
 
@@ -569,6 +570,22 @@ func (in *TTLAfterFinishedControllerConfiguration) DeepCopy() *TTLAfterFinishedC
 	return out
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *ValidatingAdmissionPolicyStatusControllerConfiguration) DeepCopyInto(out *ValidatingAdmissionPolicyStatusControllerConfiguration) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ValidatingAdmissionPolicyStatusControllerConfiguration.
+func (in *ValidatingAdmissionPolicyStatusControllerConfiguration) DeepCopy() *ValidatingAdmissionPolicyStatusControllerConfiguration {
+	if in == nil {
+		return nil
+	}
+	out := new(ValidatingAdmissionPolicyStatusControllerConfiguration)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *VolumeConfiguration) DeepCopyInto(out *VolumeConfiguration) {
 	*out = *in

test/e2e/apimachinery/validatingadmissionpolicy.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	"github.com/onsi/ginkgo/v2"
+	"github.com/onsi/gomega"
 
 	admissionregistrationv1 "k8s.io/api/admissionregistration/v1"
 	admissionregistrationv1alpha1 "k8s.io/api/admissionregistration/v1alpha1"
@@ -112,6 +113,81 @@ var _ = SIGDescribe("ValidatingAdmissionPolicy [Privileged:ClusterAdmin][Alpha][
 			framework.ExpectNoError(err, "create non-replicated ReplicaSet")
 		})
 	})
+
+	ginkgo.It("should type check validation expressions", func(ctx context.Context) {
+		var policy *admissionregistrationv1alpha1.ValidatingAdmissionPolicy
+		ginkgo.By("creating the policy with correct types", func() {
+			policy = newValidatingAdmissionPolicyBuilder(f.UniqueName+".correct-policy.example.com").
+				MatchUniqueNamespace(f.UniqueName).
+				StartResourceRule().
+				MatchResource([]string{"apps"}, []string{"v1"}, []string{"deployments"}).
+				EndResourceRule().
+				WithValidation(admissionregistrationv1alpha1.Validation{
+					Expression: "object.spec.replicas > 1",
+				}).
+				Build()
+			var err error
+			policy, err = client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Create(ctx, policy, metav1.CreateOptions{})
+			framework.ExpectNoError(err, "create policy")
+			ginkgo.DeferCleanup(func(ctx context.Context, name string) error {
+				return client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Delete(ctx, name, metav1.DeleteOptions{})
+			}, policy.Name)
+		})
+		ginkgo.By("waiting for the type check to finish without any warnings", func() {
+			err := wait.PollUntilContextCancel(ctx, 100*time.Millisecond, true, func(ctx context.Context) (done bool, err error) {
+				policy, err = client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Get(ctx, policy.Name, metav1.GetOptions{})
+				if err != nil {
+					return false, err
+				}
+				if policy.Status.TypeChecking != nil { // non-nil TypeChecking indicates its completion
+					return true, nil
+				}
+				return false, nil
+			})
+			framework.ExpectNoError(err, "wait for type checking")
+			gomega.Expect(policy.Status.TypeChecking.ExpressionWarnings).To(gomega.BeEmpty())
+		})
+		ginkgo.By("creating the policy with type confusion", func() {
+			policy = newValidatingAdmissionPolicyBuilder(f.UniqueName+".confused-policy.example.com").
+				MatchUniqueNamespace(f.UniqueName).
+				StartResourceRule().
+				MatchResource([]string{"apps"}, []string{"v1"}, []string{"deployments"}).
+				EndResourceRule().
+				WithValidation(admissionregistrationv1alpha1.Validation{
+					Expression:        "object.spec.replicas > '1'",                        // confusion: int > string
+					MessageExpression: "'wants replicas > 1, got ' + object.spec.replicas", // confusion: string + int
+				}).
+				Build()
+			var err error
+			policy, err = client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Create(ctx, policy, metav1.CreateOptions{})
+			framework.ExpectNoError(err, "create policy")
+			ginkgo.DeferCleanup(func(ctx context.Context, name string) error {
+				return client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Delete(ctx, name, metav1.DeleteOptions{})
+			}, policy.Name)
+		})
+		ginkgo.By("waiting for the type check to finish with warnings", func() {
+			err := wait.PollUntilContextCancel(ctx, 100*time.Millisecond, true, func(ctx context.Context) (done bool, err error) {
+				policy, err = client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Get(ctx, policy.Name, metav1.GetOptions{})
+				if err != nil {
+					return false, err
+				}
+				if policy.Status.TypeChecking != nil { // non-nil TypeChecking indicates its completion
+					return true, nil
+				}
+				return false, nil
+			})
+			framework.ExpectNoError(err, "wait for type checking")
+
+			// assert it to contain 2 warnings, first for expression and second for messageExpression
+			gomega.Expect(policy.Status.TypeChecking.ExpressionWarnings).To(gomega.HaveLen(2))
+			warning := policy.Status.TypeChecking.ExpressionWarnings[0]
+			gomega.Expect(warning.FieldRef).To(gomega.Equal("spec.validations[0].expression"))
+			gomega.Expect(warning.Warning).To(gomega.ContainSubstring("found no matching overload for '_>_' applied to '(int, string)'"))
+			warning = policy.Status.TypeChecking.ExpressionWarnings[1]
+			gomega.Expect(warning.FieldRef).To(gomega.Equal("spec.validations[0].messageExpression"))
+			gomega.Expect(warning.Warning).To(gomega.ContainSubstring("found no matching overload for '_+_' applied to '(string, int)'"))
+		})
+	})
 })
 
 func createBinding(bindingName string, uniqueLabel string, policyName string) *admissionregistrationv1alpha1.ValidatingAdmissionPolicyBinding {

test/integration/apiserver/cel/validatingadmissionpolicy_test.go

@@ -2622,26 +2622,6 @@ func withPolicyExistsLabels(labels []string, policy *admissionregistrationv1alph
 	return policy
 }
 
