kubectl源码分析之set resource

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原创最新推荐文章于 2026-07-28 20:15:43 发布 666 阅读 AI 写同款· GEO 优化 ›

kubectl滚动更新资源 rollout Manage the rollout of a resource. Valid resource types include: * deployments * daemonsets * statefulsets Examples: # Rollback to the previous deployment kubectl rollout undo deployment/abc # Check the rollout status of a da 阅读详情

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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 SetResourcesOptions struct {//setresource结构体
	resource.FilenameOptions

	PrintFlags  *genericclioptions.PrintFlags
	RecordFlags *genericclioptions.RecordFlags

	Infos             []*resource.Info
	Selector          string
	ContainerSelector string
	Output            string
	All               bool
	Local             bool

	DryRun bool

	PrintObj printers.ResourcePrinterFunc
	Recorder genericclioptions.Recorder

	Limits               string
	Requests             string
	ResourceRequirements v1.ResourceRequirements

	UpdatePodSpecForObject polymorphichelpers.UpdatePodSpecForObjectFunc
	Resources              []string

	genericclioptions.IOStreams
}

func NewResourcesOptions(streams genericclioptions.IOStreams) *SetResourcesOptions {
	return &SetResourcesOptions{初始化结构体
		PrintFlags:  genericclioptions.NewPrintFlags("resource requirements updated").WithTypeSetter(scheme.Scheme),
		RecordFlags: genericclioptions.NewRecordFlags(),

		Recorder: genericclioptions.NoopRecorder{},

		ContainerSelector: "*",

		IOStreams: streams,
	}
}

//创建set resource命令
func NewCmdResources(f cmdutil.Factory, streams genericclioptions.IOStreams) *cobra.Command {
	o := NewResourcesOptions(streams)//初始化结构体

	cmd := &cobra.Command{//创建cobra命令
		Use:                   "resources (-f FILENAME | TYPE NAME)  ([--limits=LIMITS & --requests=REQUESTS]",
		DisableFlagsInUseLine: true,
		Short:                 i18n.T("Update resource requests/limits on objects with pod templates"),
		Long:                  fmt.Sprintf(resourcesLong, cmdutil.SuggestAPIResources("kubectl")),
		Example:               resourcesExample,
		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.Run())//运行
		},
	}

	o.PrintFlags.AddFlags(cmd)//设置打印选项
	o.RecordFlags.AddFlags(cmd)//设置record选项

	//usage := "Filename, directory, or URL to a file identifying the resource to get from the server"
	//kubectl.AddJsonFilenameFlag(cmd, &options.Filenames, usage)
	usage := "identifying the resource to get from a server."
	cmdutil.AddFilenameOptionFlags(cmd, &o.FilenameOptions, usage)//设置文件选项
	cmd.Flags().BoolVar(&o.All, "all", o.All, "Select all resources, including uninitialized ones, in the namespace of the specified resource types")//设置all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)")//设置selector选项
	cmd.Flags().StringVarP(&o.ContainerSelector, "containers", "c", o.ContainerSelector, "The names of containers in the selected pod templates to change, all containers are selected by default - may use wildcards")//设置container选项
	cmd.Flags().BoolVar(&o.Local, "local", o.Local, "If true, set resources will NOT contact api-server but run locally.")//设置local选项
	cmdutil.AddDryRunFlag(cmd)//设置干跑选项
	cmdutil.AddIncludeUninitializedFlag(cmd)
	cmd.Flags().StringVar(&o.Limits, "limits", o.Limits, "The resource requirement requests for this container.  For example, 'cpu=100m,memory=256Mi'.  Note that server side components may assign requests depending on the server configuration, such as limit ranges.")//设置limits选项
	cmd.Flags().StringVar(&o.Requests, "requests", o.Requests, "The resource requirement requests for this container.  For example, 'cpu=100m,memory=256Mi'.  Note that server side components may assign requests depending on the server configuration, such as limit ranges.")//设置requests选项
	return cmd
}

