kubectl源码分析之set env

青旅半醒 2023-02-13 03:45 138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 EnvOptions struct {//set env结构体
    	PrintFlags *genericclioptions.PrintFlags
    	resource.FilenameOptions
    
    	EnvParams         []string
    	All               bool
    	Resolve           bool
    	List              bool
    	Local             bool
    	Overwrite         bool
    	ContainerSelector string
    	Selector          string
    	From              string
    	Prefix            string
    	Keys              []string
    
    	PrintObj printers.ResourcePrinterFunc
    
    	envArgs                []string
    	resources              []string
    	output                 string
    	dryRun                 bool
    	builder                func() *resource.Builder
    	updatePodSpecForObject polymorphichelpers.UpdatePodSpecForObjectFunc
    	namespace              string
    	enforceNamespace       bool
    	clientset              *kubernetes.Clientset
    
    	genericclioptions.IOStreams
    }

func NewEnvOptions(streams genericclioptions.IOStreams) *EnvOptions {
    	return &EnvOptions{//初始化结构体
    		PrintFlags: genericclioptions.NewPrintFlags("env updated").WithTypeSetter(scheme.Scheme),
    
    		ContainerSelector: "*",
    		Overwrite:         true,
    
    		IOStreams: streams,
    	}
    }

//创建set env命令
    func NewCmdEnv(f cmdutil.Factory, streams genericclioptions.IOStreams) *cobra.Command {
    	o := NewEnvOptions(streams)//初始化结构体
    	cmd := &cobra.Command{//创建cobra命令
    		Use:                   "env RESOURCE/NAME KEY_1=VAL_1 ... KEY_N=VAL_N",
    		DisableFlagsInUseLine: true,
    		Short:                 "Update environment variables on a pod template",
    		Long:                  envLong,
    		Example:               fmt.Sprintf(envExample),
    		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.RunEnv())//运行
    		},
    	}
    	usage := "the resource to update the env"
    	cmdutil.AddFilenameOptionFlags(cmd, &o.FilenameOptions, usage)//设置文件选项
    	cmd.Flags().StringVarP(&o.ContainerSelector, "containers", "c", o.ContainerSelector, "The names of containers in the selected pod templates to change - may use wildcards")//设置container选项
    	cmd.Flags().StringVarP(&o.From, "from", "", "", "The name of a resource from which to inject environment variables")//设置from选项
    	cmd.Flags().StringVarP(&o.Prefix, "prefix", "", "", "Prefix to append to variable names")//设置prefix选项
    	cmd.Flags().StringArrayVarP(&o.EnvParams, "env", "e", o.EnvParams, "Specify a key-value pair for an environment variable to set into each container.")//设置env选项
    	cmd.Flags().StringSliceVarP(&o.Keys, "keys", "", o.Keys, "Comma-separated list of keys to import from specified resource")//设置keys选项
    	cmd.Flags().BoolVar(&o.List, "list", o.List, "If true, display the environment and any changes in the standard format. this flag will removed when we have kubectl view env.")//设置list选项
    	cmd.Flags().BoolVar(&o.Resolve, "resolve", o.Resolve, "If true, show secret or configmap references when listing variables")//设置resolve选项
    	cmd.Flags().StringVarP(&o.Selector, "selector", "l", o.Selector, "Selector (label query) to filter on")//设置selector选项
    	cmd.Flags().BoolVar(&o.Local, "local", o.Local, "If true, set env will NOT contact api-server but run locally.")//设置local选项
    	cmd.Flags().BoolVar(&o.All, "all", o.All, "If true, select all resources in the namespace of the specified resource types")//设置all选项
    	cmd.Flags().BoolVar(&o.Overwrite, "overwrite", o.Overwrite, "If true, allow environment to be overwritten, otherwise reject updates that overwrite existing environment.")//设置overrite选项
    
    	o.PrintFlags.AddFlags(cmd)//设置打印选项
    
    	cmdutil.AddDryRunFlag(cmd)//设置干跑选项
    	return cmd
    }

//准备
    func (o *EnvOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
    	if o.All && len(o.Selector) > 0 {//all和selector不能同时存在
    		return fmt.Errorf("cannot set --all and --selector at the same time")
    	}
    	ok := false
    	o.resources, o.envArgs, ok = envutil.SplitEnvironmentFromResources(args)//获取resource和env
    	if !ok {
    		return fmt.Errorf("all resources must be specified before environment changes: %s", strings.Join(args, " "))
    	}
    
