Merge pull request #88607 from caesarxuchao/add-storage-version-api

Add the storage version API

build/kazel_generated.bzl

@@ -86,6 +86,7 @@ tags_values_pkgs = {"openapi-gen": {
         "staging/src/k8s.io/apimachinery/pkg/runtime",
         "staging/src/k8s.io/apimachinery/pkg/util/intstr",
         "staging/src/k8s.io/apimachinery/pkg/version",
+        "staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1",
         "staging/src/k8s.io/apiserver/pkg/apis/audit/v1",
         "staging/src/k8s.io/apiserver/pkg/apis/audit/v1alpha1",
         "staging/src/k8s.io/apiserver/pkg/apis/audit/v1beta1",
@@ -168,6 +169,7 @@ tags_pkgs_values = {"openapi-gen": {
     "staging/src/k8s.io/apimachinery/pkg/runtime": ["true"],
     "staging/src/k8s.io/apimachinery/pkg/util/intstr": ["true"],
     "staging/src/k8s.io/apimachinery/pkg/version": ["true"],
+    "staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1": ["true"],
     "staging/src/k8s.io/apiserver/pkg/apis/audit/v1": ["true"],
     "staging/src/k8s.io/apiserver/pkg/apis/audit/v1alpha1": ["true"],
     "staging/src/k8s.io/apiserver/pkg/apis/audit/v1beta1": ["true"],

hack/.golint_failures

@@ -309,6 +309,8 @@ staging/src/k8s.io/apiserver/pkg/apis/apiserver
 staging/src/k8s.io/apiserver/pkg/apis/apiserver/v1
 staging/src/k8s.io/apiserver/pkg/apis/apiserver/v1alpha1
 staging/src/k8s.io/apiserver/pkg/apis/apiserver/v1beta1
+staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal
+staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1
 staging/src/k8s.io/apiserver/pkg/apis/audit
 staging/src/k8s.io/apiserver/pkg/apis/audit/v1
 staging/src/k8s.io/apiserver/pkg/apis/audit/v1alpha1

staging/src/k8s.io/apiserver/BUILD

@@ -11,6 +11,7 @@ filegroup(
         ":package-srcs",
         "//staging/src/k8s.io/apiserver/pkg/admission:all-srcs",
         "//staging/src/k8s.io/apiserver/pkg/apis/apiserver:all-srcs",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal:all-srcs",
         "//staging/src/k8s.io/apiserver/pkg/apis/audit:all-srcs",
         "//staging/src/k8s.io/apiserver/pkg/apis/config:all-srcs",
         "//staging/src/k8s.io/apiserver/pkg/apis/example:all-srcs",

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/BUILD

@@ -0,0 +1,42 @@
+package(default_visibility = ["//visibility:public"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_library",
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "doc.go",
+        "register.go",
+        "types.go",
+        "zz_generated.deepcopy.go",
+    ],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/apis/apiserverinternal",
+    importpath = "k8s.io/apiserver/pkg/apis/apiserverinternal",
+    deps = [
+        "//staging/src/k8s.io/apimachinery/pkg/apis/meta/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",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [
+        ":package-srcs",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/fuzzer:all-srcs",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/install:all-srcs",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1:all-srcs",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/validation:all-srcs",
+    ],
+    tags = ["automanaged"],
+)

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/doc.go

@@ -0,0 +1,22 @@
+/*
+Copyright 2019 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
+// +groupName=internal.apiserver.k8s.io
+
+// Package apiserverinternal contains the "internal" version of the API used by
+// the apiservers themselves.
+package apiserverinternal // import "k8s.io/apiserver/pkg/apis/apiserverinternal"

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/fuzzer/BUILD

@@ -0,0 +1,24 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["fuzzer.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/apis/apiserverinternal/fuzzer",
+    importpath = "k8s.io/apiserver/pkg/apis/apiserverinternal/fuzzer",
+    visibility = ["//visibility:public"],
+    deps = ["//staging/src/k8s.io/apimachinery/pkg/runtime/serializer:go_default_library"],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/fuzzer/fuzzer.go

@@ -0,0 +1,26 @@
+/*
+Copyright 2019 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 fuzzer
+
+import (
+	runtimeserializer "k8s.io/apimachinery/pkg/runtime/serializer"
+)
+
+// Funcs returns the fuzzer functions for the apiserverinternal api group.
+func Funcs(codecs runtimeserializer.CodecFactory) []interface{} {
+	return []interface{}{}
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/install/BUILD

@@ -0,0 +1,43 @@
+package(default_visibility = ["//visibility:public"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_library",
+    "go_test",
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = ["install.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/apis/apiserverinternal/install",
+    importpath = "k8s.io/apiserver/pkg/apis/apiserverinternal/install",
+    deps = [
+        "//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/apiserver/pkg/apis/apiserverinternal:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["roundtrip_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//staging/src/k8s.io/apimachinery/pkg/api/apitesting/roundtrip:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/fuzzer:go_default_library",
+    ],
+)

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/install/install.go

@@ -0,0 +1,33 @@
+/*
+Copyright 2019 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 install installs the experimental API group, making it available as
+// an option to all of the API encoding/decoding machinery.
+package install
+
+import (
+	"k8s.io/apimachinery/pkg/runtime"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apiserver/pkg/apis/apiserverinternal"
+	"k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1"
+)
+
+// Install registers the API group and adds types to a scheme
+func Install(scheme *runtime.Scheme) {
+	utilruntime.Must(apiserverinternal.AddToScheme(scheme))
+	utilruntime.Must(v1alpha1.AddToScheme(scheme))
+	utilruntime.Must(scheme.SetVersionPriority(v1alpha1.SchemeGroupVersion))
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/install/roundtrip_test.go

@@ -0,0 +1,29 @@
+/*
+Copyright 2019 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 install
+
+import (
+	"testing"
+
+	"k8s.io/apimachinery/pkg/api/apitesting/roundtrip"
+	"k8s.io/apiserver/pkg/apis/apiserverinternal/fuzzer"
+)
+
+func TestRoundTrip(t *testing.T) {
+	roundtrip.RoundTripTestForAPIGroup(t, Install, fuzzer.Funcs)
+	roundtrip.RoundTripProtobufTestForAPIGroup(t, Install, fuzzer.Funcs)
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/register.go

@@ -0,0 +1,53 @@
+/*
+Copyright 2019 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 apiserverinternal
+
+import (
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// GroupName is the group name use in this package
+const GroupName = "internal.apiserver.k8s.io"
+
+// SchemeGroupVersion is group version used to register these objects
+var SchemeGroupVersion = schema.GroupVersion{Group: GroupName, Version: runtime.APIVersionInternal}
+
+// Kind takes an unqualified kind and returns a Group qualified GroupKind
+func Kind(kind string) schema.GroupKind {
+	return SchemeGroupVersion.WithKind(kind).GroupKind()
+}
+
+// Resource takes an unqualified resource and returns a Group qualified GroupResource
+func Resource(resource string) schema.GroupResource {
+	return SchemeGroupVersion.WithResource(resource).GroupResource()
+}
+
+var (
+	// SchemeBuilder is the scheme builder with scheme init functions to run for this API package.
+	SchemeBuilder = runtime.NewSchemeBuilder(addKnownTypes)
+	// AddToScheme is a global function that registers this API group & version to a scheme
+	AddToScheme = SchemeBuilder.AddToScheme
+)
+
+func addKnownTypes(scheme *runtime.Scheme) error {
+	scheme.AddKnownTypes(SchemeGroupVersion,
+		&StorageVersion{},
+		&StorageVersionList{},
+	)
+	return nil
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/types.go

