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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 SetSelectorOptions struct {//set selector结构体
    // Bound
    ResourceBuilderFlags *genericclioptions.ResourceBuilderFlags
    PrintFlags           *genericclioptions.PrintFlags
    RecordFlags          *genericclioptions.RecordFlags
    dryrun               bool
    // set by args
    resources []string
    selector  *metav1.LabelSelector
    // computed
    WriteToServer  bool
    PrintObj       printers.ResourcePrinterFunc
    Recorder       genericclioptions.Recorder
    ResourceFinder genericclioptions.ResourceFinder
    // set at initialization
    genericclioptions.IOStreams
}
func NewSelectorOptions(streams genericclioptions.IOStreams) *SetSelectorOptions {
    return &SetSelectorOptions{//初始化结构体
        ResourceBuilderFlags: genericclioptions.NewResourceBuilderFlags().
            WithScheme(scheme.Scheme).
            WithAll(false).
            WithLocal(false).
            WithLatest(),
        PrintFlags:  genericclioptions.NewPrintFlags("selector updated").WithTypeSetter(scheme.Scheme),
        RecordFlags: genericclioptions.NewRecordFlags(),
        Recorder: genericclioptions.NoopRecorder{},
        IOStreams: streams,
    }
}
//创建set selector命令
func NewCmdSelector(f cmdutil.Factory, streams genericclioptions.IOStreams) *cobra.Command {
    o := NewSelectorOptions(streams)//初始化结构体
    cmd := &cobra.Command{//创建cobra命令
        Use:                   "selector (-f FILENAME | TYPE NAME) EXPRESSIONS [--resource-version=version]",
        DisableFlagsInUseLine: true,
        Short:                 i18n.T("Set the selector on a resource"),
        Long:                  fmt.Sprintf(selectorLong, validation.LabelValueMaxLength),
        Example:               selectorExample,
        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.RunSelector())//运行
        },
    }
    o.ResourceBuilderFlags.AddFlags(cmd.Flags())//构造资源flag
    o.PrintFlags.AddFlags(cmd)//设置打印flag
    o.RecordFlags.AddFlags(cmd)//设置record选项
    cmd.Flags().String("resource-version", "", "If non-empty, the selectors update will only succeed if this is the current resource-version for the object. Only valid when specifying a single resource.")//设置resource version选项
    cmdutil.AddDryRunFlag(cmd)//设置干跑选项
    return cmd
}
//准备函数
func (o *SetSelectorOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
    var err error
    o.RecordFlags.Complete(cmd)//record flag complete
    o.Recorder, err = o.RecordFlags.ToRecorder()//record flag转recorder
    if err != nil {
        return err
    }
    o.dryrun = cmdutil.GetDryRunFlag(cmd)//设置干跑
    o.resources, o.selector, err = getResourcesAndSelector(args)//设置resource和selector
    if err != nil {
        return err
    }
    o.ResourceFinder = o.ResourceBuilderFlags.ToBuilder(f, o.resources)//设置resorucebuilder
    o.WriteToServer = !(*o.ResourceBuilderFlags.Local || o.dryrun)//判断是否写到服务器
    if o.dryrun {
        o.PrintFlags.Complete("%s (dry run)")
    }
    printer, err := o.PrintFlags.ToPrinter()//打印选项转printer
    if err != nil {
        return err
    }
    o.PrintObj = printer.PrintObj//设置printObj函数
    return err
}
func (o *SetSelectorOptions) Validate() error {
    if o.selector == nil {//selector不能为空
        return fmt.Errorf("one selector is required")
    }
    return nil
}
//运行
func (o *SetSelectorOptions) RunSelector() error {
    r := o.ResourceFinder.Do()//从builder获取result
    return r.Visit(func(info *resource.Info, err error) error {//访问result
        patch := &Patch{Info: info}//构造patch
        CalculatePatch(patch, scheme.DefaultJSONEncoder(), func(obj runtime.Object) ([]byte, error) {//计算patch
            selectErr := updateSelectorForObject(info.Object, *o.selector)//更新对象selector
            if selectErr != nil {
                return nil, selectErr
            }
            // record this change (for rollout history)
            if err := o.Recorder.Record(patch.Info.Object); err != nil {//判断是否更新change-cause注解
                klog.V(4).Infof("error recording current command: %v", err)
            }
            return runtime.Encode(scheme.DefaultJSONEncoder(), info.Object)//obj转json
        })
        if patch.Err != nil {
            return patch.Err
        }
        if !o.WriteToServer {//如果不写到服务器则打印
            return o.PrintObj(info.Object, o.Out)
        }
        actual, err := resource.NewHelper(info.Client, info.Mapping).Patch(info.Namespace, info.Name, types.StrategicMergePatchType, patch.Patch, nil)//应用patch到服务器
        if err != nil {
            return err
        }
        return o.PrintObj(actual, o.Out)//打印对象
    })
}
//更新对象selector
func updateSelectorForObject(obj runtime.Object, selector metav1.LabelSelector) error {
    copyOldSelector := func() (map[string]string, error) {//获取selector
        if len(selector.MatchExpressions) > 0 {//不支持matchExpression
            return nil, fmt.Errorf("match expression %v not supported on this object", selector.MatchExpressions)
        }
        dst := make(map[string]string)
        for label, value := range selector.MatchLabels {//遍历matchLabels
            dst[label] = value//设置labels map
        }
        return dst, nil//返回labels map
    }
    var err error
    switch t := obj.(type) {//判断对象
    case *v1.Service://如果是service
        t.Spec.Selector, err = copyOldSelector()//设置selector
    default:
        err = fmt.Errorf("setting a selector is only supported for Services")
    }
    return err
}