-func withGVRMatch(groups []string, versions []string, resources []string, policy *admissionregistrationv1alpha1.ValidatingAdmissionPolicy) *admissionregistrationv1alpha1.ValidatingAdmissionPolicy {
-	policy.Spec.MatchConstraints = &admissionregistrationv1alpha1.MatchResources{
-		ResourceRules: []admissionregistrationv1alpha1.NamedRuleWithOperations{
-			{
-				RuleWithOperations: admissionregistrationv1alpha1.RuleWithOperations{
-					Operations: []admissionregistrationv1.OperationType{
-						"*",
-					},
-					Rule: admissionregistrationv1.Rule{
-						APIGroups:   groups,
-						APIVersions: versions,
-						Resources:   resources,
-					},
-				},
-			},
-		},
-	}
-	return policy
-}
-
 func withValidations(validations []admissionregistrationv1alpha1.Validation, policy *admissionregistrationv1alpha1.ValidatingAdmissionPolicy) *admissionregistrationv1alpha1.ValidatingAdmissionPolicy {
 	policy.Spec.Validations = validations
 	return policy
@@ -2917,117 +2897,6 @@ rules:
 `
 )
 
-func TestValidatingAdmissionPolicyTypeChecking(t *testing.T) {
-	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, genericfeatures.ValidatingAdmissionPolicy, true)()
-	server, err := apiservertesting.StartTestServer(t, nil, []string{
-		"--enable-admission-plugins", "ValidatingAdmissionPolicy",
-	}, framework.SharedEtcd())
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer server.TearDownFn()
-
-	config := server.ClientConfig
-
-	client, err := clientset.NewForConfig(config)
-	if err != nil {
-		t.Fatal(err)
-	}
-	for _, tc := range []struct {
-		name           string
-		policy         *admissionregistrationv1alpha1.ValidatingAdmissionPolicy
-		assertFieldRef func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) // warning.fieldRef
-		assertWarnings func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) // warning.warning
-	}{
-		{
-			name: "deployment with correct expression",
-			policy: withGVRMatch([]string{"apps"}, []string{"v1"}, []string{"deployments"}, withValidations([]admissionregistrationv1alpha1.Validation{
-				{
-					Expression: "object.spec.replicas > 1",
-				},
-			}, makePolicy("replicated-deployment"))),
-			assertFieldRef: toHasLengthOf(0),
-			assertWarnings: toHasLengthOf(0),
-		},
-		{
-			name: "deployment with type confusion",
-			policy: withGVRMatch([]string{"apps"}, []string{"v1"}, []string{"deployments"}, withValidations([]admissionregistrationv1alpha1.Validation{
-				{
-					Expression: "object.spec.replicas < 100", // this one passes
-				},
-				{
-					Expression: "object.spec.replicas > '1'", // '1' should be int
-				},
-			}, makePolicy("confused-deployment"))),
-			assertFieldRef: toBe("spec.validations[1].expression"),
-			assertWarnings: toHasSubstring(`found no matching overload for '_>_' applied to '(int, string)'`),
-		},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
-			defer cancel()
-			policy, err := client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Create(ctx, tc.policy, metav1.CreateOptions{})
-			if err != nil {
-				t.Fatal(err)
-			}
-			defer client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Delete(context.Background(), policy.Name, metav1.DeleteOptions{})
-			err = wait.PollImmediateWithContext(ctx, time.Second, time.Minute, func(ctx context.Context) (done bool, err error) {
-				name := policy.Name
-				// wait until the typeChecking is set, which means the type checking
-				// is complete.
-				updated, err := client.AdmissionregistrationV1alpha1().ValidatingAdmissionPolicies().Get(ctx, name, metav1.GetOptions{})
-				if err != nil {
-					return false, err
-				}
-				if updated.Status.TypeChecking != nil {
-					policy = updated
-					return true, nil
-				}
-				return false, nil
-			})
-			if err != nil {
-				t.Fatal(err)
-			}
-			tc.assertFieldRef(policy.Status.TypeChecking.ExpressionWarnings, t)
-			tc.assertWarnings(policy.Status.TypeChecking.ExpressionWarnings, t)
-		})
-	}
-}
-
-func toBe(expected ...string) func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
-	return func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
-		if len(expected) != len(warnings) {
-			t.Fatalf("mismatched length, expect %d, got %d", len(expected), len(warnings))
-		}
-		for i := range expected {
-			if expected[i] != warnings[i].FieldRef {
-				t.Errorf("expected %q but got %q", expected[i], warnings[i].FieldRef)
-			}
-		}
-	}
-}
-
-func toHasSubstring(substrings ...string) func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
-	return func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
-		if len(substrings) != len(warnings) {
-			t.Fatalf("mismatched length, expect %d, got %d", len(substrings), len(warnings))
-		}
-		for i := range substrings {
-			if !strings.Contains(warnings[i].Warning, substrings[i]) {
-				t.Errorf("missing expected substring %q in %v", substrings[i], warnings[i])
-			}
-		}
-	}
-}
-
-func toHasLengthOf(n int) func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
-	return func(warnings []admissionregistrationv1alpha1.ExpressionWarning, t *testing.T) {
-		if n != len(warnings) {
-			t.Fatalf("mismatched length, expect %d, got %d", n, len(warnings))
-		}
-	}
-}
-
 func TestAuthorizationDecisionCaching(t *testing.T) {
 	for _, tc := range []struct {
 		name        string