rebase: update kubernetes to 1.28.0 in main

updating kubernetes to 1.28.0
in the main repo.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/github.com/google/gnostic-models/compiler/README.md

@@ -0,0 +1,4 @@
+# Compiler support code
+
+This directory contains compiler support code used by Gnostic and Gnostic
+extensions.

vendor/github.com/google/gnostic-models/compiler/context.go

@@ -0,0 +1,49 @@
+// Copyright 2017 Google LLC. All Rights Reserved.
+//
+// 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 compiler
+
+import (
+	yaml "gopkg.in/yaml.v3"
+)
+
+// Context contains state of the compiler as it traverses a document.
+type Context struct {
+	Parent            *Context
+	Name              string
+	Node              *yaml.Node
+	ExtensionHandlers *[]ExtensionHandler
+}
+
+// NewContextWithExtensions returns a new object representing the compiler state
+func NewContextWithExtensions(name string, node *yaml.Node, parent *Context, extensionHandlers *[]ExtensionHandler) *Context {
+	return &Context{Name: name, Node: node, Parent: parent, ExtensionHandlers: extensionHandlers}
+}
+
+// NewContext returns a new object representing the compiler state
+func NewContext(name string, node *yaml.Node, parent *Context) *Context {
+	if parent != nil {
+		return &Context{Name: name, Node: node, Parent: parent, ExtensionHandlers: parent.ExtensionHandlers}
+	}
+	return &Context{Name: name, Parent: parent, ExtensionHandlers: nil}
+}
+
+// Description returns a text description of the compiler state
+func (context *Context) Description() string {
+	name := context.Name
+	if context.Parent != nil {
+		name = context.Parent.Description() + "." + name
+	}
+	return name
+}

vendor/github.com/google/gnostic-models/compiler/error.go

@@ -0,0 +1,70 @@
+// Copyright 2017 Google LLC. All Rights Reserved.
+//
+// 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 compiler
+
+import "fmt"
+
+// Error represents compiler errors and their location in the document.
+type Error struct {
+	Context *Context
+	Message string
+}
+
+// NewError creates an Error.
+func NewError(context *Context, message string) *Error {
+	return &Error{Context: context, Message: message}
+}
+
+func (err *Error) locationDescription() string {
+	if err.Context.Node != nil {
+		return fmt.Sprintf("[%d,%d] %s", err.Context.Node.Line, err.Context.Node.Column, err.Context.Description())
+	}
+	return err.Context.Description()
+}
+
+// Error returns the string value of an Error.
+func (err *Error) Error() string {
+	if err.Context == nil {
+		return err.Message
+	}
+	return err.locationDescription() + " " + err.Message
+}
+
+// ErrorGroup is a container for groups of Error values.
+type ErrorGroup struct {
+	Errors []error
+}
+
+// NewErrorGroupOrNil returns a new ErrorGroup for a slice of errors or nil if the slice is empty.
+func NewErrorGroupOrNil(errors []error) error {
+	if len(errors) == 0 {
+		return nil
+	} else if len(errors) == 1 {
+		return errors[0]
+	} else {
+		return &ErrorGroup{Errors: errors}
+	}
+}
+
+func (group *ErrorGroup) Error() string {
+	result := ""
+	for i, err := range group.Errors {
+		if i > 0 {
+			result += "\n"
+		}
+		result += err.Error()
+	}
+	return result
+}

