kubectl源码分析之cordon and uncordon

超、凢脫俗 2023-02-16 12:27 98阅读 0赞

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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_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]

加qq群，请联系：

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加微信群请联系：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h4cGphdmEx_size_16_color_FFFFFF_t_70 1][]

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type DrainCmdOptions struct {//drain结构体
    	PrintFlags *genericclioptions.PrintFlags
    	ToPrinter  func(string) (printers.ResourcePrinterFunc, error)
    
    	Namespace string
    
    	drainer   *drain.Helper
    	nodeInfos []*resource.Info
    
    	genericclioptions.IOStreams
    }

//创建cordon命令
    func NewCmdCordon(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *cobra.Command {
    	o := NewDrainCmdOptions(f, ioStreams)//初始化结构体
    
    	cmd := &cobra.Command{//创建cobra命令
    		Use:                   "cordon NODE",
    		DisableFlagsInUseLine: true,
    		Short:                 i18n.T("Mark node as unschedulable"),
    		Long:                  cordonLong,
    		Example:               cordonExample,
    		Run: func(cmd *cobra.Command, args []string) {
    			cmdutil.CheckErr(o.Complete(f, cmd, args))//准备
    			cmdutil.CheckErr(o.RunCordonOrUncordon(true))//运行
    		},
    	}
    	cmd.Flags().StringVarP(&o.drainer.Selector, "selector", "l", o.drainer.Selector, "Selector (label query) to filter on")//selector选项
    	cmdutil.AddDryRunFlag(cmd)//干跑选项
    	return cmd
    }

//创建uncordon命令
    func NewCmdUncordon(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *cobra.Command {
    	o := NewDrainCmdOptions(f, ioStreams)//初始化结构体
    
    	cmd := &cobra.Command{//创建cobra命令
    		Use:                   "uncordon NODE",
    		DisableFlagsInUseLine: true,
    		Short:                 i18n.T("Mark node as schedulable"),
    		Long:                  uncordonLong,
    		Example:               uncordonExample,
    		Run: func(cmd *cobra.Command, args []string) {
    			cmdutil.CheckErr(o.Complete(f, cmd, args))//准备
    			cmdutil.CheckErr(o.RunCordonOrUncordon(false))//运行
    		},
    	}
    	cmd.Flags().StringVarP(&o.drainer.Selector, "selector", "l", o.drainer.Selector, "Selector (label query) to filter on")//selector选项
    	cmdutil.AddDryRunFlag(cmd)//干跑选项
    	return cmd
    }

//准备函数
    func (o *DrainCmdOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
    	var err error
    
    	if len(args) == 0 && !cmd.Flags().Changed("selector") {//如果参数和selector都没指定则报错
    		return cmdutil.UsageErrorf(cmd, fmt.Sprintf("USAGE: %s [flags]", cmd.Use))
    	}
    	if len(args) > 0 && len(o.drainer.Selector) > 0 {//如果参数和selector同时指定则报错
    		return cmdutil.UsageErrorf(cmd, "error: cannot specify both a node name and a --selector option")
    	}
    
    	o.drainer.DryRun = cmdutil.GetDryRunFlag(cmd)//设置干跑
    
    	if o.drainer.Client, err = f.KubernetesClientSet(); err != nil {//设置clientset
    		return err
    	}
    
    	if len(o.drainer.PodSelector) > 0 {//解析podSelector
    		if _, err := labels.Parse(o.drainer.PodSelector); err != nil {
    			return errors.New("--pod-selector=<pod_selector> must be a valid label selector")
    		}
    	}
    
    	o.nodeInfos = []*resource.Info{}//创建info对象
    
    	o.Namespace, _, err = f.ToRawKubeConfigLoader().Namespace()//设置Namespace
    	if err != nil {
    		return err
    	}
    
    	o.ToPrinter = func(operation string) (printers.ResourcePrinterFunc, error) {//设置printflag转printer函数
    		o.PrintFlags.NamePrintFlags.Operation = operation
    		if o.drainer.DryRun {
    			o.PrintFlags.Complete("%s (dry run)")
    		}
    
