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目前刚开始写一个月，一共写了18篇原创文章，文章目录如下：
istio防故障利器，你知道几个,istio新手不要读，太难！
不懂envoyfilter也敢说精通istio系列-http-rbac-不要只会用AuthorizationPolicy配置权限
不懂envoyfilter也敢说精通istio系列-02-http-corsFilter-不要只会vs
不懂envoyfilter也敢说精通istio系列-03-http-csrf filter-再也不用再代码里写csrf逻辑了
不懂envoyfilter也敢说精通istio系列http-jwt_authn-不要只会RequestAuthorization
不懂envoyfilter也敢说精通istio系列-05-fault-filter-故障注入不止是vs
不懂envoyfilter也敢说精通istio系列-06-http-match-配置路由不只是vs
不懂envoyfilter也敢说精通istio系列-07-负载均衡配置不止是dr
不懂envoyfilter也敢说精通istio系列-08-连接池和断路器
不懂envoyfilter也敢说精通istio系列-09-http-route filter
不懂envoyfilter也敢说精通istio系列-network filter-redis proxy
不懂envoyfilter也敢说精通istio系列-network filter-HttpConnectionManager
不懂envoyfilter也敢说精通istio系列-ratelimit-istio ratelimit完全手册
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type LabelOptions struct {//label结构体
// Filename options
resource.FilenameOptions
RecordFlags *genericclioptions.RecordFlags
PrintFlags *genericclioptions.PrintFlags
ToPrinter func(string) (printers.ResourcePrinter, error)
// Common user flags
overwrite bool
list bool
local bool
dryrun bool
all bool
resourceVersion string
selector string
fieldSelector string
outputFormat string
// results of arg parsing
resources []string
newLabels map[string]string
removeLabels []string
Recorder genericclioptions.Recorder
namespace string
enforceNamespace bool
builder *resource.Builder
unstructuredClientForMapping func(mapping *meta.RESTMapping) (resource.RESTClient, error)
// Common shared fields
genericclioptions.IOStreams
}func NewLabelOptions(ioStreams genericclioptions.IOStreams) *LabelOptions {
return &LabelOptions{//初始化结构体
RecordFlags: genericclioptions.NewRecordFlags(),
Recorder: genericclioptions.NoopRecorder{},
PrintFlags: genericclioptions.NewPrintFlags("labeled").WithTypeSetter(scheme.Scheme),
IOStreams: ioStreams,
}
}//创建label命令
func NewCmdLabel(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *cobra.Command {
o := NewLabelOptions(ioStreams)//初始化结构体
cmd := &cobra.Command{//创建cobra命令
Use: "label [--overwrite] (-f FILENAME | TYPE NAME) KEY_1=VAL_1 ... KEY_N=VAL_N [--resource-version=version]",
DisableFlagsInUseLine: true,
Short: i18n.T("Update the labels on a resource"),
Long: fmt.Sprintf(labelLong, validation.LabelValueMaxLength),
Example: labelExample,
Run: func(cmd *cobra.Command, args []string) {
cmdutil.CheckErr(o.Complete(f, cmd, args))//准备
cmdutil.CheckErr(o.Validate())//校验
cmdutil.CheckErr(o.RunLabel())//运行
},
}
o.RecordFlags.AddFlags(cmd)//record选项
o.PrintFlags.AddFlags(cmd)//打印选项
cmd.Flags().BoolVar(&o.overwrite, "overwrite", o.overwrite, "If true, allow labels to be overwritten, otherwise reject label updates that overwrite existing labels.")//overwrite选项
cmd.Flags().BoolVar(&o.list, "list", o.list, "If true, display the labels for a given resource.")//list选项
cmd.Flags().BoolVar(&o.local, "local", o.local, "If true, label will NOT contact api-server but run locally.")//local选项
cmd.Flags().StringVarP(&o.selector, "selector", "l", o.selector, "Selector (label query) to filter on, not including uninitialized ones, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2).")//selector选项
cmd.Flags().StringVar(&o.fieldSelector, "field-selector", o.fieldSelector, "Selector (field query) to filter on, supports '=', '==', and '!='.(e.g. --field-selector key1=value1,key2=value2). The server only supports a limited number of field queries per type.")//fieldSelector选项
cmd.Flags().BoolVar(&o.all, "all", o.all, "Select all resources, including uninitialized ones, in the namespace of the specified resource types")//all选项
cmd.Flags().StringVar(&o.resourceVersion, "resource-version", o.resourceVersion, i18n.T("If non-empty, the labels update will only succeed if this is the current resource-version for the object. Only valid when specifying a single resource."))//resource-version选项
usage := "identifying the resource to update the labels"