vendor/github.com/google/gnostic-models/compiler/extensions.go

@@ -0,0 +1,86 @@
+// Copyright 2017 Google LLC. All Rights Reserved.
+//
+// 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 compiler
+
+import (
+	"bytes"
+	"fmt"
+	"os/exec"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes/any"
+	yaml "gopkg.in/yaml.v3"
+
+	extensions "github.com/google/gnostic-models/extensions"
+)
+
+// ExtensionHandler describes a binary that is called by the compiler to handle specification extensions.
+type ExtensionHandler struct {
+	Name string
+}
+
+// CallExtension calls a binary extension handler.
+func CallExtension(context *Context, in *yaml.Node, extensionName string) (handled bool, response *any.Any, err error) {
+	if context == nil || context.ExtensionHandlers == nil {
+		return false, nil, nil
+	}
+	handled = false
+	for _, handler := range *(context.ExtensionHandlers) {
+		response, err = handler.handle(in, extensionName)
+		if response == nil {
+			continue
+		} else {
+			handled = true
+			break
+		}
+	}
+	return handled, response, err
+}
+
+func (extensionHandlers *ExtensionHandler) handle(in *yaml.Node, extensionName string) (*any.Any, error) {
+	if extensionHandlers.Name != "" {
+		yamlData, _ := yaml.Marshal(in)
+		request := &extensions.ExtensionHandlerRequest{
+			CompilerVersion: &extensions.Version{
+				Major: 0,
+				Minor: 1,
+				Patch: 0,
+			},
+			Wrapper: &extensions.Wrapper{
+				Version:       "unknown", // TODO: set this to the type/version of spec being parsed.
+				Yaml:          string(yamlData),
+				ExtensionName: extensionName,
+			},
+		}
+		requestBytes, _ := proto.Marshal(request)
+		cmd := exec.Command(extensionHandlers.Name)
+		cmd.Stdin = bytes.NewReader(requestBytes)
+		output, err := cmd.Output()
+		if err != nil {
+			return nil, err
+		}
+		response := &extensions.ExtensionHandlerResponse{}
+		err = proto.Unmarshal(output, response)
+		if err != nil || !response.Handled {
+			return nil, err
+		}
+		if len(response.Errors) != 0 {
+			return nil, fmt.Errorf("Errors when parsing: %+v for field %s by vendor extension handler %s. Details %+v", in, extensionName, extensionHandlers.Name, strings.Join(response.Errors, ","))
+		}
+		return response.Value, nil
+	}
+	return nil, nil
+}