@@ -0,0 +1,120 @@
+/*
+Copyright 2019 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 apiserverinternal
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+
+//  Storage version of a specific resource.
+type StorageVersion struct {
+	metav1.TypeMeta
+	// The name is <group>.<resource>.
+	metav1.ObjectMeta
+
+	// Spec is an empty spec. It is here to comply with Kubernetes API style.
+	Spec StorageVersionSpec
+
+	// API server instances report the version they can decode and the version they
+	// encode objects to when persisting objects in the backend.
+	Status StorageVersionStatus
+}
+
+// StorageVersionSpec is an empty spec.
+type StorageVersionSpec struct{}
+
+// API server instances report the versions they can decode and the version they
+// encode objects to when persisting objects in the backend.
+type StorageVersionStatus struct {
+	// The reported versions per API server instance.
+	// +optional
+	StorageVersions []ServerStorageVersion
+	// If all API server instances agree on the same encoding storage version,
+	// then this field is set to that version. Otherwise this field is left empty.
+	// API servers should finish updating its storageVersionStatus entry before
+	// serving write operations, so that this field will be in sync with the reality.
+	// +optional
+	CommonEncodingVersion *string
+
+	// The latest available observations of the storageVersion's state.
+	// +optional
+	Conditions []StorageVersionCondition
+}
+
+// An API server instance reports the version it can decode and the version it
+// encodes objects to when persisting objects in the backend.
+type ServerStorageVersion struct {
+	// The ID of the reporting API server.
+	APIServerID string
+
+	// The API server encodes the object to this version when persisting it in
+	// the backend (e.g., etcd).
+	EncodingVersion string
+
+	// The API server can decode objects encoded in these versions.
+	// The encodingVersion must be included in the decodableVersions.
+	DecodableVersions []string
+}
+
+type StorageVersionConditionType string
+
+const (
+	// Indicates that encoding storage versions reported by all servers are equal.
+	AllEncodingVersionsEqual StorageVersionConditionType = "AllEncodingVersionsEqual"
+)
+
+type ConditionStatus string
+
+const (
+	ConditionTrue    ConditionStatus = "True"
+	ConditionFalse   ConditionStatus = "False"
+	ConditionUnknown ConditionStatus = "Unknown"
+)
+
+// Describes the state of the storageVersion at a certain point.
+type StorageVersionCondition struct {
+	// Type of the condition.
+	// +optional
+	Type StorageVersionConditionType
+	// Status of the condition, one of True, False, Unknown.
+	// +required
+	Status ConditionStatus
+	// If set, this represents the .metadata.generation that the condition was set based upon.
+	// +optional
+	ObservedGeneration int64
+	// Last time the condition transitioned from one status to another.
+	// +required
+	LastTransitionTime metav1.Time
+	// The reason for the condition's last transition.
+	// +required
+	Reason string
+	// A human readable message indicating details about the transition.
+	// +required
+	Message string
+}
+
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+
+// A list of StorageVersions.
+type StorageVersionList struct {
+	metav1.TypeMeta
+	// +optional
+	metav1.ListMeta
+	Items []StorageVersion
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1/BUILD

@@ -0,0 +1,39 @@
+package(default_visibility = ["//visibility:public"])
+
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "doc.go",
+        "generated.pb.go",
+        "register.go",
+        "types.go",
+        "zz_generated.conversion.go",
+        "zz_generated.deepcopy.go",
+        "zz_generated.defaults.go",
+    ],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1",
+    importpath = "k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1",
+    deps = [
+        "//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/runtime/schema:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal:go_default_library",
+        "//vendor/github.com/gogo/protobuf/proto:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+)

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1/doc.go

@@ -0,0 +1,27 @@
+/*
+Copyright 2019 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:protobuf-gen=package
+// +k8s:conversion-gen=k8s.io/apiserver/pkg/apis/apiserverinternal
+// +k8s:openapi-gen=true
+// +k8s:defaulter-gen=TypeMeta
+
+// +groupName=internal.apiserver.k8s.io
+
+// Package v1alpha1 contains the v1alpha1 version of the API used by the
+// apiservers themselves.
+package v1alpha1 // import "k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1"

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1/generated.proto

@@ -0,0 +1,121 @@
+/*
+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.
+*/
+
+
+// This file was autogenerated by go-to-protobuf. Do not edit it manually!
+
+syntax = 'proto2';
+
+package k8s.io.apiserver.pkg.apis.apiserverinternal.v1alpha1;
+
+import "k8s.io/apimachinery/pkg/apis/meta/v1/generated.proto";
+import "k8s.io/apimachinery/pkg/runtime/generated.proto";
+import "k8s.io/apimachinery/pkg/runtime/schema/generated.proto";
+
+// Package-wide variables from generator "generated".
+option go_package = "v1alpha1";
+
+// An API server instance reports the version it can decode and the version it
+// encodes objects to when persisting objects in the backend.
+message ServerStorageVersion {
+  // The ID of the reporting API server.
+  optional string apiServerID = 1;
+
+  // The API server encodes the object to this version when persisting it in
+  // the backend (e.g., etcd).
+  optional string encodingVersion = 2;
+
+  // The API server can decode objects encoded in these versions.
+  // The encodingVersion must be included in the decodableVersions.
+  // +listType=set
+  repeated string decodableVersions = 3;
+}
+
+//  Storage version of a specific resource.
+message StorageVersion {
+  // The name is <group>.<resource>.
+  optional k8s.io.apimachinery.pkg.apis.meta.v1.ObjectMeta metadata = 1;
+
+  // Spec is an empty spec. It is here to comply with Kubernetes API style.
+  optional StorageVersionSpec spec = 2;
+
+  // API server instances report the version they can decode and the version they
+  // encode objects to when persisting objects in the backend.
+  optional StorageVersionStatus status = 3;
+}
+
+// Describes the state of the storageVersion at a certain point.
+message StorageVersionCondition {
+  // Type of the condition.
+  // +required
+  optional string type = 1;
+
+  // Status of the condition, one of True, False, Unknown.
+  // +required
+  optional string status = 2;
+
+  // If set, this represents the .metadata.generation that the condition was set based upon.
+  // +optional
+  optional int64 observedGeneration = 3;
+
+  // Last time the condition transitioned from one status to another.
+  // +required
+  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time lastTransitionTime = 4;
+
+  // The reason for the condition's last transition.
+  // +required
+  optional string reason = 5;
+
+  // A human readable message indicating details about the transition.
+  // +required
+  optional string message = 6;
+}
+
+// A list of StorageVersions.
+message StorageVersionList {
+  // +optional
+  optional k8s.io.apimachinery.pkg.apis.meta.v1.ListMeta metadata = 1;
+
+  repeated StorageVersion items = 2;
+}
+
+// StorageVersionSpec is an empty spec.
+message StorageVersionSpec {
+}
+
+// API server instances report the versions they can decode and the version they
+// encode objects to when persisting objects in the backend.
+message StorageVersionStatus {
+  // The reported versions per API server instance.
+  // +optional
+  // +listType=map
+  // +listMapKey=apiserverID
+  repeated ServerStorageVersion storageVersions = 1;
+
+  // If all API server instances agree on the same encoding storage version,
+  // then this field is set to that version. Otherwise this field is left empty.
+  // API servers should finish updating its storageVersionStatus entry before
+  // serving write operations, so that this field will be in sync with the reality.
+  // +optional
+  optional string commonEncodingVersion = 2;
+
+  // The latest available observations of the storageVersion's state.
+  // +optional
+  // +listType=map
+  // +listMapKey=type
+  repeated StorageVersionCondition conditions = 3;
+}
+

