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richabankerk8s-publishing-bot
richabanker
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Add flagz implementation and enablement in apiserver
Kubernetes-commit: da8dc433e9b5fb29f3cc91f79ed15f366addefd1
1 parent 35b7478 commit aa5f70d

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5 files changed

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-0
lines changed

5 files changed

+406
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lines changed

‎zpages/features/kube_features.go

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@@ -22,6 +22,10 @@ import (
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)
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const (
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// owner: @richabanker
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// kep: https://kep.k8s.io/4828
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ComponentFlagz featuregate.Feature = "ComponentFlagz"
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// owner: @richabanker
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// kep: https://kep.k8s.io/4827
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// alpha: v1.32
@@ -33,6 +37,9 @@ const (
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func featureGates() map[featuregate.Feature]featuregate.VersionedSpecs {
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return map[featuregate.Feature]featuregate.VersionedSpecs{
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ComponentFlagz: {
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{Version: version.MustParse("1.32"), Default: false, PreRelease: featuregate.Alpha},
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},
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ComponentStatusz: {
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{Version: version.MustParse("1.32"), Default: false, PreRelease: featuregate.Alpha},
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},

‎zpages/flagz/flagreader.go

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/*
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Copyright 2024 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package flagz
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import (
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"github.com/spf13/pflag"
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cliflag "k8s.io/component-base/cli/flag"
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)
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type Reader interface {
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GetFlagz() map[string]string
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}
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// NamedFlagSetsGetter implements Reader for cliflag.NamedFlagSets
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type NamedFlagSetsReader struct {
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FlagSets cliflag.NamedFlagSets
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}
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func (n NamedFlagSetsReader) GetFlagz() map[string]string {
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return convertNamedFlagSetToFlags(&n.FlagSets)
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}
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func convertNamedFlagSetToFlags(flagSets *cliflag.NamedFlagSets) map[string]string {
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flags := make(map[string]string)
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for _, fs := range flagSets.FlagSets {
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fs.VisitAll(func(flag *pflag.Flag) {
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if flag.Value != nil {
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value := flag.Value.String()
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if set, ok := flag.Annotations["classified"]; ok && len(set) > 0 {
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value = "CLASSIFIED"
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}
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flags[flag.Name] = value
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}
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})
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}
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return flags
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}

‎zpages/flagz/flagreader_test.go

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/*
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Copyright 2024 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package flagz
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import (
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"reflect"
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"testing"
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"github.com/spf13/pflag"
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"k8s.io/component-base/cli/flag"
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)
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func TestConvertNamedFlagSetToFlags(t *testing.T) {
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tests := []struct {
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name string
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flagSets *flag.NamedFlagSets
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want map[string]string
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}{
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{
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name: "basic flags",
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flagSets: &flag.NamedFlagSets{
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FlagSets: map[string]*pflag.FlagSet{
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"test": flagSet(t, map[string]flagValue{
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"flag1": {value: "value1", sensitive: false},
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"flag2": {value: "value2", sensitive: false},
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}),
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},
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},
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want: map[string]string{
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"flag1": "value1",
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"flag2": "value2",
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},
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},
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{
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name: "classified flags",
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flagSets: &flag.NamedFlagSets{
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FlagSets: map[string]*pflag.FlagSet{
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"test": flagSet(t, map[string]flagValue{
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"secret1": {value: "value1", sensitive: true},
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"flag2": {value: "value2", sensitive: false},
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}),
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},
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},
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want: map[string]string{
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"flag2": "value2",
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"secret1": "CLASSIFIED",
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},
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},
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}
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for _, tt := range tests {
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t.Run(tt.name, func(t *testing.T) {
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got := convertNamedFlagSetToFlags(tt.flagSets)
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if !reflect.DeepEqual(got, tt.want) {
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t.Errorf("ConvertNamedFlagSetToFlags() = %v, want %v", got, tt.want)
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}
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})
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}
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}
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type flagValue struct {
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value string
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sensitive bool
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}
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func flagSet(t *testing.T, flags map[string]flagValue) *pflag.FlagSet {
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fs := pflag.NewFlagSet("test-set", pflag.ContinueOnError)
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for flagName, flagVal := range flags {
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flagValue := ""
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fs.StringVar(&flagValue, flagName, flagVal.value, "test-usage")
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if flagVal.sensitive {
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err := fs.SetAnnotation(flagName, "classified", []string{"true"})
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if err != nil {
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t.Fatalf("unexpected error when setting flag annotation: %v", err)
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}
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}
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}
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return fs
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}

‎zpages/flagz/flagz.go

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/*
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Copyright 2024 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
11+
distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package flagz
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import (
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"bytes"
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"fmt"
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"io"
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"math/rand"
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"net/http"
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"sort"
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"strings"
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"sync"
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"github.com/munnerz/goautoneg"
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"k8s.io/klog/v2"
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)
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const (
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flagzHeaderFmt = `
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%s flags
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Warning: This endpoint is not meant to be machine parseable, has no formatting compatibility guarantees and is for debugging purposes only.
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`
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)
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var (
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flagzSeparators = []string{":", ": ", "=", " "}
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errUnsupportedMediaType = fmt.Errorf("media type not acceptable, must be: text/plain")
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)
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type registry struct {
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response bytes.Buffer
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once sync.Once
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}
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type mux interface {
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Handle(path string, handler http.Handler)
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}
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func Install(m mux, componentName string, flagReader Reader) {
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var reg registry
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reg.installHandler(m, componentName, flagReader)
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}
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func (reg *registry) installHandler(m mux, componentName string, flagReader Reader) {
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m.Handle("/flagz", reg.handleFlags(componentName, flagReader))
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}
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func (reg *registry) handleFlags(componentName string, flagReader Reader) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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if !acceptableMediaType(r) {
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http.Error(w, errUnsupportedMediaType.Error(), http.StatusNotAcceptable)
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return
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}
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reg.once.Do(func() {
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fmt.Fprintf(&reg.response, flagzHeaderFmt, componentName)
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if flagReader == nil {
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klog.Error("received nil flagReader")
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return
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}
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randomIndex := rand.Intn(len(flagzSeparators))
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separator := flagzSeparators[randomIndex]
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// Randomize the delimiter for printing to prevent scraping of the response.
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printSortedFlags(&reg.response, flagReader.GetFlagz(), separator)
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})
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w.Header().Set("Content-Type", "text/plain; charset=utf-8")
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_, err := w.Write(reg.response.Bytes())
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if err != nil {
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klog.Errorf("error writing response: %v", err)
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http.Error(w, "error writing response", http.StatusInternalServerError)
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}
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}
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}
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func acceptableMediaType(r *http.Request) bool {
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accepts := goautoneg.ParseAccept(r.Header.Get("Accept"))
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for _, accept := range accepts {
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if !mediaTypeMatches(accept) {
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continue
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}
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if len(accept.Params) == 0 {
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return true
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}
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if len(accept.Params) == 1 {
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if charset, ok := accept.Params["charset"]; ok && strings.EqualFold(charset, "utf-8") {
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return true
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}
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}
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}
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return false
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}
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func mediaTypeMatches(a goautoneg.Accept) bool {
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return (a.Type == "text" || a.Type == "*") &&
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(a.SubType == "plain" || a.SubType == "*")
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}
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func printSortedFlags(w io.Writer, flags map[string]string, separator string) {
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var sortedKeys []string
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for key := range flags {
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sortedKeys = append(sortedKeys, key)
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}
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sort.Strings(sortedKeys)
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for _, key := range sortedKeys {
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fmt.Fprintf(w, "%s%s%s\n", key, separator, flags[key])
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}
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}

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