vendor/github.com/google/gnostic-models/compiler/helpers.go

@@ -0,0 +1,397 @@
+// Copyright 2017 Google LLC. All Rights Reserved.
+//
+// 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 compiler
+
+import (
+	"fmt"
+	"regexp"
+	"sort"
+	"strconv"
+
+	"gopkg.in/yaml.v3"
+
+	"github.com/google/gnostic-models/jsonschema"
+)
+
+// compiler helper functions, usually called from generated code
+
+// UnpackMap gets a *yaml.Node if possible.
+func UnpackMap(in *yaml.Node) (*yaml.Node, bool) {
+	if in == nil {
+		return nil, false
+	}
+	return in, true
+}
+
+// SortedKeysForMap returns the sorted keys of a yamlv2.MapSlice.
+func SortedKeysForMap(m *yaml.Node) []string {
+	keys := make([]string, 0)
+	if m.Kind == yaml.MappingNode {
+		for i := 0; i < len(m.Content); i += 2 {
+			keys = append(keys, m.Content[i].Value)
+		}
+	}
+	sort.Strings(keys)
+	return keys
+}
+
+// MapHasKey returns true if a yamlv2.MapSlice contains a specified key.
+func MapHasKey(m *yaml.Node, key string) bool {
+	if m == nil {
+		return false
+	}
+	if m.Kind == yaml.MappingNode {
+		for i := 0; i < len(m.Content); i += 2 {
+			itemKey := m.Content[i].Value
+			if key == itemKey {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// MapValueForKey gets the value of a map value for a specified key.
+func MapValueForKey(m *yaml.Node, key string) *yaml.Node {
+	if m == nil {
+		return nil
+	}
+	if m.Kind == yaml.MappingNode {
+		for i := 0; i < len(m.Content); i += 2 {
+			itemKey := m.Content[i].Value
+			if key == itemKey {
+				return m.Content[i+1]
+			}
+		}
+	}
+	return nil
+}
+
+// ConvertInterfaceArrayToStringArray converts an array of interfaces to an array of strings, if possible.
+func ConvertInterfaceArrayToStringArray(interfaceArray []interface{}) []string {
+	stringArray := make([]string, 0)
+	for _, item := range interfaceArray {
+		v, ok := item.(string)
+		if ok {
+			stringArray = append(stringArray, v)
+		}
+	}
+	return stringArray
+}
+
+// SequenceNodeForNode returns a node if it is a SequenceNode.
+func SequenceNodeForNode(node *yaml.Node) (*yaml.Node, bool) {
+	if node.Kind != yaml.SequenceNode {
+		return nil, false
+	}
+	return node, true
+}
+
+// BoolForScalarNode returns the bool value of a node.
+func BoolForScalarNode(node *yaml.Node) (bool, bool) {
+	if node == nil {
+		return false, false
+	}
+	if node.Kind == yaml.DocumentNode {
+		return BoolForScalarNode(node.Content[0])
+	}
+	if node.Kind != yaml.ScalarNode {
+		return false, false
+	}
+	if node.Tag != "!!bool" {
+		return false, false
+	}
+	v, err := strconv.ParseBool(node.Value)
+	if err != nil {
+		return false, false
+	}
+	return v, true
+}
+
+// IntForScalarNode returns the integer value of a node.
+func IntForScalarNode(node *yaml.Node) (int64, bool) {
+	if node == nil {
+		return 0, false
+	}
+	if node.Kind == yaml.DocumentNode {
+		return IntForScalarNode(node.Content[0])
+	}
+	if node.Kind != yaml.ScalarNode {
+		return 0, false
+	}
+	if node.Tag != "!!int" {
+		return 0, false
+	}
+	v, err := strconv.ParseInt(node.Value, 10, 64)
+	if err != nil {
+		return 0, false
+	}
+	return v, true
+}
+
+// FloatForScalarNode returns the float value of a node.
+func FloatForScalarNode(node *yaml.Node) (float64, bool) {
+	if node == nil {
+		return 0.0, false
+	}
+	if node.Kind == yaml.DocumentNode {
+		return FloatForScalarNode(node.Content[0])
+	}
+	if node.Kind != yaml.ScalarNode {
+		return 0.0, false
+	}
+	if (node.Tag != "!!int") && (node.Tag != "!!float") {
+		return 0.0, false
+	}
+	v, err := strconv.ParseFloat(node.Value, 64)
+	if err != nil {
+		return 0.0, false
+	}
+	return v, true
+}
+
+// StringForScalarNode returns the string value of a node.
+func StringForScalarNode(node *yaml.Node) (string, bool) {
+	if node == nil {
+		return "", false
+	}
+	if node.Kind == yaml.DocumentNode {
+		return StringForScalarNode(node.Content[0])
+	}
+	switch node.Kind {
+	case yaml.ScalarNode:
+		switch node.Tag {
+		case "!!int":
+			return node.Value, true
+		case "!!str":
+			return node.Value, true
+		case "!!timestamp":
+			return node.Value, true
+		case "!!null":
+			return "", true
+		default:
+			return "", false
+		}
+	default:
+		return "", false
+	}
+}
+
+// StringArrayForSequenceNode converts a sequence node to an array of strings, if possible.
+func StringArrayForSequenceNode(node *yaml.Node) []string {
+	stringArray := make([]string, 0)
+	for _, item := range node.Content {
+		v, ok := StringForScalarNode(item)
+		if ok {
+			stringArray = append(stringArray, v)
+		}
+	}
+	return stringArray
+}
+
+// MissingKeysInMap identifies which keys from a list of required keys are not in a map.
+func MissingKeysInMap(m *yaml.Node, requiredKeys []string) []string {