cmdutil.AddFilenameOptionFlags(cmd, &o.FilenameOptions, usage)//文件选项
cmdutil.AddDryRunFlag(cmd)//干跑选项
cmdutil.AddIncludeUninitializedFlag(cmd)
return cmd
}//准备
func (o *LabelOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
var err error
o.RecordFlags.Complete(cmd)//record complete
o.Recorder, err = o.RecordFlags.ToRecorder()//record flag转recorder
if err != nil {
return err
}
o.outputFormat = cmdutil.GetFlagString(cmd, "output")//输出格式
o.dryrun = cmdutil.GetDryRunFlag(cmd)//设置干跑
o.ToPrinter = func(operation string) (printers.ResourcePrinter, error) {//printflag转printer函数
o.PrintFlags.NamePrintFlags.Operation = operation
if o.dryrun {
o.PrintFlags.Complete("%s (dry run)")
}
return o.PrintFlags.ToPrinter()
}
resources, labelArgs, err := cmdutil.GetResourcesAndPairs(args, "label")//抽取resrouce和label参数
if err != nil {
return err
}
o.resources = resources
o.newLabels, o.removeLabels, err = parseLabels(labelArgs)//解析lable参数
if o.list && len(o.outputFormat) > 0 {//不能同时指定list和output
return fmt.Errorf("--list and --output may not be specified together")
}
o.namespace, o.enforceNamespace, err = f.ToRawKubeConfigLoader().Namespace()//设置namespace和EnforceNamespace
if err != nil {
return err
}
o.builder = f.NewBuilder()//设置builder
o.unstructuredClientForMapping = f.UnstructuredClientForMapping//设置unstructuredClientForMapping
return nil
}//校验
func (o *LabelOptions) Validate() error {
if o.all && len(o.selector) > 0 {//all和selector不能同时指定
return fmt.Errorf("cannot set --all and --selector at the same time")
}
if o.all && len(o.fieldSelector) > 0 {//all和field-selector不能同时指定
return fmt.Errorf("cannot set --all and --field-selector at the same time")
}
if len(o.resources) < 1 && cmdutil.IsFilenameSliceEmpty(o.FilenameOptions.Filenames, o.FilenameOptions.Kustomize) {//资源和文件不能同时为空
return fmt.Errorf("one or more resources must be specified as <resource> <name> or <resource>/<name>")
}
if len(o.newLabels) < 1 && len(o.removeLabels) < 1 && !o.list {//list和创建，删除label不能同时为空
return fmt.Errorf("at least one label update is required")
}
return nil
}func (o *LabelOptions) RunLabel() error {
b := o.builder.
Unstructured().
LocalParam(o.local).
ContinueOnError().
NamespaceParam(o.namespace).DefaultNamespace().
FilenameParam(o.enforceNamespace, &o.FilenameOptions).
Flatten()//用build构造result对象
if !o.local {
b = b.LabelSelectorParam(o.selector).
FieldSelectorParam(o.fieldSelector).
ResourceTypeOrNameArgs(o.all, o.resources...).
Latest()
}
one := false
r := b.Do().IntoSingleItemImplied(&one)
if err := r.Err(); err != nil {
return err
}
// only apply resource version locking on a single resource
if !one && len(o.resourceVersion) > 0 {//如果info不止一个，并指定了resource-version报错
return fmt.Errorf("--resource-version may only be used with a single resource")
}
// TODO: support bulk generic output a la Get
return r.Visit(func(info *resource.Info, err error) error {// visit result
if err != nil {
return err
}
var outputObj runtime.Object
var dataChangeMsg string
obj := info.Object//获取info object
oldData, err := json.Marshal(obj)//把obj转成json
if err != nil {
return err
}
if o.dryrun || o.local || o.list {// 如果是干跑，local，或list
err = labelFunc(obj, o.overwrite, o.resourceVersion, o.newLabels, o.removeLabels)//给对象打标签
if err != nil {
return err
}
newObj, err := json.Marshal(obj)//把打过标签的对象转成json
if err != nil {
return err
}
dataChangeMsg = updateDataChangeMsg(oldData, newObj)//判断是否有更改
outputObj = info.Object//设置outputObj
} else {
name, namespace := info.Name, info.Namespace//获取名称和名称空间
if err != nil {
return err
}
accessor, err := meta.Accessor(obj)//访问对象
if err != nil {
return err
}
for _, label := range o.removeLabels {// 遍历要删除的labels
if _, ok := accessor.GetLabels()[label]; !ok {//如果要删除的label不存在则打印提示
fmt.Fprintf(o.Out, "label %q not found.\n", label)
}
}
if err := labelFunc(obj, o.overwrite, o.resourceVersion, o.newLabels, o.removeLabels); err != nil {// 给对象打标签
return err
}