    		printer, err := o.PrintFlags.ToPrinter()
    		if err != nil {
    			return nil, err
    		}
    
    		return printer.PrintObj, nil
    	}
    
    	builder := f.NewBuilder().
    		WithScheme(scheme.Scheme, scheme.Scheme.PrioritizedVersionsAllGroups()...).
    		NamespaceParam(o.Namespace).DefaultNamespace().
    		ResourceNames("nodes", args...).
    		SingleResourceType().
    		Flatten()//构造result对象
    
    	if len(o.drainer.Selector) > 0 {
    		builder = builder.LabelSelectorParam(o.drainer.Selector).
    			ResourceTypes("nodes")
    	}
    
    	r := builder.Do()//构造result对象
    
    	if err = r.Err(); err != nil {
    		return err
    	}
    
    	return r.Visit(func(info *resource.Info, err error) error {//visit result对象
    		if err != nil {
    			return err
    		}
    		if info.Mapping.Resource.GroupResource() != (schema.GroupResource{Group: "", Resource: "nodes"}) {//判断是否node
    			return fmt.Errorf("error: expected resource of type node, got %q", info.Mapping.Resource)
    		}
    
    		o.nodeInfos = append(o.nodeInfos, info)//append node info
    		return nil
    	})
    }

//执行cordon或uncordon
    func (o *DrainCmdOptions) RunCordonOrUncordon(desired bool) error {
    	cordonOrUncordon := "cordon"//默认是cordon
    	if !desired {// 如果desired为false，则为uncordon
    		cordonOrUncordon = "un" + cordonOrUncordon
    	}
    
    	for _, nodeInfo := range o.nodeInfos {//遍历info
    
    		printError := func(err error) {//打印错误函数
    			fmt.Fprintf(o.ErrOut, "error: unable to %s node %q: %v\n", cordonOrUncordon, nodeInfo.Name, err)
    		}
    
    		gvk := nodeInfo.ResourceMapping().GroupVersionKind//获取info的gvk
    		if gvk.Kind == "Node" {//如果kind为node
    			c, err := drain.NewCordonHelperFromRuntimeObject(nodeInfo.Object, scheme.Scheme, gvk)//构造cordon帮助工具
    			if err != nil {
    				printError(err)
    				continue
    			}
    
    			if updateRequired := c.UpdateIfRequired(desired); !updateRequired {//判断是否需要更新资源
    				printObj, err := o.ToPrinter(already(desired))//printflag转printer
    				if err != nil {
    					fmt.Fprintf(o.ErrOut, "error: %v\n", err)
    					continue
    				}
    				printObj(nodeInfo.Object, o.Out)//打印结果
    			} else {//如果需要更新资源
    				if !o.drainer.DryRun {//如果非干盘
    					err, patchErr := c.PatchOrReplace(o.drainer.Client)//应用补丁到服务器
    					if patchErr != nil {
    						printError(patchErr)
    					}
    					if err != nil {
    						printError(err)
    						continue
    					}
    				}
    				printObj, err := o.ToPrinter(changed(desired))//printflag转printer
    				if err != nil {
    					fmt.Fprintf(o.ErrOut, "%v\n", err)
    					continue
    				}
    				printObj(nodeInfo.Object, o.Out)//打印结果
    			}
    		} else {
    			printObj, err := o.ToPrinter("skipped")//printflag转printer
    			if err != nil {
    				fmt.Fprintf(o.ErrOut, "%v\n", err)
    				continue
    			}
    			printObj(nodeInfo.Object, o.Out)//打印跳过结果
    		}
    	}
    
    	return nil
    }

[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
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h4cGphdmEx_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200524125723190.jpg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h4cGphdmEx,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h4cGphdmEx_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200610095954628.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h4cGphdmEx,size_16,color_FFFFFF,t_70