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1/register.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2019 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 (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// GroupName is the group name use in this package
+const GroupName = "internal.apiserver.k8s.io"
+
+// SchemeGroupVersion is group version used to register these objects
+var SchemeGroupVersion = schema.GroupVersion{Group: GroupName, Version: "v1alpha1"}
+
+// Resource takes an unqualified resource and returns a Group qualified GroupResource
+func Resource(resource string) schema.GroupResource {
+	return SchemeGroupVersion.WithResource(resource).GroupResource()
+}
+
+var (
+	SchemeBuilder      runtime.SchemeBuilder
+	localSchemeBuilder = &SchemeBuilder
+	AddToScheme        = localSchemeBuilder.AddToScheme
+)
+
+func init() {
+	// We only register manually written functions here. The registration of the
+	// generated functions takes place in the generated files. The separation
+	// makes the code compile even when the generated files are missing.
+	localSchemeBuilder.Register(addKnownTypes)
+}
+
+func addKnownTypes(scheme *runtime.Scheme) error {
+	scheme.AddKnownTypes(SchemeGroupVersion,
+		&StorageVersion{},
+		&StorageVersionList{},
+	)
+	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
+	return nil
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1/types.go

@@ -0,0 +1,127 @@
+/*
+Copyright 2019 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 (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// +genclient
+// +genclient:nonNamespaced
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+
+//  Storage version of a specific resource.
+type StorageVersion struct {
+	metav1.TypeMeta `json:",inline"`
+	// The name is <group>.<resource>.
+	metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`
+
+	// Spec is an empty spec. It is here to comply with Kubernetes API style.
+	Spec StorageVersionSpec `json:"spec" protobuf:"bytes,2,opt,name=spec"`
+
+	// API server instances report the version they can decode and the version they
+	// encode objects to when persisting objects in the backend.
+	Status StorageVersionStatus `json:"status" protobuf:"bytes,3,opt,name=status"`
+}
+
+// StorageVersionSpec is an empty spec.
+type StorageVersionSpec struct{}
+
+// API server instances report the versions they can decode and the version they
+// encode objects to when persisting objects in the backend.
+type StorageVersionStatus struct {
+	// The reported versions per API server instance.
+	// +optional
+	// +listType=map
+	// +listMapKey=apiserverID
+	StorageVersions []ServerStorageVersion `json:"storageVersions,omitempty" protobuf:"bytes,1,opt,name=storageVersions"`
+	// If all API server instances agree on the same encoding storage version,
+	// then this field is set to that version. Otherwise this field is left empty.
+	// API servers should finish updating its storageVersionStatus entry before
+	// serving write operations, so that this field will be in sync with the reality.
+	// +optional
+	CommonEncodingVersion *string `json:"commonEncodingVersion,omitempty" protobuf:"bytes,2,opt,name=commonEncodingVersion"`
+
+	// The latest available observations of the storageVersion's state.
+	// +optional
+	// +listType=map
+	// +listMapKey=type
+	Conditions []StorageVersionCondition `json:"conditions,omitempty" protobuf:"bytes,3,opt,name=conditions"`
+}
+
+// An API server instance reports the version it can decode and the version it
+// encodes objects to when persisting objects in the backend.
+type ServerStorageVersion struct {
+	// The ID of the reporting API server.
+	APIServerID string `json:"apiServerID,omitempty" protobuf:"bytes,1,opt,name=apiServerID"`
+
+	// The API server encodes the object to this version when persisting it in
+	// the backend (e.g., etcd).
+	EncodingVersion string `json:"encodingVersion,omitempty" protobuf:"bytes,2,opt,name=encodingVersion"`
+
+	// The API server can decode objects encoded in these versions.
+	// The encodingVersion must be included in the decodableVersions.
+	// +listType=set
+	DecodableVersions []string `json:"decodableVersions,omitempty" protobuf:"bytes,3,opt,name=decodableVersions"`
+}
+
+type StorageVersionConditionType string
+
+const (
+	// Indicates that encoding storage versions reported by all servers are equal.
+	AllEncodingVersionsEqual StorageVersionConditionType = "AllEncodingVersionsEqual"
+)
+
+type ConditionStatus string
+
+const (
+	ConditionTrue    ConditionStatus = "True"
+	ConditionFalse   ConditionStatus = "False"
+	ConditionUnknown ConditionStatus = "Unknown"
+)
+
+// Describes the state of the storageVersion at a certain point.
+type StorageVersionCondition struct {
+	// Type of the condition.
+	// +required
+	Type StorageVersionConditionType `json:"type" protobuf:"bytes,1,opt,name=type"`
+	// Status of the condition, one of True, False, Unknown.
+	// +required
+	Status ConditionStatus `json:"status" protobuf:"bytes,2,opt,name=status"`
+	// If set, this represents the .metadata.generation that the condition was set based upon.
+	// +optional
+	ObservedGeneration int64 `json:"observedGeneration,omitempty" protobuf:"varint,3,opt,name=observedGeneration"`
+	// Last time the condition transitioned from one status to another.
+	// +required
+	LastTransitionTime metav1.Time `json:"lastTransitionTime,omitempty" protobuf:"bytes,4,opt,name=lastTransitionTime"`
+	// The reason for the condition's last transition.
+	// +required
+	Reason string `json:"reason" protobuf:"bytes,5,opt,name=reason"`
+	// A human readable message indicating details about the transition.
+	// +required
+	Message string `json:"message,omitempty" protobuf:"bytes,6,opt,name=message"`
+}
+
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+
+// A list of StorageVersions.
+type StorageVersionList struct {
+	metav1.TypeMeta `json:",inline"`
+	// +optional
+	metav1.ListMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`
+	Items           []StorageVersion `json:"items" protobuf:"bytes,2,rep,name=items"`
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1/zz_generated.conversion.go

