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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多集群探秘，部署了50次多集群后我得出的结论

istio多集群链路追踪，附实操视频

istio防故障利器，你知道几个,istio新手不要读，太难！

istio业务权限控制，原来可以这么玩

istio实现非侵入压缩，微服务之间如何实现压缩

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 PatchOptions struct {//patch结构体resource.FilenameOptionsRecordFlags *genericclioptions.RecordFlagsPrintFlags  *genericclioptions.PrintFlagsToPrinter   func(string) (printers.ResourcePrinter, error)Recorder    genericclioptions.RecorderLocal     boolPatchType stringPatch     stringnamespace                    stringenforceNamespace             booldryRun                       booloutputFormat                 stringargs                         []stringbuilder                      *resource.BuilderunstructuredClientForMapping func(mapping *meta.RESTMapping) (resource.RESTClient, error)genericclioptions.IOStreams
}

func NewPatchOptions(ioStreams genericclioptions.IOStreams) *PatchOptions {return &PatchOptions{//初始化patch结构体RecordFlags: genericclioptions.NewRecordFlags(),Recorder:    genericclioptions.NoopRecorder{},PrintFlags:  genericclioptions.NewPrintFlags("patched").WithTypeSetter(scheme.Scheme),IOStreams:   ioStreams,}
}

//创建patch命令
func NewCmdPatch(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *cobra.Command {o := NewPatchOptions(ioStreams)//初始化结构体cmd := &cobra.Command{//创建cobra命令Use:                   "patch (-f FILENAME | TYPE NAME) -p PATCH",DisableFlagsInUseLine: true,Short:                 i18n.T("Update field(s) of a resource using strategic merge patch"),Long:                  patchLong,Example:               patchExample,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.RunPatch())//运行},}o.RecordFlags.AddFlags(cmd)//record选项o.PrintFlags.AddFlags(cmd)//打印选项cmd.Flags().StringVarP(&o.Patch, "patch", "p", "", "The patch to be applied to the resource JSON file.")//patch选项cmd.MarkFlagRequired("patch")//必须cmd.Flags().StringVar(&o.PatchType, "type", "strategic", fmt.Sprintf("The type of patch being provided; one of %v", sets.StringKeySet(patchTypes).List()))// type选项cmdutil.AddDryRunFlag(cmd)//干跑选项cmdutil.AddFilenameOptionFlags(cmd, &o.FilenameOptions, "identifying the resource to update")//文件选项cmd.Flags().BoolVar(&o.Local, "local", o.Local, "If true, patch will operate on the content of the file, not the server-side resource.")//local选项return cmd
}

//准备
func (o *PatchOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {var err erroro.RecordFlags.Complete(cmd)//record准备o.Recorder, err = o.RecordFlags.ToRecorder()//record flag转recorderif err != nil {return err}o.outputFormat = cmdutil.GetFlagString(cmd, "output")//设置输出选项o.dryRun = cmdutil.GetFlagBool(cmd, "dry-run")//设置干跑o.ToPrinter = func(operation string) (printers.ResourcePrinter, error) {//print flag转printer函数o.PrintFlags.NamePrintFlags.Operation = operationif o.dryRun {o.PrintFlags.Complete("%s (dry run)")}return o.PrintFlags.ToPrinter()}o.namespace, o.enforceNamespace, err = f.ToRawKubeConfigLoader().Namespace()//设置namespace和enforceNamespaceif err != nil {return err}o.args = args//设置参数o.builder = f.NewBuilder()//设置buildero.unstructuredClientForMapping = f.UnstructuredClientForMapping//设置unstructuredClientForMapping return nil
}

//校验
func (o *PatchOptions) Validate() error {if o.Local && len(o.args) != 0 {// 如果指定了local则参数必须为空return fmt.Errorf("cannot specify --local and server resources")}if len(o.Patch) == 0 {//patch选项不能为空return fmt.Errorf("must specify -p to patch")}if len(o.PatchType) != 0 {//patch类型必须正确if _, ok := patchTypes[strings.ToLower(o.PatchType)]; !ok {return fmt.Errorf("--type must be one of %v, not %q", sets.StringKeySet(patchTypes).List(), o.PatchType)}}return nil
}

