kubectl源码分析之apply edit-last-applied

Love The Way You Lie 2023-02-19 15:23 38阅读 0赞

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![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAaHhwamF2YTE_size_8_color_FFFFFF_t_70_g_se_x_16][]

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_50]

[istio多集群链路追踪，附实操视频][istio]

[istio防故障利器，你知道几个,istio新手不要读，太难！][istio_istio]

[istio业务权限控制，原来可以这么玩][istio 1]

[istio实现非侵入压缩，微服务之间如何实现压缩][istio 2]

[不懂envoyfilter也敢说精通istio系列-http-rbac-不要只会用AuthorizationPolicy配置权限][envoyfilter_istio_-http-rbac-_AuthorizationPolicy]

[不懂envoyfilter也敢说精通istio系列-02-http-corsFilter-不要只会vs][envoyfilter_istio_-02-http-corsFilter-_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][envoyfilter_istio_-03-http-csrf filter-_csrf]

[不懂envoyfilter也敢说精通istio系列http-jwt\_authn-不要只会RequestAuthorization][envoyfilter_istio_http-jwt_authn-_RequestAuthorization]

[不懂envoyfilter也敢说精通istio系列-05-fault-filter-故障注入不止是vs][envoyfilter_istio_-05-fault-filter-_vs]

[不懂envoyfilter也敢说精通istio系列-06-http-match-配置路由不只是vs][envoyfilter_istio_-06-http-match-_vs]

[不懂envoyfilter也敢说精通istio系列-07-负载均衡配置不止是dr][envoyfilter_istio_-07-_dr]

[不懂envoyfilter也敢说精通istio系列-08-连接池和断路器][envoyfilter_istio_-08-]

[不懂envoyfilter也敢说精通istio系列-09-http-route filter][envoyfilter_istio_-09-http-route filter]

[不懂envoyfilter也敢说精通istio系列-network filter-redis proxy][envoyfilter_istio_-network filter-redis proxy]

[不懂envoyfilter也敢说精通istio系列-network filter-HttpConnectionManager][envoyfilter_istio_-network filter-HttpConnectionManager]

[不懂envoyfilter也敢说精通istio系列-ratelimit-istio ratelimit完全手册][envoyfilter_istio_-ratelimit-istio ratelimit]

————————————————

//创建edit-last-applied命令
    func NewCmdApplyEditLastApplied(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *cobra.Command {
    	o := editor.NewEditOptions(editor.ApplyEditMode, ioStreams)//初始化edit-option结构体
    
    	cmd := &cobra.Command{//创建cobra命令
    		Use:                   "edit-last-applied (RESOURCE/NAME | -f FILENAME)",
    		DisableFlagsInUseLine: true,
    		Short:                 "Edit latest last-applied-configuration annotations of a resource/object",
    		Long:                  applyEditLastAppliedLong,
    		Example:               applyEditLastAppliedExample,
    		Run: func(cmd *cobra.Command, args []string) {
    			if err := o.Complete(f, args, cmd); err != nil {//准备
    				cmdutil.CheckErr(err)
    			}
    			if err := o.Run(); err != nil {//运行
    				cmdutil.CheckErr(err)
    			}
    		},
    	}
    
    	// bind flag structs
    	o.RecordFlags.AddFlags(cmd)//record选项
    	o.PrintFlags.AddFlags(cmd)//打印选项
    
    	usage := "to use to edit the resource"
    	cmdutil.AddFilenameOptionFlags(cmd, &o.FilenameOptions, usage)//文件选项
    	cmd.Flags().BoolVar(&o.WindowsLineEndings, "windows-line-endings", o.WindowsLineEndings,
    		"Defaults to the line ending native to your platform.")//windows-line-endings选项
    	cmdutil.AddIncludeUninitializedFlag(cmd)
    
    	return cmd
    }

type EditOptions struct {//edit结构体
    	resource.FilenameOptions
    	RecordFlags *genericclioptions.RecordFlags
    
    	PrintFlags *genericclioptions.PrintFlags
    	ToPrinter  func(string) (printers.ResourcePrinter, error)
    
    	OutputPatch        bool
    	WindowsLineEndings bool
    
    	cmdutil.ValidateOptions
    
    	OriginalResult *resource.Result
    
    	EditMode EditMode
    
    	CmdNamespace    string
    	ApplyAnnotation bool
    	ChangeCause     string
    
    	genericclioptions.IOStreams
    
    	Recorder            genericclioptions.Recorder
    	f                   cmdutil.Factory
    	editPrinterOptions  *editPrinterOptions
    	updatedResultGetter func(data []byte) *resource.Result
    }