@@ -0,0 +1,249 @@
+// +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 (
+	unsafe "unsafe"
+
+	conversion "k8s.io/apimachinery/pkg/conversion"
+	runtime "k8s.io/apimachinery/pkg/runtime"
+	apiserverinternal "k8s.io/apiserver/pkg/apis/apiserverinternal"
+)
+
+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((*ServerStorageVersion)(nil), (*apiserverinternal.ServerStorageVersion)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_ServerStorageVersion_To_apiserverinternal_ServerStorageVersion(a.(*ServerStorageVersion), b.(*apiserverinternal.ServerStorageVersion), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserverinternal.ServerStorageVersion)(nil), (*ServerStorageVersion)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserverinternal_ServerStorageVersion_To_v1alpha1_ServerStorageVersion(a.(*apiserverinternal.ServerStorageVersion), b.(*ServerStorageVersion), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*StorageVersion)(nil), (*apiserverinternal.StorageVersion)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_StorageVersion_To_apiserverinternal_StorageVersion(a.(*StorageVersion), b.(*apiserverinternal.StorageVersion), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserverinternal.StorageVersion)(nil), (*StorageVersion)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserverinternal_StorageVersion_To_v1alpha1_StorageVersion(a.(*apiserverinternal.StorageVersion), b.(*StorageVersion), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*StorageVersionCondition)(nil), (*apiserverinternal.StorageVersionCondition)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_StorageVersionCondition_To_apiserverinternal_StorageVersionCondition(a.(*StorageVersionCondition), b.(*apiserverinternal.StorageVersionCondition), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserverinternal.StorageVersionCondition)(nil), (*StorageVersionCondition)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserverinternal_StorageVersionCondition_To_v1alpha1_StorageVersionCondition(a.(*apiserverinternal.StorageVersionCondition), b.(*StorageVersionCondition), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*StorageVersionList)(nil), (*apiserverinternal.StorageVersionList)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_StorageVersionList_To_apiserverinternal_StorageVersionList(a.(*StorageVersionList), b.(*apiserverinternal.StorageVersionList), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserverinternal.StorageVersionList)(nil), (*StorageVersionList)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserverinternal_StorageVersionList_To_v1alpha1_StorageVersionList(a.(*apiserverinternal.StorageVersionList), b.(*StorageVersionList), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*StorageVersionSpec)(nil), (*apiserverinternal.StorageVersionSpec)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_StorageVersionSpec_To_apiserverinternal_StorageVersionSpec(a.(*StorageVersionSpec), b.(*apiserverinternal.StorageVersionSpec), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserverinternal.StorageVersionSpec)(nil), (*StorageVersionSpec)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserverinternal_StorageVersionSpec_To_v1alpha1_StorageVersionSpec(a.(*apiserverinternal.StorageVersionSpec), b.(*StorageVersionSpec), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*StorageVersionStatus)(nil), (*apiserverinternal.StorageVersionStatus)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_StorageVersionStatus_To_apiserverinternal_StorageVersionStatus(a.(*StorageVersionStatus), b.(*apiserverinternal.StorageVersionStatus), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserverinternal.StorageVersionStatus)(nil), (*StorageVersionStatus)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserverinternal_StorageVersionStatus_To_v1alpha1_StorageVersionStatus(a.(*apiserverinternal.StorageVersionStatus), b.(*StorageVersionStatus), scope)
+	}); err != nil {
+		return err
+	}
+	return nil
+}
+
+func autoConvert_v1alpha1_ServerStorageVersion_To_apiserverinternal_ServerStorageVersion(in *ServerStorageVersion, out *apiserverinternal.ServerStorageVersion, s conversion.Scope) error {
+	out.APIServerID = in.APIServerID
+	out.EncodingVersion = in.EncodingVersion
+	out.DecodableVersions = *(*[]string)(unsafe.Pointer(&in.DecodableVersions))
+	return nil
+}
+
+// Convert_v1alpha1_ServerStorageVersion_To_apiserverinternal_ServerStorageVersion is an autogenerated conversion function.
+func Convert_v1alpha1_ServerStorageVersion_To_apiserverinternal_ServerStorageVersion(in *ServerStorageVersion, out *apiserverinternal.ServerStorageVersion, s conversion.Scope) error {
+	return autoConvert_v1alpha1_ServerStorageVersion_To_apiserverinternal_ServerStorageVersion(in, out, s)
+}
+
+func autoConvert_apiserverinternal_ServerStorageVersion_To_v1alpha1_ServerStorageVersion(in *apiserverinternal.ServerStorageVersion, out *ServerStorageVersion, s conversion.Scope) error {
+	out.APIServerID = in.APIServerID
+	out.EncodingVersion = in.EncodingVersion
+	out.DecodableVersions = *(*[]string)(unsafe.Pointer(&in.DecodableVersions))
+	return nil
+}
+
+// Convert_apiserverinternal_ServerStorageVersion_To_v1alpha1_ServerStorageVersion is an autogenerated conversion function.
+func Convert_apiserverinternal_ServerStorageVersion_To_v1alpha1_ServerStorageVersion(in *apiserverinternal.ServerStorageVersion, out *ServerStorageVersion, s conversion.Scope) error {
+	return autoConvert_apiserverinternal_ServerStorageVersion_To_v1alpha1_ServerStorageVersion(in, out, s)
+}
+
+func autoConvert_v1alpha1_StorageVersion_To_apiserverinternal_StorageVersion(in *StorageVersion, out *apiserverinternal.StorageVersion, s conversion.Scope) error {
+	out.ObjectMeta = in.ObjectMeta
+	if err := Convert_v1alpha1_StorageVersionSpec_To_apiserverinternal_StorageVersionSpec(&in.Spec, &out.Spec, s); err != nil {
+		return err
+	}
+	if err := Convert_v1alpha1_StorageVersionStatus_To_apiserverinternal_StorageVersionStatus(&in.Status, &out.Status, s); err != nil {
+		return err
+	}
+	return nil
+}
+
+// Convert_v1alpha1_StorageVersion_To_apiserverinternal_StorageVersion is an autogenerated conversion function.
+func Convert_v1alpha1_StorageVersion_To_apiserverinternal_StorageVersion(in *StorageVersion, out *apiserverinternal.StorageVersion, s conversion.Scope) error {
+	return autoConvert_v1alpha1_StorageVersion_To_apiserverinternal_StorageVersion(in, out, s)
+}
+
+func autoConvert_apiserverinternal_StorageVersion_To_v1alpha1_StorageVersion(in *apiserverinternal.StorageVersion, out *StorageVersion, s conversion.Scope) error {
+	out.ObjectMeta = in.ObjectMeta
+	if err := Convert_apiserverinternal_StorageVersionSpec_To_v1alpha1_StorageVersionSpec(&in.Spec, &out.Spec, s); err != nil {
+		return err
+	}