    	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 {
    		// TODO(juanvallejo): This can be cleaned up even further by creating
    		// a PrintFlags struct that binds the --dry-run flag, and whose
    		// ToPrinter method returns a printer that understands how to print
    		// this success message.
    		o.PrintFlags.Complete("%s (dry run)")
    	}
    	printer, err := o.PrintFlags.ToPrinter()//printflag转printer
    	if err != nil {
    		return err
    	}
    	o.PrintObj = printer.PrintObj//设置printObj函数
    
    	o.clientset, err = f.KubernetesClientSet()//设置clientSet
    	if err != nil {
    		return err
    	}
    	o.namespace, o.enforceNamespace, err = f.ToRawKubeConfigLoader().Namespace()//设置namespace和enforceNamespace
    	if err != nil {
    		return err
    	}
    	o.builder = f.NewBuilder//设置builder
    
    	return nil
    }

func (o *EnvOptions) Validate() error {
    	if len(o.Filenames) == 0 && len(o.resources) < 1 {//文件和资源至少有一个
    		return fmt.Errorf("one or more resources must be specified as <resource> <name> or <resource>/<name>")
    	}
    	if o.List && len(o.output) > 0 {//list和output不能同时指定
    		return fmt.Errorf("--list and --output may not be specified together")
    	}
    	if len(o.Keys) > 0 && len(o.From) == 0 {指定keys的时候必须指定from
    		return fmt.Errorf("when specifying --keys, a configmap or secret must be provided with --from")
    	}
    	return nil
    }

//运行
    func (o *EnvOptions) RunEnv() error {
    	env, remove, err := envutil.ParseEnv(append(o.EnvParams, o.envArgs...), o.In)//解析env
    	if err != nil {
    		return err
    	}
    
    	if len(o.From) != 0 {
    		b := o.builder().
    			WithScheme(scheme.Scheme, scheme.Scheme.PrioritizedVersionsAllGroups()...).
    			LocalParam(o.Local).
    			ContinueOnError().
    			NamespaceParam(o.namespace).DefaultNamespace().
    			FilenameParam(o.enforceNamespace, &o.FilenameOptions).
    			Flatten()//构造from的info对象
    
    		if !o.Local {
    			b = b.
    				LabelSelectorParam(o.Selector).
    				ResourceTypeOrNameArgs(o.All, o.From).
    				Latest()
    		}
    
    		infos, err := b.Do().Infos()//获取from info对象
    		if err != nil {
    			return err
    		}
    
    		for _, info := range infos {//遍历from info对象
    			switch from := info.Object.(type) {
    			case *v1.Secret://如果类型是secret
    				for key := range from.Data {//遍历key
    					if contains(key, o.Keys) {//如果keys包含key
    						envVar := v1.EnvVar{
    							Name: keyToEnvName(key),
    							ValueFrom: &v1.EnvVarSource{
    								SecretKeyRef: &v1.SecretKeySelector{
    									LocalObjectReference: v1.LocalObjectReference{
    										Name: from.Name,
    									},
    									Key: key,
    								},
    							},
    						}//构造env
    						env = append(env, envVar)//append env
    					}
    				}
    			case *v1.ConfigMap://如果类型是configMap
    				for key := range from.Data {//遍历key
    					if contains(key, o.Keys) {//如果keys包含key
    						envVar := v1.EnvVar{
    							Name: keyToEnvName(key),
    							ValueFrom: &v1.EnvVarSource{
    								ConfigMapKeyRef: &v1.ConfigMapKeySelector{
    									LocalObjectReference: v1.LocalObjectReference{
    										Name: from.Name,
    									},
    									Key: key,
    								},
    							},
    						}//构造env
    						env = append(env, envVar)//append env
    					}
    				}
    			default:
    				return fmt.Errorf("unsupported resource specified in --from")
    			}
    		}
    	}
    
    	if len(o.Prefix) != 0 {//如果prefix不为空
    		for i := range env {
    			env[i].Name = fmt.Sprintf("%s%s", o.Prefix, env[i].Name)//env名称加prefix
    		}
    	}
    
    	b := o.builder().
    		WithScheme(scheme.Scheme, scheme.Scheme.PrioritizedVersionsAllGroups()...).
    		LocalParam(o.Local).
    		ContinueOnError().
    		NamespaceParam(o.namespace).DefaultNamespace().
    		FilenameParam(o.enforceNamespace, &o.FilenameOptions).
    		Flatten()//构造resource 的info对象
    
    	if !o.Local {
    		b.LabelSelectorParam(o.Selector).
    			ResourceTypeOrNameArgs(o.All, o.resources...).
    			Latest()
    	}
    
    	infos, err := b.Do().Infos()//获取info对象
    	if err != nil {
    		return err
    	}
    	patches := CalculatePatches(infos, scheme.DefaultJSONEncoder(), func(obj runtime.Object) ([]byte, error) {//计算patch
    		_, err := o.updatePodSpecForObject(obj, func(spec *v1.PodSpec) error {//更新pod spec
    			resolutionErrorsEncountered := false
    			containers, _ := selectContainers(spec.Containers, o.ContainerSelector)//选择容器
    			objName, err := meta.NewAccessor().Name(obj)//获取对象名称
    			if err != nil {
    				return err
    			}
    