//准备
    func (o *EditOptions) Complete(f cmdutil.Factory, args []string, cmd *cobra.Command) error {
    	var err error
    
    	o.RecordFlags.Complete(cmd)//准备record
    	o.Recorder, err = o.RecordFlags.ToRecorder()//recordflag转recorder
    	if err != nil {
    		return err
    	}
    
    	if o.EditMode != NormalEditMode && o.EditMode != EditBeforeCreateMode && o.EditMode != ApplyEditMode {//判断editmode是否合法
    		return fmt.Errorf("unsupported edit mode %q", o.EditMode)
    	}
    
    	o.editPrinterOptions.Complete(o.PrintFlags)//准备print
    
    	if o.OutputPatch && o.EditMode != NormalEditMode {
    		return fmt.Errorf("the edit mode doesn't support output the patch")
    	}
    
    	cmdNamespace, enforceNamespace, err := f.ToRawKubeConfigLoader().Namespace()//获取namespace和enforceNamespace
    	if err != nil {
    		return err
    	}
    	b := f.NewBuilder().
    		Unstructured()
    	if o.EditMode == NormalEditMode || o.EditMode == ApplyEditMode {
    		// when do normal edit or apply edit we need to always retrieve the latest resource from server
    		b = b.ResourceTypeOrNameArgs(true, args...).Latest()
    	}
    	r := b.NamespaceParam(cmdNamespace).DefaultNamespace().
    		FilenameParam(enforceNamespace, &o.FilenameOptions).
    		ContinueOnError().
    		Flatten().
    		Do()//用builder构造result对象
    	err = r.Err()
    	if err != nil {
    		return err
    	}
    	o.OriginalResult = r//设置OriginalResult 
    
    	o.updatedResultGetter = func(data []byte) *resource.Result {//设置updatedResultGetter 函数
    		// resource builder to read objects from edited data
    		return f.NewBuilder().
    			Unstructured().
    			Stream(bytes.NewReader(data), "edited-file").
    			ContinueOnError().
    			Flatten().
    			Do()
    	}
    
    	o.ToPrinter = func(operation string) (printers.ResourcePrinter, error) {//printflag转printer函数
    		o.PrintFlags.NamePrintFlags.Operation = operation
    		return o.PrintFlags.ToPrinter()
    	}
    
    	o.CmdNamespace = cmdNamespace//设置名称空间
    	o.f = f
    
    	return nil
    }

//运行
    func (o *EditOptions) Run() error {
    	edit := NewDefaultEditor(editorEnvs())//创建editor
    	// editFn is invoked for each edit session (once with a list for normal edit, once for each individual resource in a edit-on-create invocation)
    	editFn := func(infos []*resource.Info) error {//edit函数
    		var (
    			results  = editResults{}
    			original = []byte{}
    			edited   = []byte{}
    			file     string
    			err      error
    		)
    
    		containsError := false
    		// loop until we succeed or cancel editing
    		for {
    			// get the object we're going to serialize as input to the editor
    			var originalObj runtime.Object
    			switch len(infos) {//判断info长度
    			case 1://如果是1个，则设置originalObj 
    				originalObj = infos[0].Object
    			default://否则设置list
    				l := &unstructured.UnstructuredList{
    					Object: map[string]interface{}{
    						"kind":       "List",
    						"apiVersion": "v1",
    						"metadata":   map[string]interface{}{},
    					},
    				}
    				for _, info := range infos {
    					l.Items = append(l.Items, *info.Object.(*unstructured.Unstructured))
    				}
    				originalObj = l//设置originalObj 为list
    			}
    
    			// generate the file to edit
    			buf := &bytes.Buffer{}//构造buffer
    			var w io.Writer = buf//定义writer
    			if o.WindowsLineEndings {//如果是windows，包装windows行结尾的writer
    				w = crlf.NewCRLFWriter(w)
    			}
    
    			if o.editPrinterOptions.addHeader {//如果指定了addHeader，则添加头注释
    				results.header.writeTo(w, o.EditMode)
    			}
    
    			if !containsError {//如果没错误
    				if err := o.editPrinterOptions.PrintObj(originalObj, w); err != nil {//打印原始对象到writer
    					return preservedFile(err, results.file, o.ErrOut)//有错误返回
    				}
    				original = buf.Bytes()//保存原始的数据
    			} else {
    				// In case of an error, preserve the edited file.
    				// Remove the comments (header) from it since we already
    				// have included the latest header in the buffer above.
    				buf.Write(cmdutil.ManualStrip(edited))
    			}
    