+	if err := Convert_apiserverinternal_StorageVersionStatus_To_v1alpha1_StorageVersionStatus(&in.Status, &out.Status, s); err != nil {
+		return err
+	}
+	return nil
+}
+
+// Convert_apiserverinternal_StorageVersion_To_v1alpha1_StorageVersion is an autogenerated conversion function.
+func Convert_apiserverinternal_StorageVersion_To_v1alpha1_StorageVersion(in *apiserverinternal.StorageVersion, out *StorageVersion, s conversion.Scope) error {
+	return autoConvert_apiserverinternal_StorageVersion_To_v1alpha1_StorageVersion(in, out, s)
+}
+
+func autoConvert_v1alpha1_StorageVersionCondition_To_apiserverinternal_StorageVersionCondition(in *StorageVersionCondition, out *apiserverinternal.StorageVersionCondition, s conversion.Scope) error {
+	out.Type = apiserverinternal.StorageVersionConditionType(in.Type)
+	out.Status = apiserverinternal.ConditionStatus(in.Status)
+	out.ObservedGeneration = in.ObservedGeneration
+	out.LastTransitionTime = in.LastTransitionTime
+	out.Reason = in.Reason
+	out.Message = in.Message
+	return nil
+}
+
+// Convert_v1alpha1_StorageVersionCondition_To_apiserverinternal_StorageVersionCondition is an autogenerated conversion function.
+func Convert_v1alpha1_StorageVersionCondition_To_apiserverinternal_StorageVersionCondition(in *StorageVersionCondition, out *apiserverinternal.StorageVersionCondition, s conversion.Scope) error {
+	return autoConvert_v1alpha1_StorageVersionCondition_To_apiserverinternal_StorageVersionCondition(in, out, s)
+}
+
+func autoConvert_apiserverinternal_StorageVersionCondition_To_v1alpha1_StorageVersionCondition(in *apiserverinternal.StorageVersionCondition, out *StorageVersionCondition, s conversion.Scope) error {
+	out.Type = StorageVersionConditionType(in.Type)
+	out.Status = ConditionStatus(in.Status)
+	out.ObservedGeneration = in.ObservedGeneration
+	out.LastTransitionTime = in.LastTransitionTime
+	out.Reason = in.Reason
+	out.Message = in.Message
+	return nil
+}
+
+// Convert_apiserverinternal_StorageVersionCondition_To_v1alpha1_StorageVersionCondition is an autogenerated conversion function.
+func Convert_apiserverinternal_StorageVersionCondition_To_v1alpha1_StorageVersionCondition(in *apiserverinternal.StorageVersionCondition, out *StorageVersionCondition, s conversion.Scope) error {
+	return autoConvert_apiserverinternal_StorageVersionCondition_To_v1alpha1_StorageVersionCondition(in, out, s)
+}
+
+func autoConvert_v1alpha1_StorageVersionList_To_apiserverinternal_StorageVersionList(in *StorageVersionList, out *apiserverinternal.StorageVersionList, s conversion.Scope) error {
+	out.ListMeta = in.ListMeta
+	out.Items = *(*[]apiserverinternal.StorageVersion)(unsafe.Pointer(&in.Items))
+	return nil
+}
+
+// Convert_v1alpha1_StorageVersionList_To_apiserverinternal_StorageVersionList is an autogenerated conversion function.
+func Convert_v1alpha1_StorageVersionList_To_apiserverinternal_StorageVersionList(in *StorageVersionList, out *apiserverinternal.StorageVersionList, s conversion.Scope) error {
+	return autoConvert_v1alpha1_StorageVersionList_To_apiserverinternal_StorageVersionList(in, out, s)
+}
+
+func autoConvert_apiserverinternal_StorageVersionList_To_v1alpha1_StorageVersionList(in *apiserverinternal.StorageVersionList, out *StorageVersionList, s conversion.Scope) error {
+	out.ListMeta = in.ListMeta
+	out.Items = *(*[]StorageVersion)(unsafe.Pointer(&in.Items))
+	return nil
+}
+
+// Convert_apiserverinternal_StorageVersionList_To_v1alpha1_StorageVersionList is an autogenerated conversion function.
+func Convert_apiserverinternal_StorageVersionList_To_v1alpha1_StorageVersionList(in *apiserverinternal.StorageVersionList, out *StorageVersionList, s conversion.Scope) error {
+	return autoConvert_apiserverinternal_StorageVersionList_To_v1alpha1_StorageVersionList(in, out, s)
+}
+
+func autoConvert_v1alpha1_StorageVersionSpec_To_apiserverinternal_StorageVersionSpec(in *StorageVersionSpec, out *apiserverinternal.StorageVersionSpec, s conversion.Scope) error {
+	return nil
+}
+
+// Convert_v1alpha1_StorageVersionSpec_To_apiserverinternal_StorageVersionSpec is an autogenerated conversion function.
+func Convert_v1alpha1_StorageVersionSpec_To_apiserverinternal_StorageVersionSpec(in *StorageVersionSpec, out *apiserverinternal.StorageVersionSpec, s conversion.Scope) error {
+	return autoConvert_v1alpha1_StorageVersionSpec_To_apiserverinternal_StorageVersionSpec(in, out, s)
+}
+
+func autoConvert_apiserverinternal_StorageVersionSpec_To_v1alpha1_StorageVersionSpec(in *apiserverinternal.StorageVersionSpec, out *StorageVersionSpec, s conversion.Scope) error {
+	return nil
+}
+
+// Convert_apiserverinternal_StorageVersionSpec_To_v1alpha1_StorageVersionSpec is an autogenerated conversion function.
+func Convert_apiserverinternal_StorageVersionSpec_To_v1alpha1_StorageVersionSpec(in *apiserverinternal.StorageVersionSpec, out *StorageVersionSpec, s conversion.Scope) error {
+	return autoConvert_apiserverinternal_StorageVersionSpec_To_v1alpha1_StorageVersionSpec(in, out, s)
+}
+
+func autoConvert_v1alpha1_StorageVersionStatus_To_apiserverinternal_StorageVersionStatus(in *StorageVersionStatus, out *apiserverinternal.StorageVersionStatus, s conversion.Scope) error {
+	out.StorageVersions = *(*[]apiserverinternal.ServerStorageVersion)(unsafe.Pointer(&in.StorageVersions))
+	out.CommonEncodingVersion = (*string)(unsafe.Pointer(in.CommonEncodingVersion))
+	out.Conditions = *(*[]apiserverinternal.StorageVersionCondition)(unsafe.Pointer(&in.Conditions))
+	return nil
+}
+
+// Convert_v1alpha1_StorageVersionStatus_To_apiserverinternal_StorageVersionStatus is an autogenerated conversion function.
+func Convert_v1alpha1_StorageVersionStatus_To_apiserverinternal_StorageVersionStatus(in *StorageVersionStatus, out *apiserverinternal.StorageVersionStatus, s conversion.Scope) error {
+	return autoConvert_v1alpha1_StorageVersionStatus_To_apiserverinternal_StorageVersionStatus(in, out, s)
+}
+
+func autoConvert_apiserverinternal_StorageVersionStatus_To_v1alpha1_StorageVersionStatus(in *apiserverinternal.StorageVersionStatus, out *StorageVersionStatus, s conversion.Scope) error {
+	out.StorageVersions = *(*[]ServerStorageVersion)(unsafe.Pointer(&in.StorageVersions))
+	out.CommonEncodingVersion = (*string)(unsafe.Pointer(in.CommonEncodingVersion))
+	out.Conditions = *(*[]StorageVersionCondition)(unsafe.Pointer(&in.Conditions))
+	return nil
+}
+
+// Convert_apiserverinternal_StorageVersionStatus_To_v1alpha1_StorageVersionStatus is an autogenerated conversion function.
+func Convert_apiserverinternal_StorageVersionStatus_To_v1alpha1_StorageVersionStatus(in *apiserverinternal.StorageVersionStatus, out *StorageVersionStatus, s conversion.Scope) error {
+	return autoConvert_apiserverinternal_StorageVersionStatus_To_v1alpha1_StorageVersionStatus(in, out, s)
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1/zz_generated.deepcopy.go

