diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/endpoints/openapi/OWNERS b/metrics-server/vendor/k8s.io/apiserver/pkg/endpoints/openapi/OWNERS
new file mode 100755
index 0000000..4126a6b
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/endpoints/openapi/OWNERS
@@ -0,0 +1,2 @@
+reviewers:
+- mbohlool
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/endpoints/openapi/openapi.go b/metrics-server/vendor/k8s.io/apiserver/pkg/endpoints/openapi/openapi.go
new file mode 100644
index 0000000..e512f29
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/endpoints/openapi/openapi.go
@@ -0,0 +1,179 @@
+/*
+Copyright 2016 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 openapi
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"sort"
+	"strings"
+	"unicode"
+
+	restful "github.com/emicklei/go-restful"
+	"github.com/go-openapi/spec"
+
+	"k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/kube-openapi/pkg/util"
+)
+
+var verbs = util.NewTrie([]string{"get", "log", "read", "replace", "patch", "delete", "deletecollection", "watch", "connect", "proxy", "list", "create", "patch"})
+
+const (
+	extensionGVK = "x-kubernetes-group-version-kind"
+)
+
+// ToValidOperationID makes an string a valid op ID (e.g. removing punctuations and whitespaces and make it camel case)
+func ToValidOperationID(s string, capitalizeFirstLetter bool) string {
+	var buffer bytes.Buffer
+	capitalize := capitalizeFirstLetter
+	for i, r := range s {
+		if unicode.IsLetter(r) || r == '_' || (i != 0 && unicode.IsDigit(r)) {
+			if capitalize {
+				buffer.WriteRune(unicode.ToUpper(r))
+				capitalize = false
+			} else {
+				buffer.WriteRune(r)
+			}
+		} else {
+			capitalize = true
+		}
+	}
+	return buffer.String()
+}
+
+// GetOperationIDAndTags returns a customize operation ID and a list of tags for kubernetes API server's OpenAPI spec to prevent duplicate IDs.
+func GetOperationIDAndTags(r *restful.Route) (string, []string, error) {
+	op := r.Operation
+	path := r.Path
+	var tags []string
+	prefix, exists := verbs.GetPrefix(op)
+	if !exists {
+		return op, tags, fmt.Errorf("operation names should start with a verb. Cannot determine operation verb from %v", op)
+	}
+	op = op[len(prefix):]
+	parts := strings.Split(strings.Trim(path, "/"), "/")
+	// Assume /api is /apis/core, remove this when we actually server /api/... on /apis/core/...
+	if len(parts) >= 1 && parts[0] == "api" {
+		parts = append([]string{"apis", "core"}, parts[1:]...)
+	}
+	if len(parts) >= 2 && parts[0] == "apis" {
+		trimmed := strings.TrimSuffix(parts[1], ".k8s.io")
+		prefix = prefix + ToValidOperationID(trimmed, prefix != "")
+		tag := ToValidOperationID(trimmed, false)
+		if len(parts) > 2 {
+			prefix = prefix + ToValidOperationID(parts[2], prefix != "")
+			tag = tag + "_" + ToValidOperationID(parts[2], false)
+		}
+		tags = append(tags, tag)
+	} else if len(parts) >= 1 {
+		tags = append(tags, ToValidOperationID(parts[0], false))
+	}
+	return prefix + ToValidOperationID(op, prefix != ""), tags, nil
+}
+
+type groupVersionKinds []v1.GroupVersionKind
+
+func (s groupVersionKinds) Len() int {
+	return len(s)
+}
+
+func (s groupVersionKinds) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s groupVersionKinds) Less(i, j int) bool {
+	if s[i].Group == s[j].Group {
+		if s[i].Version == s[j].Version {
+			return s[i].Kind < s[j].Kind
+		}
+		return s[i].Version < s[j].Version
+	}
+	return s[i].Group < s[j].Group
+}
+
+// DefinitionNamer is the type to customize OpenAPI definition name.
+type DefinitionNamer struct {
+	typeGroupVersionKinds map[string]groupVersionKinds
+}
+
+func gvkConvert(gvk schema.GroupVersionKind) v1.GroupVersionKind {
+	return v1.GroupVersionKind{
+		Group:   gvk.Group,
+		Version: gvk.Version,
+		Kind:    gvk.Kind,
+	}
+}
+
+func friendlyName(name string) string {
+	nameParts := strings.Split(name, "/")
+	// Reverse first part. e.g., io.k8s... instead of k8s.io...
+	if len(nameParts) > 0 && strings.Contains(nameParts[0], ".") {
+		parts := strings.Split(nameParts[0], ".")
+		for i, j := 0, len(parts)-1; i < j; i, j = i+1, j-1 {
+			parts[i], parts[j] = parts[j], parts[i]
+		}
+		nameParts[0] = strings.Join(parts, ".")
+	}
+	return strings.Join(nameParts, ".")
+}
+
+func typeName(t reflect.Type) string {
+	path := t.PkgPath()
+	if strings.Contains(path, "/vendor/") {
+		path = path[strings.Index(path, "/vendor/")+len("/vendor/"):]
+	}
+	return fmt.Sprintf("%s.%s", path, t.Name())
+}
+
+// NewDefinitionNamer constructs a new DefinitionNamer to be used to customize OpenAPI spec.
+func NewDefinitionNamer(schemes ...*runtime.Scheme) *DefinitionNamer {
+	ret := &DefinitionNamer{
+		typeGroupVersionKinds: map[string]groupVersionKinds{},
+	}
+	for _, s := range schemes {
+		for gvk, rtype := range s.AllKnownTypes() {
+			newGVK := gvkConvert(gvk)
+			exists := false
+			for _, existingGVK := range ret.typeGroupVersionKinds[typeName(rtype)] {
+				if newGVK == existingGVK {
+					exists = true
+					break
+				}
+			}
+			if !exists {
+				ret.typeGroupVersionKinds[typeName(rtype)] = append(ret.typeGroupVersionKinds[typeName(rtype)], newGVK)
+			}
+		}
+	}
+	for _, gvk := range ret.typeGroupVersionKinds {
+		sort.Sort(gvk)
+	}
+	return ret
+}
+
+// GetDefinitionName returns the name and tags for a given definition
+func (d *DefinitionNamer) GetDefinitionName(name string) (string, spec.Extensions) {
+	if groupVersionKinds, ok := d.typeGroupVersionKinds[name]; ok {
+		return friendlyName(name), spec.Extensions{
+			extensionGVK: []v1.GroupVersionKind(groupVersionKinds),
+		}
+	}
+	return friendlyName(name), nil
+}