kubectl源码分析之apply view-last-applied

红太狼 2023-02-19 14:29 215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]

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type ViewLastAppliedOptions struct {//viewlastapplied结构体
    	FilenameOptions              resource.FilenameOptions
    	Selector                     string
    	LastAppliedConfigurationList []string
    	OutputFormat                 string
    	All                          bool
    	Factory                      cmdutil.Factory
    
    	genericclioptions.IOStreams
    }

func NewViewLastAppliedOptions(ioStreams genericclioptions.IOStreams) *ViewLastAppliedOptions {//初始化结构体
    	return &ViewLastAppliedOptions{
    		OutputFormat: "yaml",
    
    		IOStreams: ioStreams,
    	}
    }

//创建viewLastApplied命令
    func NewCmdApplyViewLastApplied(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *cobra.Command {
    	options := NewViewLastAppliedOptions(ioStreams)//初始化结构体
    
    	cmd := &cobra.Command{//创建cobra命令
    		Use:                   "view-last-applied (TYPE [NAME | -l label] | TYPE/NAME | -f FILENAME)",
    		DisableFlagsInUseLine: true,
    		Short:                 i18n.T("View latest last-applied-configuration annotations of a resource/object"),
    		Long:                  applyViewLastAppliedLong,
    		Example:               applyViewLastAppliedExample,
    		Run: func(cmd *cobra.Command, args []string) {
    			cmdutil.CheckErr(options.Complete(cmd, f, args))//准备
    			cmdutil.CheckErr(options.Validate(cmd))//校验
    			cmdutil.CheckErr(options.RunApplyViewLastApplied(cmd))//运行
    		},
    	}
    
    	cmd.Flags().StringVarP(&options.OutputFormat, "output", "o", options.OutputFormat, "Output format. Must be one of yaml|json")//输出选项
    	cmd.Flags().StringVarP(&options.Selector, "selector", "l", options.Selector, "Selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)")//selector选项
    	cmd.Flags().BoolVar(&options.All, "all", options.All, "Select all resources in the namespace of the specified resource types")//all选项
    	usage := "that contains the last-applied-configuration annotations"
    	cmdutil.AddFilenameOptionFlags(cmd, &options.FilenameOptions, usage)//文件选项
    
    	return cmd
    }

//准备
    func (o *ViewLastAppliedOptions) Complete(cmd *cobra.Command, f cmdutil.Factory, args []string) error {
    	cmdNamespace, enforceNamespace, err := f.ToRawKubeConfigLoader().Namespace()//获取名称空间和enforce名称空间
    	if err != nil {
    		return err
    	}
    
    	r := f.NewBuilder().
    		Unstructured().
    		NamespaceParam(cmdNamespace).DefaultNamespace().
    		FilenameParam(enforceNamespace, &o.FilenameOptions).
    		ResourceTypeOrNameArgs(enforceNamespace, args...).
    		SelectAllParam(o.All).
    		LabelSelectorParam(o.Selector).
    		Latest().
    		Flatten().
    		Do()//用builder构造result对象
    	err = r.Err()
    	if err != nil {
    		return err
    	}
    
    	err = r.Visit(func(info *resource.Info, err error) error {visit result
    		if err != nil {
    			return err
    		}
    
    		configString, err := util.GetOriginalConfiguration(info.Object)//获取last-applied-configuration配置
    		if err != nil {
    			return err
    		}
    		if configString == nil {//配置为空返回错误
    			return cmdutil.AddSourceToErr(fmt.Sprintf("no last-applied-configuration annotation found on resource: %s\n", info.Name), info.Source, err)
    		}
    		o.LastAppliedConfigurationList = append(o.LastAppliedConfigurationList, string(configString))//追加配置
    		return nil
    	})
    
    	if err != nil {
    		return err
    	}
    
    	return nil
    }
    
    // Validate checks ViewLastAppliedOptions for validity.
    func (o *ViewLastAppliedOptions) Validate(cmd *cobra.Command) error {
    	return nil
    }

//运行
    func (o *ViewLastAppliedOptions) RunApplyViewLastApplied(cmd *cobra.Command) error {
    	for _, str := range o.LastAppliedConfigurationList {//遍历配置
    		switch o.OutputFormat {
    		case "json"://json格式输出
    			jsonBuffer := &bytes.Buffer{}
    			err := json.Indent(jsonBuffer, []byte(str), "", "  ")
    			if err != nil {
    				return err
    			}
    			fmt.Fprint(o.Out, string(jsonBuffer.Bytes()))
    		case "yaml"://yaml格式输出
    			yamlOutput, err := yaml.JSONToYAML([]byte(str))
    			if err != nil {
    				return err
    			}
    			fmt.Fprint(o.Out, string(yamlOutput))
    		default:
    			return cmdutil.UsageErrorf(
    				cmd,
    				"Unexpected -o output mode: %s, the flag 'output' must be one of yaml|json",
    				o.OutputFormat)
    		}
    	}
    
    	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