@@ -0,0 +1,175 @@
+// +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
+
+import (
+	runtime "k8s.io/apimachinery/pkg/runtime"
+)
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *ServerStorageVersion) DeepCopyInto(out *ServerStorageVersion) {
+	*out = *in
+	if in.DecodableVersions != nil {
+		in, out := &in.DecodableVersions, &out.DecodableVersions
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ServerStorageVersion.
+func (in *ServerStorageVersion) DeepCopy() *ServerStorageVersion {
+	if in == nil {
+		return nil
+	}
+	out := new(ServerStorageVersion)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersion) DeepCopyInto(out *StorageVersion) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ObjectMeta.DeepCopyInto(&out.ObjectMeta)
+	out.Spec = in.Spec
+	in.Status.DeepCopyInto(&out.Status)
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersion.
+func (in *StorageVersion) DeepCopy() *StorageVersion {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersion)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *StorageVersion) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersionCondition) DeepCopyInto(out *StorageVersionCondition) {
+	*out = *in
+	in.LastTransitionTime.DeepCopyInto(&out.LastTransitionTime)
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersionCondition.
+func (in *StorageVersionCondition) DeepCopy() *StorageVersionCondition {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersionCondition)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersionList) DeepCopyInto(out *StorageVersionList) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ListMeta.DeepCopyInto(&out.ListMeta)
+	if in.Items != nil {
+		in, out := &in.Items, &out.Items
+		*out = make([]StorageVersion, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersionList.
+func (in *StorageVersionList) DeepCopy() *StorageVersionList {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersionList)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *StorageVersionList) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersionSpec) DeepCopyInto(out *StorageVersionSpec) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersionSpec.
+func (in *StorageVersionSpec) DeepCopy() *StorageVersionSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersionSpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersionStatus) DeepCopyInto(out *StorageVersionStatus) {
+	*out = *in
+	if in.StorageVersions != nil {
+		in, out := &in.StorageVersions, &out.StorageVersions
+		*out = make([]ServerStorageVersion, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+	if in.CommonEncodingVersion != nil {
+		in, out := &in.CommonEncodingVersion, &out.CommonEncodingVersion
+		*out = new(string)
+		**out = **in
+	}
+	if in.Conditions != nil {
+		in, out := &in.Conditions, &out.Conditions
+		*out = make([]StorageVersionCondition, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersionStatus.
+func (in *StorageVersionStatus) DeepCopy() *StorageVersionStatus {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersionStatus)
+	in.DeepCopyInto(out)
+	return out
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1/zz_generated.defaults.go