+	missingKeys := make([]string, 0)
+	for _, k := range requiredKeys {
+		if !MapHasKey(m, k) {
+			missingKeys = append(missingKeys, k)
+		}
+	}
+	return missingKeys
+}
+
+// InvalidKeysInMap returns keys in a map that don't match a list of allowed keys and patterns.
+func InvalidKeysInMap(m *yaml.Node, allowedKeys []string, allowedPatterns []*regexp.Regexp) []string {
+	invalidKeys := make([]string, 0)
+	if m == nil || m.Kind != yaml.MappingNode {
+		return invalidKeys
+	}
+	for i := 0; i < len(m.Content); i += 2 {
+		key := m.Content[i].Value
+		found := false
+		// does the key match an allowed key?
+		for _, allowedKey := range allowedKeys {
+			if key == allowedKey {
+				found = true
+				break
+			}
+		}
+		if !found {
+			// does the key match an allowed pattern?
+			for _, allowedPattern := range allowedPatterns {
+				if allowedPattern.MatchString(key) {
+					found = true
+					break
+				}
+			}
+			if !found {
+				invalidKeys = append(invalidKeys, key)
+			}
+		}
+	}
+	return invalidKeys
+}
+
+// NewNullNode creates a new Null node.
+func NewNullNode() *yaml.Node {
+	node := &yaml.Node{
+		Kind: yaml.ScalarNode,
+		Tag:  "!!null",
+	}
+	return node
+}
+
+// NewMappingNode creates a new Mapping node.
+func NewMappingNode() *yaml.Node {
+	return &yaml.Node{
+		Kind:    yaml.MappingNode,
+		Content: make([]*yaml.Node, 0),
+	}
+}
+
+// NewSequenceNode creates a new Sequence node.
+func NewSequenceNode() *yaml.Node {
+	node := &yaml.Node{
+		Kind:    yaml.SequenceNode,
+		Content: make([]*yaml.Node, 0),
+	}
+	return node
+}
+
+// NewScalarNodeForString creates a new node to hold a string.
+func NewScalarNodeForString(s string) *yaml.Node {
+	return &yaml.Node{
+		Kind:  yaml.ScalarNode,
+		Tag:   "!!str",
+		Value: s,
+	}
+}
+
+// NewSequenceNodeForStringArray creates a new node to hold an array of strings.
+func NewSequenceNodeForStringArray(strings []string) *yaml.Node {
+	node := &yaml.Node{
+		Kind:    yaml.SequenceNode,
+		Content: make([]*yaml.Node, 0),
+	}
+	for _, s := range strings {
+		node.Content = append(node.Content, NewScalarNodeForString(s))
+	}
+	return node
+}
+
+// NewScalarNodeForBool creates a new node to hold a bool.
+func NewScalarNodeForBool(b bool) *yaml.Node {
+	return &yaml.Node{
+		Kind:  yaml.ScalarNode,
+		Tag:   "!!bool",
+		Value: fmt.Sprintf("%t", b),
+	}
+}
+
+// NewScalarNodeForFloat creates a new node to hold a float.
+func NewScalarNodeForFloat(f float64) *yaml.Node {
+	return &yaml.Node{
+		Kind:  yaml.ScalarNode,
+		Tag:   "!!float",
+		Value: fmt.Sprintf("%g", f),
+	}
+}
+
+// NewScalarNodeForInt creates a new node to hold an integer.
+func NewScalarNodeForInt(i int64) *yaml.Node {
+	return &yaml.Node{
+		Kind:  yaml.ScalarNode,
+		Tag:   "!!int",
+		Value: fmt.Sprintf("%d", i),
+	}
+}
+
+// PluralProperties returns the string "properties" pluralized.
+func PluralProperties(count int) string {
+	if count == 1 {
+		return "property"
+	}
+	return "properties"
+}
+
+// StringArrayContainsValue returns true if a string array contains a specified value.
+func StringArrayContainsValue(array []string, value string) bool {
+	for _, item := range array {
+		if item == value {
+			return true
+		}
+	}
+	return false
+}
+
+// StringArrayContainsValues returns true if a string array contains all of a list of specified values.
+func StringArrayContainsValues(array []string, values []string) bool {
+	for _, value := range values {
+		if !StringArrayContainsValue(array, value) {
+			return false
+		}
+	}
+	return true
+}
+
+// StringValue returns the string value of an item.
+func StringValue(item interface{}) (value string, ok bool) {
+	value, ok = item.(string)
+	if ok {
+		return value, ok
+	}
+	intValue, ok := item.(int)
+	if ok {
+		return strconv.Itoa(intValue), true
+	}
+	return "", false
+}
+
+// Description returns a human-readable represention of an item.
+func Description(item interface{}) string {
+	value, ok := item.(*yaml.Node)
+	if ok {
+		return jsonschema.Render(value)
+	}
+	return fmt.Sprintf("%+v", item)
+}
+
+// Display returns a description of a node for use in error messages.
+func Display(node *yaml.Node) string {
+	switch node.Kind {
+	case yaml.ScalarNode:
+		switch node.Tag {
+		case "!!str":
+			return fmt.Sprintf("%s (string)", node.Value)
+		}
+	}
+	return fmt.Sprintf("%+v (%T)", node, node)
+}
+
+// Marshal creates a yaml version of a structure in our preferred style
+func Marshal(in *yaml.Node) []byte {
+	clearStyle(in)
+	//bytes, _ := yaml.Marshal(&yaml.Node{Kind: yaml.DocumentNode, Content: []*yaml.Node{in}})
+	bytes, _ := yaml.Marshal(in)
+
+	return bytes
+}
+
+func clearStyle(node *yaml.Node) {
+	node.Style = 0
+	for _, c := range node.Content {
+		clearStyle(c)
+	}
+}