    			// launch the editor
    			editedDiff := edited
    			edited, file, err = edit.LaunchTempFile(fmt.Sprintf("%s-edit-", filepath.Base(os.Args[0])), o.editPrinterOptions.ext, buf)//启动编辑
    			if err != nil {
    				return preservedFile(err, results.file, o.ErrOut)//保留文件，返回错误
    			}
    			// If we're retrying the loop because of an error, and no change was made in the file, short-circuit
    			if containsError && bytes.Equal(cmdutil.StripComments(editedDiff), cmdutil.StripComments(edited)) {//如果有错误，则返回
    				return preservedFile(fmt.Errorf("%s", "Edit cancelled, no valid changes were saved."), file, o.ErrOut)//保留文件，返回错误
    			}
    			// cleanup any file from the previous pass
    			if len(results.file) > 0 {//删除文件
    				os.Remove(results.file)
    			}
    			klog.V(4).Infof("User edited:\n%s", string(edited))
    
    			// Apply validation
    			schema, err := o.f.Validator(o.EnableValidation)//构造validator
    			if err != nil {
    				return preservedFile(err, file, o.ErrOut)// 保留文件，返回错误
    			}
    			err = schema.ValidateBytes(cmdutil.StripComments(edited))//校验编辑后的文件
    			if err != nil {
    				results = editResults{
    					file: file,
    				}
    				containsError = true
    				fmt.Fprintln(o.ErrOut, results.addError(apierrors.NewInvalid(corev1.SchemeGroupVersion.WithKind("").GroupKind(),
    					"", field.ErrorList{field.Invalid(nil, "The edited file failed validation", fmt.Sprintf("%v", err))}), infos[0]))//打印告警
    				continue//继续
    			}
    
    			// Compare content without comments
    			if bytes.Equal(cmdutil.StripComments(original), cmdutil.StripComments(edited)) {//如果原文件和编辑后的文件去掉注释，内容相同
    				os.Remove(file)//删除文件
    				fmt.Fprintln(o.ErrOut, "Edit cancelled, no changes made.")//打印信息
    				return nil//返回
    			}
    
    			lines, err := hasLines(bytes.NewBuffer(edited))//判断是否有行
    			if err != nil {
    				return preservedFile(err, file, o.ErrOut)// 保留文件，返回错误
    			}
    			if !lines {//没有行
    				os.Remove(file)//删除文件
    				fmt.Fprintln(o.ErrOut, "Edit cancelled, saved file was empty.")//提示信息
    				return nil//返回
    			}
    
    			results = editResults{//构造editResults
    				file: file,
    			}
    
    			// parse the edited file
    			updatedInfos, err := o.updatedResultGetter(edited).Infos()//获取编辑后的info
    			if err != nil {
    				// syntax error
    				containsError = true
    				results.header.reasons = append(results.header.reasons, editReason{head: fmt.Sprintf("The edited file had a syntax error: %v", err)})//语法错误继续
    				continue
    			}
    			// not a syntax error as it turns out...
    			containsError = false
    			updatedVisitor := resource.InfoListVisitor(updatedInfos)//访问编辑后的info
    
    			// need to make sure the original namespace wasn't changed while editing
    			if err := updatedVisitor.Visit(resource.RequireNamespace(o.CmdNamespace)); err != nil {
    				return preservedFile(err, file, o.ErrOut)
    			}
    
    			// iterate through all items to apply annotations
    			if err := o.visitAnnotation(updatedVisitor); err != nil {
    				return preservedFile(err, file, o.ErrOut)
    			}
    
    			switch o.EditMode {判断编辑模式
    			case NormalEditMode:
    				err = o.visitToPatch(infos, updatedVisitor, &results)
    			case ApplyEditMode://apply编辑模式
    				err = o.visitToApplyEditPatch(infos, updatedVisitor)
    			case EditBeforeCreateMode:
    				err = o.visitToCreate(updatedVisitor)
    			default:
    				err = fmt.Errorf("unsupported edit mode %q", o.EditMode)
    			}
    			if err != nil {
    				return preservedFile(err, results.file, o.ErrOut)
    			}
    