@@ -0,0 +1,32 @@
+// +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 defaulter-gen. DO NOT EDIT.
+
+package v1alpha1
+
+import (
+	runtime "k8s.io/apimachinery/pkg/runtime"
+)
+
+// RegisterDefaults adds defaulters functions to the given scheme.
+// Public to allow building arbitrary schemes.
+// All generated defaulters are covering - they call all nested defaulters.
+func RegisterDefaults(scheme *runtime.Scheme) error {
+	return nil
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/validation/BUILD

@@ -0,0 +1,39 @@
+package(default_visibility = ["//visibility:public"])
+
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["validation.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/apis/apiserverinternal/validation",
+    importpath = "k8s.io/apiserver/pkg/apis/apiserverinternal/validation",
+    deps = [
+        "//staging/src/k8s.io/apimachinery/pkg/api/validation:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["validation_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal:go_default_library",
+    ],
+)

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/validation/validation.go

@@ -0,0 +1,128 @@
+/*
+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 validation
+
+import (
+	"fmt"
+	"strings"
+
+	apimachineryvalidation "k8s.io/apimachinery/pkg/api/validation"
+	"k8s.io/apimachinery/pkg/util/validation"
+	utilvalidation "k8s.io/apimachinery/pkg/util/validation"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/apiserver/pkg/apis/apiserverinternal"
+)
+
+// ValidateStorageVersion validate the storage version object.
+func ValidateStorageVersion(sv *apiserverinternal.StorageVersion) field.ErrorList {
+	var allErrs field.ErrorList
+	allErrs = append(allErrs, validateStorageVersionStatus(sv.Status, field.NewPath("status"))...)
+	return allErrs
+}
+
+func validateStorageVersionStatus(ss apiserverinternal.StorageVersionStatus, fldPath *field.Path) field.ErrorList {
+	var allErrs field.ErrorList
+	for i, ssv := range ss.StorageVersions {
+		allErrs = append(allErrs, validateServerStorageVersion(ssv, fldPath.Child("storageVersions").Index(i))...)
+	}
+	if err := validateCommonVersion(ss, fldPath); err != nil {
+		allErrs = append(allErrs, err)
+	}
+	allErrs = append(allErrs, validateStorageVersionCondition(ss.Conditions, fldPath)...)
+	return allErrs
+}
+
+func validateServerStorageVersion(ssv apiserverinternal.ServerStorageVersion, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+	for _, msg := range apimachineryvalidation.NameIsDNSSubdomain(ssv.APIServerID, false) {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("apiServerID"), ssv.APIServerID, msg))
+	}
+	if errs := utilvalidation.IsDNS1035Label(ssv.EncodingVersion); len(errs) > 0 {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("encodingVersion"), ssv.EncodingVersion, strings.Join(errs, ",")))
+	}
+
+	found := false
+	for i, dv := range ssv.DecodableVersions {
+		if errs := utilvalidation.IsDNS1035Label(dv); len(errs) > 0 {
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("decodableVersions").Index(i), dv, strings.Join(errs, ",")))
+		}
+		if dv == ssv.EncodingVersion {
+			found = true
+		}
+	}
+	if !found {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("decodableVersions"), ssv.DecodableVersions, fmt.Sprintf("decodableVersions must include encodingVersion %s", ssv.EncodingVersion)))
+	}
+	return allErrs
+}
+
+func commonVersion(ssv []apiserverinternal.ServerStorageVersion) *string {
+	if len(ssv) == 0 {
+		return nil
+	}
+	commonVersion := ssv[0].EncodingVersion
+	for _, v := range ssv[1:] {
+		if v.EncodingVersion != commonVersion {
+			return nil
+		}
+	}
+	return &commonVersion
+}
+
+func validateCommonVersion(svs apiserverinternal.StorageVersionStatus, fldPath *field.Path) *field.Error {
+	actualCommonVersion := commonVersion(svs.StorageVersions)
+	if actualCommonVersion == nil && svs.CommonEncodingVersion == nil {
+		return nil
+	}
+	if actualCommonVersion == nil && svs.CommonEncodingVersion != nil {
+		return field.Invalid(fldPath.Child("commonEncodingVersion"), *svs.CommonEncodingVersion, "should be nil if servers do not agree on the same encoding version, or if there is no server reporting the supported versions yet")
+	}
+	if actualCommonVersion != nil && svs.CommonEncodingVersion == nil {
+		return field.Invalid(fldPath.Child("commonEncodingVersion"), svs.CommonEncodingVersion, fmt.Sprintf("the common encoding version is %s", *actualCommonVersion))
+	}
+	if actualCommonVersion != nil && svs.CommonEncodingVersion != nil && *actualCommonVersion != *svs.CommonEncodingVersion {
+		return field.Invalid(fldPath.Child("commonEncodingVersion"), *svs.CommonEncodingVersion, fmt.Sprintf("the actual common encoding version is %s", *actualCommonVersion))
+	}
+	return nil
+}
+
+func validateStorageVersionCondition(conditions []apiserverinternal.StorageVersionCondition, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+	// We do not verify that the condition type or the condition status is
+	// a predefined one because we might add more type or status later.
+	seenType := make(map[apiserverinternal.StorageVersionConditionType]int)
+	for i, condition := range conditions {
+		if ii, ok := seenType[condition.Type]; ok {
+			allErrs = append(allErrs, field.Invalid(fldPath.Index(i).Child("type"), string(condition.Type),
+				fmt.Sprintf("the type of the condition is not unique, it also appears in conditions[%d]", ii)))
+		}
+		seenType[condition.Type] = i
+		for _, msg := range validation.IsQualifiedName(string(condition.Type)) {
+			allErrs = append(allErrs, field.Invalid(fldPath.Index(i).Child("type"), string(condition.Type), msg))
+		}
+		for _, msg := range validation.IsQualifiedName(string(condition.Status)) {
+			allErrs = append(allErrs, field.Invalid(fldPath.Index(i).Child("status"), string(condition.Type), msg))
+		}
+		if condition.Reason == "" {
+			allErrs = append(allErrs, field.Required(fldPath.Index(i).Child("reason"), "reason cannot be empty"))
+		}
+		if condition.Message == "" {
+			allErrs = append(allErrs, field.Required(fldPath.Index(i).Child("message"), "message cannot be empty"))
+		}
+	}
+	return allErrs
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/validation/validation_test.go