vendor/github.com/google/gnostic-models/compiler/main.go

@@ -0,0 +1,16 @@
+// Copyright 2017 Google LLC. All Rights Reserved.
+//
+// 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 compiler provides support functions to generated compiler code.
+package compiler

vendor/github.com/google/gnostic-models/compiler/reader.go

@@ -0,0 +1,307 @@
+// Copyright 2017 Google LLC. All Rights Reserved.
+//
+// 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 compiler
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/url"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+var verboseReader = false
+
+var fileCache map[string][]byte
+var infoCache map[string]*yaml.Node
+
+var fileCacheEnable = true
+var infoCacheEnable = true
+
+// These locks are used to synchronize accesses to the fileCache and infoCache
+// maps (above). They are global state and can throw thread-related errors
+// when modified from separate goroutines. The general strategy is to protect
+// all public functions in this file with mutex Lock() calls. As a result, to
+// avoid deadlock, these public functions should not call other public
+// functions, so some public functions have private equivalents.
+// In the future, we might consider replacing the maps with sync.Map and
+// eliminating these mutexes.
+var fileCacheMutex sync.Mutex
+var infoCacheMutex sync.Mutex
+
+func initializeFileCache() {
+	if fileCache == nil {
+		fileCache = make(map[string][]byte, 0)
+	}
+}
+
+func initializeInfoCache() {
+	if infoCache == nil {
+		infoCache = make(map[string]*yaml.Node, 0)
+	}
+}
+
+// EnableFileCache turns on file caching.
+func EnableFileCache() {
+	fileCacheMutex.Lock()
+	defer fileCacheMutex.Unlock()
+	fileCacheEnable = true
+}
+
+// EnableInfoCache turns on parsed info caching.
+func EnableInfoCache() {
+	infoCacheMutex.Lock()
+	defer infoCacheMutex.Unlock()
+	infoCacheEnable = true
+}
+
+// DisableFileCache turns off file caching.
+func DisableFileCache() {
+	fileCacheMutex.Lock()
+	defer fileCacheMutex.Unlock()
+	fileCacheEnable = false
+}
+
+// DisableInfoCache turns off parsed info caching.
+func DisableInfoCache() {
+	infoCacheMutex.Lock()
+	defer infoCacheMutex.Unlock()
+	infoCacheEnable = false
+}
+
+// RemoveFromFileCache removes an entry from the file cache.
+func RemoveFromFileCache(fileurl string) {
+	fileCacheMutex.Lock()
+	defer fileCacheMutex.Unlock()
+	if !fileCacheEnable {
+		return
+	}
+	initializeFileCache()
+	delete(fileCache, fileurl)
+}
+
+// RemoveFromInfoCache removes an entry from the info cache.
+func RemoveFromInfoCache(filename string) {
+	infoCacheMutex.Lock()
+	defer infoCacheMutex.Unlock()
+	if !infoCacheEnable {
+		return
+	}
+	initializeInfoCache()
+	delete(infoCache, filename)
+}
+
+// GetInfoCache returns the info cache map.
+func GetInfoCache() map[string]*yaml.Node {
+	infoCacheMutex.Lock()
+	defer infoCacheMutex.Unlock()
+	if infoCache == nil {
+		initializeInfoCache()
+	}
+	return infoCache
+}
+
+// ClearFileCache clears the file cache.
+func ClearFileCache() {
+	fileCacheMutex.Lock()
+	defer fileCacheMutex.Unlock()
+	fileCache = make(map[string][]byte, 0)
+}
+
+// ClearInfoCache clears the info cache.
+func ClearInfoCache() {
+	infoCacheMutex.Lock()
+	defer infoCacheMutex.Unlock()
+	infoCache = make(map[string]*yaml.Node)
+}
+
+// ClearCaches clears all caches.
+func ClearCaches() {
+	ClearFileCache()
+	ClearInfoCache()
+}
+
+// FetchFile gets a specified file from the local filesystem or a remote location.
+func FetchFile(fileurl string) ([]byte, error) {
+	fileCacheMutex.Lock()
+	defer fileCacheMutex.Unlock()
+	return fetchFile(fileurl)
+}
+
+func fetchFile(fileurl string) ([]byte, error) {
+	var bytes []byte
+	initializeFileCache()
+	if fileCacheEnable {
+		bytes, ok := fileCache[fileurl]