//准备函数
func (o *SetResourcesOptions) 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.UpdatePodSpecForObject = polymorphichelpers.UpdatePodSpecForObjectFn//设置updatePodSpecForObject函数
	o.Output = cmdutil.GetFlagString(cmd, "output")//设置output
	o.DryRun = cmdutil.GetDryRunFlag(cmd)//设置干跑

	if o.DryRun {
		o.PrintFlags.Complete("%s (dry run)")
	}
	printer, err := o.PrintFlags.ToPrinter()//print flag转printer
	if err != nil {
		return err
	}
	o.PrintObj = printer.PrintObj//设置printObj函数

	cmdNamespace, enforceNamespace, err := f.ToRawKubeConfigLoader().Namespace()//获取namespace和enforceNamespace
	if err != nil {
		return err
	}

	builder := f.NewBuilder().
		WithScheme(scheme.Scheme, scheme.Scheme.PrioritizedVersionsAllGroups()...).
		LocalParam(o.Local).
		ContinueOnError().
		NamespaceParam(cmdNamespace).DefaultNamespace().
		FilenameParam(enforceNamespace, &o.FilenameOptions).
		Flatten()//构造info对象

	if !o.Local {
		builder.LabelSelectorParam(o.Selector).
			ResourceTypeOrNameArgs(o.All, args...).
			Latest()
	} else {
		// if a --local flag was provided, and a resource was specified in the form
		// <resource>/<name>, fail immediately as --local cannot query the api server
		// for the specified resource.
		// TODO: this should be in the builder - if someone specifies tuples, fail when
		// local is true
		if len(args) > 0 {
			return resource.LocalResourceError
		}
	}

	o.Infos, err = builder.Do().Infos()//设置info对象
	if err != nil {
		return err
	}
	return nil
}

//校验
func (o *SetResourcesOptions) Validate() error {
	var err error
	if o.All && len(o.Selector) > 0 {//all和selector不能同时设置
		return fmt.Errorf("cannot set --all and --selector at the same time")
	}
	if len(o.Limits) == 0 && len(o.Requests) == 0 {//至少有一个limits或requests
		return fmt.Errorf("you must specify an update to requests or limits (in the form of --requests/--limits)")
	}

	o.ResourceRequirements, err = generateversioned.HandleResourceRequirementsV1(map[string]string{"limits": o.Limits, "requests": o.Requests})//解析limits和requests参数
	if err != nil {
		return err
	}

	return nil
}

//运行
func (o *SetResourcesOptions) Run() error {
	allErrs := []error{}
	patches := CalculatePatches(o.Infos, scheme.DefaultJSONEncoder(), func(obj runtime.Object) ([]byte, error) {//计算patch
		transformed := false
		_, err := o.UpdatePodSpecForObject(obj, func(spec *v1.PodSpec) error {//更新pod
			containers, _ := selectContainers(spec.Containers, o.ContainerSelector)//获取container
			if len(containers) != 0 {
				for i := range containers {//遍历containers
					if len(o.Limits) != 0 && len(containers[i].Resources.Limits) == 0 {
						containers[i].Resources.Limits = make(v1.ResourceList)//构造limits
					}
					for key, value := range o.ResourceRequirements.Limits {
						containers[i].Resources.Limits[key] = value//设置limits
					}

					if len(o.Requests) != 0 && len(containers[i].Resources.Requests) == 0 {
						containers[i].Resources.Requests = make(v1.ResourceList)//构造requests
					}
					for key, value := range o.ResourceRequirements.Requests {
						containers[i].Resources.Requests[key] = value//设置requests
					}
					transformed = true
				}
			} else {
				allErrs = append(allErrs, fmt.Errorf("error: unable to find container named %s", o.ContainerSelector))
			}
			return nil
		})
		if err != nil {
			return nil, err
		}
		if !transformed {
			return nil, nil
		}
		// record this change (for rollout history)
		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)
		}

		return runtime.Encode(scheme.DefaultJSONEncoder(), obj)//obj转json
	})

	for _, patch := range patches {//遍历patches
		info := patch.Info
		name := info.ObjectName()
		if patch.Err != nil {
			allErrs = append(allErrs, fmt.Errorf("error: %s %v\n", name, patch.Err))
			continue
		}

		//no changes
		if string(patch.Patch) == "{}" || len(patch.Patch) == 0 {
			allErrs = append(allErrs, fmt.Errorf("info: %s was not changed\n", name))
			continue
		}

		if o.Local || o.DryRun {//如果是lcoal或干跑，则打印对象
			if err := o.PrintObj(info.Object, o.Out); err != nil {
				allErrs = append(allErrs, err)
			}
			continue
		}

		actual, err := resource.NewHelper(info.Client, info.Mapping).Patch(info.Namespace, info.Name, types.StrategicMergePatchType, patch.Patch, nil)// 应用patch
		if err != nil {
			allErrs = append(allErrs, fmt.Errorf("failed to patch limit update to pod template %v", err))
			continue
		}

		if err := o.PrintObj(actual, o.Out); err != nil {//打印对象
			allErrs = append(allErrs, err)
		}
	}
	return utilerrors.NewAggregate(allErrs)
}