@@ -0,0 +1,286 @@
+/*
+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 validation
+
+import (
+	"strings"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/apiserver/pkg/apis/apiserverinternal"
+)
+
+func TestValidateServerStorageVersion(t *testing.T) {
+	cases := []struct {
+		ssv         apiserverinternal.ServerStorageVersion
+		expectedErr string
+	}{
+		{
+			ssv: apiserverinternal.ServerStorageVersion{
+				APIServerID:       "-fea",
+				EncodingVersion:   "v1alpha1",
+				DecodableVersions: []string{"v1alpha1", "v1"},
+			},
+			expectedErr: "apiServerID: Invalid value",
+		},
+		{
+			ssv: apiserverinternal.ServerStorageVersion{
+				APIServerID:       "fea",
+				EncodingVersion:   "v1alpha1",
+				DecodableVersions: []string{"v1beta1", "v1"},
+			},
+			expectedErr: "decodableVersions must include encodingVersion",
+		},
+		{
+			ssv: apiserverinternal.ServerStorageVersion{
+				APIServerID:       "fea",
+				EncodingVersion:   "v1alpha1",
+				DecodableVersions: []string{"v1alpha1", "v1", "-fea"},
+			},
+			expectedErr: "decodableVersions[2]: Invalid value",
+		},
+		{
+			ssv: apiserverinternal.ServerStorageVersion{
+				APIServerID:       "fea",
+				EncodingVersion:   "v1alpha1",
+				DecodableVersions: []string{"v1alpha1", "v1"},
+			},
+			expectedErr: "",
+		},
+	}
+
+	for _, tc := range cases {
+		err := validateServerStorageVersion(tc.ssv, field.NewPath("")).ToAggregate()
+		if err == nil && len(tc.expectedErr) == 0 {
+			continue
+		}
+		if err != nil && len(tc.expectedErr) == 0 {
+			t.Errorf("unexpected error %v", err)
+			continue
+		}
+		if err == nil && len(tc.expectedErr) != 0 {
+			t.Errorf("unexpected empty error")
+			continue
+		}
+		if !strings.Contains(err.Error(), tc.expectedErr) {
+			t.Errorf("expected error to contain %s, got %s", tc.expectedErr, err)
+		}
+	}
+}
+
+func TestValidateCommonVersion(t *testing.T) {
+	cases := []struct {
+		status      apiserverinternal.StorageVersionStatus
+		expectedErr string
+	}{
+		{
+			status: apiserverinternal.StorageVersionStatus{
+				StorageVersions:       []apiserverinternal.ServerStorageVersion{},
+				CommonEncodingVersion: func() *string { a := "v1alpha1"; return &a }(),
+			},
+			expectedErr: "should be nil if servers do not agree on the same encoding version, or if there is no server reporting the supported versions yet",
+		},
+		{
+			status: apiserverinternal.StorageVersionStatus{
+				StorageVersions: []apiserverinternal.ServerStorageVersion{
+					{
+						APIServerID:     "1",
+						EncodingVersion: "v1alpha1",
+					},
+					{
+						APIServerID:     "2",
+						EncodingVersion: "v1",
+					},
+				},
+				CommonEncodingVersion: func() *string { a := "v1alpha1"; return &a }(),
+			},
+			expectedErr: "should be nil if servers do not agree on the same encoding version, or if there is no server reporting the supported versions yet",
+		},
+		{
+			status: apiserverinternal.StorageVersionStatus{
+				StorageVersions: []apiserverinternal.ServerStorageVersion{
+					{
+						APIServerID:     "1",
+						EncodingVersion: "v1alpha1",
+					},
+					{
+						APIServerID:     "2",
+						EncodingVersion: "v1alpha1",
+					},
+				},
+				CommonEncodingVersion: nil,
+			},
+			expectedErr: "Invalid value: \"null\": the common encoding version is v1alpha1",
+		},
+		{
+			status: apiserverinternal.StorageVersionStatus{
+				StorageVersions: []apiserverinternal.ServerStorageVersion{
+					{
+						APIServerID:     "1",
+						EncodingVersion: "v1alpha1",
+					},
+					{
+						APIServerID:     "2",
+						EncodingVersion: "v1alpha1",
+					},
+				},
+				CommonEncodingVersion: func() *string { a := "v1"; return &a }(),
+			},
+			expectedErr: "Invalid value: \"v1\": the actual common encoding version is v1alpha1",
+		},
+		{
+			status: apiserverinternal.StorageVersionStatus{
+				StorageVersions: []apiserverinternal.ServerStorageVersion{
+					{
+						APIServerID:     "1",
+						EncodingVersion: "v1alpha1",
+					},
+					{
+						APIServerID:     "2",
+						EncodingVersion: "v1alpha1",
+					},
+				},
+				CommonEncodingVersion: func() *string { a := "v1alpha1"; return &a }(),
+			},
+			expectedErr: "",
+		},
+		{
+			status: apiserverinternal.StorageVersionStatus{
+				StorageVersions: []apiserverinternal.ServerStorageVersion{
+					{
+						APIServerID:     "1",
+						EncodingVersion: "v1alpha1",
+					},
+				},
+				CommonEncodingVersion: func() *string { a := "v1alpha1"; return &a }(),
+			},
+			expectedErr: "",
+		},
+	}
+	for _, tc := range cases {
+		err := validateCommonVersion(tc.status, field.NewPath(""))
+		if err == nil && len(tc.expectedErr) == 0 {
+			continue
+		}
+		if err != nil && len(tc.expectedErr) == 0 {
+			t.Errorf("unexpected error %v", err)
+			continue
+		}
+		if err == nil && len(tc.expectedErr) != 0 {
+			t.Errorf("unexpected empty error")
+			continue
+		}
+		if !strings.Contains(err.Error(), tc.expectedErr) {
+			t.Errorf("expected error to contain %s, got %s", tc.expectedErr, err)
+		}
+	}
+}
+
+func TestValidateStorageVersionCondition(t *testing.T) {
+	cases := []struct {
+		conditions  []apiserverinternal.StorageVersionCondition
+		expectedErr string
+	}{
+		{
+			conditions: []apiserverinternal.StorageVersionCondition{
+				{
+					Type:    "-fea",
+					Status:  "True",
+					Reason:  "unknown",
+					Message: "unknown",
+				},
+			},
+			expectedErr: "type: Invalid value",
+		},
+		{
+			conditions: []apiserverinternal.StorageVersionCondition{
+				{
+					Type:    "fea",
+					Status:  "-True",
+					Reason:  "unknown",
+					Message: "unknown",
+				},
+			},
+			expectedErr: "status: Invalid value",
+		},
+		{
+			conditions: []apiserverinternal.StorageVersionCondition{
+				{
+					Type:    "fea",
+					Status:  "True",
+					Message: "unknown",
+				},
+			},
+			expectedErr: "Required value: reason cannot be empty",
+		},
+		{
+			conditions: []apiserverinternal.StorageVersionCondition{
+				{
+					Type:   "fea",
+					Status: "True",
+					Reason: "unknown",
+				},
+			},
+			expectedErr: "Required value: message cannot be empty",
+		},
+		{
+			conditions: []apiserverinternal.StorageVersionCondition{
+				{
+					Type:    "fea",
+					Status:  "True",
+					Reason:  "unknown",
+					Message: "unknown",
+				},
+				{
+					Type:    "fea",
+					Status:  "True",
+					Reason:  "unknown",
+					Message: "unknown",
+				},
+			},
+			expectedErr: `"fea": the type of the condition is not unique, it also appears in conditions[0]`,
+		},
+		{
+			conditions: []apiserverinternal.StorageVersionCondition{
+				{
+					Type:    "fea",
+					Status:  "True",
+					Reason:  "unknown",
+					Message: "unknown",
+				},
+			},
+			expectedErr: "",
+		},
+	}
+	for _, tc := range cases {
+		err := validateStorageVersionCondition(tc.conditions, field.NewPath("")).ToAggregate()
+		if err == nil && len(tc.expectedErr) == 0 {
+			continue
+		}
+		if err != nil && len(tc.expectedErr) == 0 {
+			t.Errorf("unexpected error %v", err)
+			continue
+		}
+		if err == nil && len(tc.expectedErr) != 0 {
+			t.Errorf("unexpected empty error")
+			continue
+		}
+		if !strings.Contains(err.Error(), tc.expectedErr) {
+			t.Errorf("expected error to contain %s, got %s", tc.expectedErr, err)
+		}
+	}
+}

staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/zz_generated.deepcopy.go

@@ -0,0 +1,175 @@
+// +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 apiserverinternal
+
+import (
+	runtime "k8s.io/apimachinery/pkg/runtime"
+)
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *ServerStorageVersion) DeepCopyInto(out *ServerStorageVersion) {
+	*out = *in
+	if in.DecodableVersions != nil {
+		in, out := &in.DecodableVersions, &out.DecodableVersions
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ServerStorageVersion.
+func (in *ServerStorageVersion) DeepCopy() *ServerStorageVersion {
+	if in == nil {
+		return nil
+	}
+	out := new(ServerStorageVersion)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersion) DeepCopyInto(out *StorageVersion) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ObjectMeta.DeepCopyInto(&out.ObjectMeta)
+	out.Spec = in.Spec
+	in.Status.DeepCopyInto(&out.Status)
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersion.
+func (in *StorageVersion) DeepCopy() *StorageVersion {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersion)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *StorageVersion) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersionCondition) DeepCopyInto(out *StorageVersionCondition) {
+	*out = *in
+	in.LastTransitionTime.DeepCopyInto(&out.LastTransitionTime)
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersionCondition.
+func (in *StorageVersionCondition) DeepCopy() *StorageVersionCondition {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersionCondition)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersionList) DeepCopyInto(out *StorageVersionList) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ListMeta.DeepCopyInto(&out.ListMeta)
+	if in.Items != nil {
+		in, out := &in.Items, &out.Items
+		*out = make([]StorageVersion, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersionList.
+func (in *StorageVersionList) DeepCopy() *StorageVersionList {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersionList)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *StorageVersionList) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersionSpec) DeepCopyInto(out *StorageVersionSpec) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersionSpec.
+func (in *StorageVersionSpec) DeepCopy() *StorageVersionSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersionSpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *StorageVersionStatus) DeepCopyInto(out *StorageVersionStatus) {
+	*out = *in
+	if in.StorageVersions != nil {
+		in, out := &in.StorageVersions, &out.StorageVersions
+		*out = make([]ServerStorageVersion, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+	if in.CommonEncodingVersion != nil {
+		in, out := &in.CommonEncodingVersion, &out.CommonEncodingVersion
+		*out = new(string)
+		**out = **in
+	}
+	if in.Conditions != nil {
+		in, out := &in.Conditions, &out.Conditions
+		*out = make([]StorageVersionCondition, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new StorageVersionStatus.
+func (in *StorageVersionStatus) DeepCopy() *StorageVersionStatus {
+	if in == nil {
+		return nil
+	}
+	out := new(StorageVersionStatus)
+	in.DeepCopyInto(out)
+	return out
+}