    			// Handle all possible errors
    			//
    			// 1. retryable: propose kubectl replace -f
    			// 2. notfound: indicate the location of the saved configuration of the deleted resource
    			// 3. invalid: retry those on the spot by looping ie. reloading the editor
    			if results.retryable > 0 {
    				fmt.Fprintf(o.ErrOut, "You can run `%s replace -f %s` to try this update again.\n", filepath.Base(os.Args[0]), file)
    				return cmdutil.ErrExit
    			}
    			if results.notfound > 0 {
    				fmt.Fprintf(o.ErrOut, "The edits you made on deleted resources have been saved to %q\n", file)
    				return cmdutil.ErrExit
    			}
    
    			if len(results.edit) == 0 {
    				if results.notfound == 0 {
    					os.Remove(file)
    				} else {
    					fmt.Fprintf(o.Out, "The edits you made on deleted resources have been saved to %q\n", file)
    				}
    				return nil
    			}
    
    			if len(results.header.reasons) > 0 {
    				containsError = true
    			}
    		}
    	}
    
    	switch o.EditMode {//判断编辑模式
    	// If doing normal edit we cannot use Visit because we need to edit a list for convenience. Ref: #20519
    	case NormalEditMode:
    		infos, err := o.OriginalResult.Infos()
    		if err != nil {
    			return err
    		}
    		if len(infos) == 0 {
    			return errors.New("edit cancelled, no objects found")
    		}
    		return editFn(infos)
    	case ApplyEditMode://apply编辑模式
    		infos, err := o.OriginalResult.Infos()//获取原始info
    		if err != nil {
    			return err
    		}
    		var annotationInfos []*resource.Info
    		for i := range infos {//遍历info
    			data, err := util.GetOriginalConfiguration(infos[i].Object)//获取原始配置
    			if err != nil {
    				return err
    			}
    			if data == nil {
    				continue
    			}
    
    			tempInfos, err := o.updatedResultGetter(data).Infos()//获取info
    			if err != nil {
    				return err
    			}
    			annotationInfos = append(annotationInfos, tempInfos[0])//注解的info
    		}
    		if len(annotationInfos) == 0 {
    			return errors.New("no last-applied-configuration annotation found on resources, to create the annotation, use command `kubectl apply set-last-applied --create-annotation`")
    		}
    		return editFn(annotationInfos)//执行编辑
    	// If doing an edit before created, we don't want a list and instead want the normal behavior as kubectl create.
    	case EditBeforeCreateMode:
    		return o.OriginalResult.Visit(func(info *resource.Info, err error) error {
    			return editFn([]*resource.Info{info})
    		})
    	default:
    		return fmt.Errorf("unsupported edit mode %q", o.EditMode)
    	}
    }

//应用patch到服务端
    func (o *EditOptions) visitToApplyEditPatch(originalInfos []*resource.Info, patchVisitor resource.Visitor) error {
    	err := patchVisitor.Visit(func(info *resource.Info, incomingErr error) error {//访问result
    		editObjUID, err := meta.NewAccessor().UID(info.Object)//获取uid
    		if err != nil {
    			return err
    		}
    
    		var originalInfo *resource.Info
    		for _, i := range originalInfos {//遍历原始的info
    			originalObjUID, err := meta.NewAccessor().UID(i.Object)//获取原始uid
    			if err != nil {
    				return err
    			}
    			if editObjUID == originalObjUID {//编辑的uid和原始uid相同
    				originalInfo = i
    				break
    			}
    		}
    		if originalInfo == nil {
    			return fmt.Errorf("no original object found for %#v", info.Object)
    		}
    
    		originalJS, err := encodeToJSON(originalInfo.Object.(runtime.Unstructured))//把原始的obj转json
    		if err != nil {
    			return err
    		}
    
    		editedJS, err := encodeToJSON(info.Object.(runtime.Unstructured))//编辑后的info转json
    		if err != nil {
    			return err
    		}
    
    		if reflect.DeepEqual(originalJS, editedJS) {//json相同，跳过
    			printer, err := o.ToPrinter("skipped")
    			if err != nil {
    				return err
    			}
    			return printer.PrintObj(info.Object, o.Out)
    		}
    		err = o.annotationPatch(info)//应用patch到服务端
    		if err != nil {
    			return err
    		}
    
    		printer, err := o.ToPrinter("edited")// print flag转printer
    		if err != nil {
    			return err
    		}
    		return printer.PrintObj(info.Object, o.Out)// 打印对象
    	})
    	return err
    }

func (o *EditOptions) annotationPatch(update *resource.Info) error {
    	patch, _, patchType, err := GetApplyPatch(update.Object.(runtime.Unstructured))//获取patch
    	if err != nil {
    		return err
    	}
    	mapping := update.ResourceMapping()//获取mapping
    	client, err := o.f.UnstructuredClientForMapping(mapping)//获取client
    	if err != nil {
    		return err
    	}
    	helper := resource.NewHelper(client, mapping)//构造helper
    	_, err = helper.Patch(o.CmdNamespace, update.Name, patchType, patch, nil)//应用patch到服务端
    	if err != nil {
    		return err
    	}
    	return nil
    }

