kubectl源码分析之rollout pause_kubectl rollout pause-优快云博客

type PauseOptions struct {//pause结构体
	PrintFlags *genericclioptions.PrintFlags
	ToPrinter  func(string) (printers.ResourcePrinter, error)

	Pauser           polymorphichelpers.ObjectPauserFunc
	Builder          func() *resource.Builder
	Namespace        string
	EnforceNamespace bool
	Resources        []string

	resource.FilenameOptions
	genericclioptions.IOStreams
}

//创建pause命令
func NewCmdRolloutPause(f cmdutil.Factory, streams genericclioptions.IOStreams) *cobra.Command {
	o := &PauseOptions{//初始化结构体
		PrintFlags: genericclioptions.NewPrintFlags("paused").WithTypeSetter(scheme.Scheme),
		IOStreams:  streams,
	}

	validArgs := []string{"deployment"}

	cmd := &cobra.Command{//创建cobra命令
		Use:                   "pause RESOURCE",
		DisableFlagsInUseLine: true,
		Short:                 i18n.T("Mark the provided resource as paused"),
		Long:                  pauseLong,
		Example:               pauseExample,
		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.RunPause())//运行
		},
		ValidArgs: validArgs,//有效参数
	}

	o.PrintFlags.AddFlags(cmd)//设置打印选项

	usage := "identifying the resource to get from a server."
	cmdutil.AddFilenameOptionFlags(cmd, &o.FilenameOptions, usage)//设置文件选项
	return cmd
}

//准备方法
func (o *PauseOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
	o.Pauser = polymorphichelpers.ObjectPauserFn//设置Pauser函数

	var err error
	o.Namespace, o.EnforceNamespace, err = f.ToRawKubeConfigLoader().Namespace()//获取namespace和enforcenameapace
	if err != nil {
		return err
	}

	o.Resources = args//设置resources
	o.Builder = f.NewBuilder//设置Builder

	o.ToPrinter = func(operation string) (printers.ResourcePrinter, error) {//printflag转printer函数
		o.PrintFlags.NamePrintFlags.Operation = operation
		return o.PrintFlags.ToPrinter()
	}

	return nil
}

//校验函数
func (o *PauseOptions) Validate() error {
	if len(o.Resources) == 0 && cmdutil.IsFilenameSliceEmpty(o.Filenames, o.Kustomize) {//资源和文件至少指定一个
		return fmt.Errorf("required resource not specified")
	}
	return nil
}

//运行
func (o *PauseOptions) RunPause() error {
	r := o.Builder().
		WithScheme(scheme.Scheme, scheme.Scheme.PrioritizedVersionsAllGroups()...).
		NamespaceParam(o.Namespace).DefaultNamespace().
		FilenameParam(o.EnforceNamespace, &o.FilenameOptions).
		ResourceTypeOrNameArgs(true, o.Resources...).
		ContinueOnError().
		Latest().
		Flatten().
		Do()//构造info对象
	if err := r.Err(); err != nil {
		return err
	}

	allErrs := []error{}
	infos, err := r.Infos()//获取info对象
	if err != nil {
		// restore previous command behavior where
		// an error caused by retrieving infos due to
		// at least a single broken object did not result
		// in an immediate return, but rather an overall
		// aggregation of errors.
		allErrs = append(allErrs, err)
	}

	for _, patch := range set.CalculatePatches(infos, scheme.DefaultJSONEncoder(), set.PatchFn(o.Pauser)) {//计算patches，然后遍历
		info := patch.Info

		if patch.Err != nil {//patch有error，处理error
			resourceString := info.Mapping.Resource.Resource
			if len(info.Mapping.Resource.Group) > 0 {
				resourceString = resourceString + "." + info.Mapping.Resource.Group
			}
			allErrs = append(allErrs, fmt.Errorf("error: %s %q %v", resourceString, info.Name, patch.Err))
			continue
		}

		if string(patch.Patch) == "{}" || len(patch.Patch) == 0 {//patch为空
			printer, err := o.ToPrinter("already paused")//printflag转printer
			if err != nil {
				allErrs = append(allErrs, err)
				continue
			}
			if err = printer.PrintObj(info.Object, o.Out); err != nil {//打印对象
				allErrs = append(allErrs, err)
			}
			continue
		}

		obj, err := resource.NewHelper(info.Client, info.Mapping).Patch(info.Namespace, info.Name, types.StrategicMergePatchType, patch.Patch, nil)//应用patch到服务端
		if err != nil {
			allErrs = append(allErrs, fmt.Errorf("failed to patch: %v", err))
			continue
		}

		info.Refresh(obj, true)//刷新obj
		printer, err := o.ToPrinter("paused")// print flag转printer
		if err != nil {
			allErrs = append(allErrs, err)
			continue
		}
		if err = printer.PrintObj(info.Object, o.Out); err != nil {//打印结果
			allErrs = append(allErrs, err)
		}
	}

	return utilerrors.NewAggregate(allErrs)
}