if err := o.Recorder.Record(obj); err != nil {//判断是否创建change-cause注解
klog.V(4).Infof("error recording current command: %v", err)
}
newObj, err := json.Marshal(obj)//吧对象转json
if err != nil {
return err
}
dataChangeMsg = updateDataChangeMsg(oldData, newObj)// 判断是否有更改
patchBytes, err := jsonpatch.CreateMergePatch(oldData, newObj)//创建patch
createdPatch := err == nil
if err != nil {
klog.V(2).Infof("couldn't compute patch: %v", err)
}
mapping := info.ResourceMapping()// 获取mapping
client, err := o.unstructuredClientForMapping(mapping)// 获取client
if err != nil {
return err
}
helper := resource.NewHelper(client, mapping)//构造helper
if createdPatch {//应用patch到服务端
outputObj, err = helper.Patch(namespace, name, types.MergePatchType, patchBytes, nil)
} else {// replace obj到服务端
outputObj, err = helper.Replace(namespace, name, false, obj)
}
if err != nil {
return err
}
}
if o.list {//如果指定了list
accessor, err := meta.Accessor(outputObj)//访问要输出的对象
if err != nil {
return err
}
indent := ""
if !one {//如果是多个对象
indent = " "
gvks, _, err := unstructuredscheme.NewUnstructuredObjectTyper().ObjectKinds(info.Object)//获取gvk
if err != nil {
return err
}
fmt.Fprintf(o.ErrOut, "Listing labels for %s.%s/%s:\n", gvks[0].Kind, gvks[0].Group, info.Name)//打印提示
}
for k, v := range accessor.GetLabels() {//遍历labels，输出
fmt.Fprintf(o.Out, "%s%s=%s\n", indent, k, v)
}
return nil
}
printer, err := o.ToPrinter(dataChangeMsg)//printflag转printer
if err != nil {
return err
}
return printer.PrintObj(info.Object, o.Out)//打印对象
})
}//给对象打标签
func labelFunc(obj runtime.Object, overwrite bool, resourceVersion string, labels map[string]string, remove []string) error {
accessor, err := meta.Accessor(obj)//访问对象
if err != nil {
return err
}
if !overwrite {// 如果没有指定overwrite
if err := validateNoOverwrites(accessor, labels); err != nil {//判断标签是否冲突
return err
}
}
objLabels := accessor.GetLabels()//获取对象labels
if objLabels == nil {
objLabels = make(map[string]string)
}
for key, value := range labels {//遍历要添加的标签，依次添加
objLabels[key] = value
}
for _, label := range remove {//遍历要删除的labels，依次删除
delete(objLabels, label)
}
accessor.SetLabels(objLabels)//设置对象的labels
if len(resourceVersion) != 0 {// 如果resource-version不为空，设置resource-version
accessor.SetResourceVersion(resourceVersion)
}
return nil
}func updateDataChangeMsg(oldObj []byte, newObj []byte) string {//判断是否有更新，返回提示字符串
msg := "not labeled"
if !reflect.DeepEqual(oldObj, newObj) {
msg = "labeled"
}
return msg
}
func validateNoOverwrites(accessor metav1.Object, labels map[string]string) error {
allErrs := []error{}
for key := range labels {//遍历要添加的labels
if value, found := accessor.GetLabels()[key]; found {//如果label存在，则报错
allErrs = append(allErrs, fmt.Errorf("'%s' already has a value (%s), and --overwrite is false", key, value))
}
}
return utilerrors.NewAggregate(allErrs)
}
//解析labels
func parseLabels(spec []string) (map[string]string, []string, error) {
labels := map[string]string{}
var remove []string
for _, labelSpec := range spec {//遍历
if strings.Contains(labelSpec, "=") {//如果参数有=号
parts := strings.Split(labelSpec, "=")//用等号分割
if len(parts) != 2 {// 如果分割后不是两个，报错
return nil, nil, fmt.Errorf("invalid label spec: %v", labelSpec)
}
if errs := validation.IsValidLabelValue(parts[1]); len(errs) != 0 {//判断label是否有效字符串
return nil, nil, fmt.Errorf("invalid label value: %q: %s", labelSpec, strings.Join(errs, ";"))
}
labels[parts[0]] = parts[1]//把label放到map
} else if strings.HasSuffix(labelSpec, "-") {//如果label末尾有-
remove = append(remove, labelSpec[:len(labelSpec)-1])//添加label到remove slice
} else {//否则返回错误
return nil, nil, fmt.Errorf("unknown label spec: %v", labelSpec)
}
}
for _, removeLabel := range remove {//遍历remove slice
if _, found := labels[removeLabel]; found {//如果label map里有removelabel则报错
return nil, nil, fmt.Errorf("can not both modify and remove a label in the same command")
}
}
return labels, remove, nil
}
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