//获取patch
    func GetApplyPatch(obj runtime.Unstructured) ([]byte, []byte, types.PatchType, error) {
    	beforeJSON, err := encodeToJSON(obj)//obj转json
    	if err != nil {
    		return nil, []byte(""), types.MergePatchType, err
    	}
    	objCopy := obj.DeepCopyObject()//拷贝obj
    	accessor := meta.NewAccessor()
    	annotations, err := accessor.Annotations(objCopy)//获取annotation
    	if err != nil {
    		return nil, beforeJSON, types.MergePatchType, err
    	}
    	if annotations == nil {
    		annotations = map[string]string{}
    	}
    	annotations[corev1.LastAppliedConfigAnnotation] = string(beforeJSON)//设置lastAppliedConfiguration注解
    	accessor.SetAnnotations(objCopy, annotations)//设置注解
    	afterJSON, err := encodeToJSON(objCopy.(runtime.Unstructured))//对象转json
    	if err != nil {
    		return nil, beforeJSON, types.MergePatchType, err
    	}
    	patch, err := jsonpatch.CreateMergePatch(beforeJSON, afterJSON)//创建patch
    	return patch, beforeJSON, types.MergePatchType, err
    }

[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAaHhwamF2YTE_size_8_color_FFFFFF_t_70_g_se_x_16]: https://img-blog.csdnimg.cn/20211007094240106.jpg?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBAaHhwamF2YTE=,size_8,color_FFFFFF,t_70,g_se,x_16
[istio_50]: https://mp.weixin.qq.com/s/_OPMjmWCDSTlmbAxytg33A
[istio]: https://mp.weixin.qq.com/s/kjvtno_UzJAGr1joxm3tvw
[istio_istio]: https://mp.weixin.qq.com/s/e2-p_NY31Mc5y07S4Bb1JQ
[istio 1]: https://mp.weixin.qq.com/s/iTV0SCQLhSOTYncp3PxoHQ
[istio 2]: https://mp.weixin.qq.com/s/eINlrT242RlAwfuZu1_PcA
[envoyfilter_istio_-http-rbac-_AuthorizationPolicy]: https://mp.weixin.qq.com/s/Q-yTGBNqkjOov49LTXPrPA
[envoyfilter_istio_-02-http-corsFilter-_vs]: https://mp.weixin.qq.com/s/bFMdrT7OKSqoWv8pDXOIqQ
[envoyfilter_istio_-03-http-csrf filter-_csrf]: https://mp.weixin.qq.com/s/dlG9phV-kMMxs4UPzuRNYg
[envoyfilter_istio_http-jwt_authn-_RequestAuthorization]: https://mp.weixin.qq.com/s/IfrJ-FdLYsdhPkDrcO_YXA
[envoyfilter_istio_-05-fault-filter-_vs]: https://mp.weixin.qq.com/s/a4gDXqD8uswgglMwkUph2Q
[envoyfilter_istio_-06-http-match-_vs]: https://mp.weixin.qq.com/s/TpS3DHdcaJiPivIS_jsIGw
[envoyfilter_istio_-07-_dr]: https://mp.weixin.qq.com/s/k-zJm7n7OOKg6MotQJYPAA
[envoyfilter_istio_-08-]: https://mp.weixin.qq.com/s/n_bJ3saNeTtXRprIymhwzg
[envoyfilter_istio_-09-http-route filter]: https://mp.weixin.qq.com/s/JAeZr0BMVQxIrB3S_7Ru0A
[envoyfilter_istio_-network filter-redis proxy]: https://mp.weixin.qq.com/s/B9IPTI8F3q42nVkqbQRlPw
[envoyfilter_istio_-network filter-HttpConnectionManager]: https://mp.weixin.qq.com/s/W3OPQWkCVvuHGS49cTNhlg
[envoyfilter_istio_-ratelimit-istio ratelimit]: https://mp.weixin.qq.com/s/KgiDsELNol27mgZvDbFsqw