+		if ok {
+			if verboseReader {
+				log.Printf("Cache hit %s", fileurl)
+			}
+			return bytes, nil
+		}
+		if verboseReader {
+			log.Printf("Fetching %s", fileurl)
+		}
+	}
+	response, err := http.Get(fileurl)
+	if err != nil {
+		return nil, err
+	}
+	defer response.Body.Close()
+	if response.StatusCode != 200 {
+		return nil, fmt.Errorf("Error downloading %s: %s", fileurl, response.Status)
+	}
+	bytes, err = ioutil.ReadAll(response.Body)
+	if fileCacheEnable && err == nil {
+		fileCache[fileurl] = bytes
+	}
+	return bytes, err
+}
+
+// ReadBytesForFile reads the bytes of a file.
+func ReadBytesForFile(filename string) ([]byte, error) {
+	fileCacheMutex.Lock()
+	defer fileCacheMutex.Unlock()
+	return readBytesForFile(filename)
+}
+
+func readBytesForFile(filename string) ([]byte, error) {
+	// is the filename a url?
+	fileurl, _ := url.Parse(filename)
+	if fileurl.Scheme != "" {
+		// yes, fetch it
+		bytes, err := fetchFile(filename)
+		if err != nil {
+			return nil, err
+		}
+		return bytes, nil
+	}
+	// no, it's a local filename
+	bytes, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return bytes, nil
+}
+
+// ReadInfoFromBytes unmarshals a file as a *yaml.Node.
+func ReadInfoFromBytes(filename string, bytes []byte) (*yaml.Node, error) {
+	infoCacheMutex.Lock()
+	defer infoCacheMutex.Unlock()
+	return readInfoFromBytes(filename, bytes)
+}
+
+func readInfoFromBytes(filename string, bytes []byte) (*yaml.Node, error) {
+	initializeInfoCache()
+	if infoCacheEnable {
+		cachedInfo, ok := infoCache[filename]
+		if ok {
+			if verboseReader {
+				log.Printf("Cache hit info for file %s", filename)
+			}
+			return cachedInfo, nil
+		}
+		if verboseReader {
+			log.Printf("Reading info for file %s", filename)
+		}
+	}
+	var info yaml.Node
+	err := yaml.Unmarshal(bytes, &info)
+	if err != nil {
+		return nil, err
+	}
+	if infoCacheEnable && len(filename) > 0 {
+		infoCache[filename] = &info
+	}
+	return &info, nil
+}
+
+// ReadInfoForRef reads a file and return the fragment needed to resolve a $ref.
+func ReadInfoForRef(basefile string, ref string) (*yaml.Node, error) {
+	fileCacheMutex.Lock()
+	defer fileCacheMutex.Unlock()
+	infoCacheMutex.Lock()
+	defer infoCacheMutex.Unlock()
+	initializeInfoCache()
+	if infoCacheEnable {
+		info, ok := infoCache[ref]
+		if ok {
+			if verboseReader {
+				log.Printf("Cache hit for ref %s#%s", basefile, ref)
+			}
+			return info, nil
+		}
+		if verboseReader {
+			log.Printf("Reading info for ref %s#%s", basefile, ref)
+		}
+	}
+	basedir, _ := filepath.Split(basefile)
+	parts := strings.Split(ref, "#")
+	var filename string
+	if parts[0] != "" {
+		filename = parts[0]
+		if _, err := url.ParseRequestURI(parts[0]); err != nil {
+			// It is not an URL, so the file is local
+			filename = basedir + parts[0]
+		}
+	} else {
+		filename = basefile
+	}
+	bytes, err := readBytesForFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	info, err := readInfoFromBytes(filename, bytes)
+	if info != nil && info.Kind == yaml.DocumentNode {
+		info = info.Content[0]
+	}
+	if err != nil {
+		log.Printf("File error: %v\n", err)
+	} else {
+		if info == nil {
+			return nil, NewError(nil, fmt.Sprintf("could not resolve %s", ref))
+		}
+		if len(parts) > 1 {
+			path := strings.Split(parts[1], "/")
+			for i, key := range path {
+				if i > 0 {
+					m := info
+					if true {
+						found := false
+						for i := 0; i < len(m.Content); i += 2 {
+							if m.Content[i].Value == key {
+								info = m.Content[i+1]
+								found = true
+							}
+						}
+						if !found {
+							infoCache[ref] = nil
+							return nil, NewError(nil, fmt.Sprintf("could not resolve %s", ref))
+						}
+					}
+				}
+			}
+		}
+	}
+	if infoCacheEnable {
+		infoCache[ref] = info
+	}
+	return info, nil
+}