///运行
func (o *PatchOptions) RunPatch() error {patchType := types.StrategicMergePatchType//设置patch类型if len(o.PatchType) != 0 {//如果指定了patch类型，则重新设置patchType = patchTypes[strings.ToLower(o.PatchType)]}patchBytes, err := yaml.ToJSON([]byte(o.Patch))//获取patch字节数组if err != nil {return fmt.Errorf("unable to parse %q: %v", o.Patch, err)}r := o.builder.Unstructured().ContinueOnError().LocalParam(o.Local).NamespaceParam(o.namespace).DefaultNamespace().FilenameParam(o.enforceNamespace, &o.FilenameOptions).ResourceTypeOrNameArgs(false, o.args...).Flatten().Do()//用build构造result对象err = r.Err()if err != nil {return err}count := 0err = r.Visit(func(info *resource.Info, err error) error {//visit resultif err != nil {return err}count++name, namespace := info.Name, info.Namespace//获取name和namespaceif !o.Local && !o.dryRun {//如果非local且非干跑mapping := info.ResourceMapping()//获取mappingclient, err := o.unstructuredClientForMapping(mapping)//通过mapping获取clientif err != nil {return err}helper := resource.NewHelper(client, mapping)//构造helperpatchedObj, err := helper.Patch(namespace, name, patchType, patchBytes, nil)//应用patch到服务端if err != nil {return err}didPatch := !reflect.DeepEqual(info.Object, patchedObj)//判断是否做了patch// if the recorder makes a change, compute and create another patchif mergePatch, err := o.Recorder.MakeRecordMergePatch(patchedObj); err != nil {//判断是否创建change-cause注解klog.V(4).Infof("error recording current command: %v", err)} else if len(mergePatch) > 0 {if recordedObj, err := helper.Patch(info.Namespace, info.Name, types.MergePatchType, mergePatch, nil); err != nil {//创建changecause注解klog.V(4).Infof("error recording reason: %v", err)} else {patchedObj = recordedObj}}printer, err := o.ToPrinter(patchOperation(didPatch))//print flag转peinterif err != nil {return err}return printer.PrintObj(patchedObj, o.Out)//打印对象}originalObjJS, err := runtime.Encode(unstructured.UnstructuredJSONScheme, info.Object)//原始的jsonif err != nil {return err}originalPatchedObjJS, err := getPatchedJSON(patchType, originalObjJS, patchBytes, info.Object.GetObjectKind().GroupVersionKind(), scheme.Scheme)//patch后的jsonif err != nil {return err}targetObj, err := runtime.Decode(unstructured.UnstructuredJSONScheme, originalPatchedObjJS)//patch后的对象if err != nil {return err}didPatch := !reflect.DeepEqual(info.Object, targetObj)//判断是否做了patchprinter, err := o.ToPrinter(patchOperation(didPatch))// print flag转printerif err != nil {return err}return printer.PrintObj(targetObj, o.Out)//打印对象})if err != nil {return err}if count == 0 {return fmt.Errorf("no objects passed to patch")}return nil
}

//获取patch后的json
func getPatchedJSON(patchType types.PatchType, originalJS, patchJS []byte, gvk schema.GroupVersionKind, creater runtime.ObjectCreater) ([]byte, error) {switch patchType {//switchpatch类型case types.JSONPatchType://如果时候jsonpatchObj, err := jsonpatch.DecodePatch(patchJS)//解码patch jsonif err != nil {return nil, err}bytes, err := patchObj.Apply(originalJS)//应用patch json// TODO: This is pretty hacky, we need a better structured error from the json-patchif err != nil && strings.Contains(err.Error(), "doc is missing key") {msg := err.Error()ix := strings.Index(msg, "key:")key := msg[ix+5:]return bytes, fmt.Errorf("Object to be patched is missing field (%s)", key)}return bytes, err//返回patch后的jsoncase types.MergePatchType://如果是mergereturn jsonpatch.MergePatch(originalJS, patchJS)//合并patch，返回jsoncase types.StrategicMergePatchType://如果是strategic// get a typed object for this GVK if we need to apply a strategic merge patchobj, err := creater.New(gvk)//创建对象if err != nil {return nil, fmt.Errorf("cannot apply strategic merge patch for %s locally, try --type merge", gvk.String())}return strategicpatch.StrategicMergePatch(originalJS, patchJS, obj)//合并patch，返回jsondefault:// only here as a safety net - go-restful filters content-typereturn nil, fmt.Errorf("unknown Content-Type header for patch: %v", patchType)}
}