    			gvks, _, err := scheme.Scheme.ObjectKinds(obj)//从obj获取groupversionkind
    			if err != nil {
    				return err
    			}
    			objKind := obj.GetObjectKind().GroupVersionKind().Kind//获取kind
    			if len(objKind) == 0 {//如果kind为空，则从gvks获取
    				for _, gvk := range gvks {
    					if len(gvk.Kind) == 0 {
    						continue
    					}
    					if len(gvk.Version) == 0 || gvk.Version == runtime.APIVersionInternal {
    						continue
    					}
    
    					objKind = gvk.Kind
    					break
    				}
    			}
    
    			if len(containers) == 0 {//如果容器为空
    				if gvks, _, err := scheme.Scheme.ObjectKinds(obj); err == nil {//获取gvks
    					objKind := obj.GetObjectKind().GroupVersionKind().Kind//获取kind
    					if len(objKind) == 0 {//如果kind为空则从gvks获取
    						for _, gvk := range gvks {
    							if len(gvk.Kind) == 0 {
    								continue
    							}
    							if len(gvk.Version) == 0 || gvk.Version == runtime.APIVersionInternal {
    								continue
    							}
    
    							objKind = gvk.Kind
    							break
    						}
    					}
    
    					fmt.Fprintf(o.ErrOut, "warning: %s/%s does not have any containers matching %q\n", objKind, objName, o.ContainerSelector)//打印错误返回
    				}
    				return nil
    			}
    			for _, c := range containers {//遍历容器
    				if !o.Overwrite {//如果overrite为false，校验env是否有覆盖
    					if err := validateNoOverwrites(c.Env, env); err != nil {
    						return err
    					}
    				}
    
    				c.Env = updateEnv(c.Env, env, remove)//更新env
    				if o.List {//如果list为true
    					resolveErrors := map[string][]string{}
    					store := envutil.NewResourceStore()
    
    					fmt.Fprintf(o.Out, "# %s %s, container %s\n", objKind, objName, c.Name)
    					for _, env := range c.Env {//遍历env
    						// Print the simple value
    						if env.ValueFrom == nil {//打印env
    							fmt.Fprintf(o.Out, "%s=%s\n", env.Name, env.Value)
    							continue
    						}
    
    						// Print the reference version
    						if !o.Resolve {//如果resolve为false,不解析env，打印
    							fmt.Fprintf(o.Out, "# %s from %s\n", env.Name, envutil.GetEnvVarRefString(env.ValueFrom))
    							continue
    						}
    
    						value, err := envutil.GetEnvVarRefValue(o.clientset, o.namespace, store, env.ValueFrom, obj, c)//解析env
    						// Print the resolved value
    						if err == nil {//打印解析后的env
    							fmt.Fprintf(o.Out, "%s=%s\n", env.Name, value)
    							continue
    						}
    
    						// Print the reference version and save the resolve error
    						fmt.Fprintf(o.Out, "# %s from %s\n", env.Name, envutil.GetEnvVarRefString(env.ValueFrom))//解析错误，打印未解析env
    						errString := err.Error()
    						resolveErrors[errString] = append(resolveErrors[errString], env.Name)
    						resolutionErrorsEncountered = true
    					}
    
    					// Print any resolution errors
    					errs := []string{}
    					for err, vars := range resolveErrors {
    						sort.Strings(vars)
    						errs = append(errs, fmt.Sprintf("error retrieving reference for %s: %v", strings.Join(vars, ", "), err))//组装error
    					}
    					sort.Strings(errs)//排序error
    					for _, err := range errs {//打印错误
    						fmt.Fprintln(o.ErrOut, err)
    					}
    				}
    			}
    			if resolutionErrorsEncountered {//解析错误返回
    				return errors.New("failed to retrieve valueFrom references")
    			}
    			return nil
    		})
    
    		if err == nil {
    			return runtime.Encode(scheme.DefaultJSONEncoder(), obj)//obj转json
    		}
    		return nil, err
    	})
    
    	if o.List {
    		return nil
    	}
    
    	allErrs := []error{}
    
    	for _, patch := range patches {//遍历patch
    		info := patch.Info
    		if patch.Err != nil {
    			name := info.ObjectName()
    			allErrs = append(allErrs, fmt.Errorf("error: %s %v\n", name, patch.Err))
    			continue
    		}
    
    		// no changes
    		if string(patch.Patch) == "{}" || len(patch.Patch) == 0 {
    			continue
    		}
    
    		if o.Local || o.dryRun {//loal或干跑，打印结果继续
    			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到服务端
    		if err != nil {
    			allErrs = append(allErrs, fmt.Errorf("failed to patch env update to pod template: %v", err))
    			continue
    		}
    
    		// make sure arguments to set or replace environment variables are set
    		// before returning a successful message
    		if len(env) == 0 && len(o.envArgs) == 0 {//如果env和envArgs为空则报错
    			return fmt.Errorf("at least one environment variable must be provided")
    		}
    
    		if err := o.PrintObj(actual, o.Out); err != nil {//打印结果
    			allErrs = append(allErrs, err)
    		}
    	}
    	return utilerrors.NewAggregate(allErrs)
    }

[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