// 類似kubectl的源代碼，kube-apiserver的命令行工具也使用了cobra，我們很快就能找到啟動(dòng)的入口
RunE: func(cmd *cobra.Command, args []string) error {
			// 這里包含2個(gè)參數(shù)，前者是參數(shù)completedOptions，后者是一個(gè)stopCh <-chan struct{}
			return Run(completedOptions, genericapiserver.SetupSignalHandler())
		}
/*
	在這里，我們可以和kubectl結(jié)合起來(lái)思考：
	kubectl是一個(gè)命令行工具，執(zhí)行完命令就退出；kube-apiserver是一個(gè)常駐的服務(wù)器進(jìn)程，監(jiān)聽(tīng)端口
	這里引入了一個(gè)stopCh <-chan struct{}，可以在啟動(dòng)后，用一個(gè) <-stopCh 作為阻塞，使程序不退出
	用channel阻塞進(jìn)程退出，對(duì)比傳統(tǒng)的方法 - 用一個(gè)永不退出的for循環(huán)，是一個(gè)很優(yōu)雅的實(shí)現(xiàn)
*/
func Run(completeOptions completedServerRunOptions, stopCh <-chan struct{}) error {
        // 這里進(jìn)行創(chuàng)建服務(wù)鏈
        server, err := CreateServerChain(completeOptions)
	if err != nil {
		return err
	}
	prepared, err := server.PrepareRun()
	if err != nil {
		return err
	}
	return prepared.Run(stopCh)
}

// 在CreateServerChain這個(gè)函數(shù)下，創(chuàng)建了3個(gè)server 
func CreateServerChain(){
  // API擴(kuò)展服務(wù)，主要針對(duì)CRD
	createAPIExtensionsServer(){} 
  // API核心服務(wù)，包括常見(jiàn)的Pod/Deployment/Service，我們今天的重點(diǎn)聚焦在這里
  // 我會(huì)跳過(guò)很多非核心的配置參數(shù)，一開(kāi)始就去研究細(xì)節(jié)，很影響整體代碼的閱讀效率
	CreateKubeAPIServer(){} 
  // API聚合服務(wù)，主要針對(duì)metrics
	createAggregatorServer(){} 
  //細(xì)節(jié)是第二個(gè)ApiServer需要第一個(gè)server的配置，第三個(gè)server會(huì)要第二個(gè)server的配置，最后返回的是聚合server
  // 這些server的config都是由一個(gè)GenericConfig和一個(gè)ExtraConfig組成 有自己的特點(diǎn)和鏈上的
      return aggregatorServer, nil
}

// 創(chuàng)建配置的流程
func CreateKubeAPIServerConfig(){
  // 創(chuàng)建通用配置genericConfig
  genericConfig, versionedInformers, insecureServingInfo, serviceResolver, pluginInitializers, admissionPostStartHook, storageFactory, err := buildGenericConfig(s.ServerRunOptions, proxyTransport)
}

// 通用配置的創(chuàng)建
func buildGenericConfig(s *options.ServerRunOptions,proxyTransport *http.Transport){
  // Insecure對(duì)應(yīng)的非安全的通信，也就是HTTP
  if lastErr = s.InsecureServing...
  // Secure對(duì)應(yīng)的就是HTTPS
  if lastErr = s.SecureServing...
  // OpenAPIConfig是對(duì)外提供的API文檔
  genericConfig.OpenAPIConfig = genericapiserver.DefaultOpenAPIConfig()
  // 這一塊是storageFactory的實(shí)例化，可以看到采用的是etcd作為存儲(chǔ)方案
  storageFactoryConfig := kubeapiserver.NewStorageFactoryConfig()
	storageFactoryConfig.APIResourceConfig = genericConfig.MergedResourceConfig
	completedStorageFactoryConfig, err := storageFactoryConfig.Complete(s.Etcd)
	storageFactory, lastErr = completedStorageFactoryConfig.New()
  // Authentication 認(rèn)證相關(guān)
  if lastErr = s.Authentication.ApplyTo()...
  // Authorization 授權(quán)相關(guān)
  genericConfig.Authorization.Authorizer, genericConfig.RuleResolver, err = BuildAuthorizer()
  // Admission 準(zhǔn)入機(jī)制
  err = s.Admission.ApplyTo()
}

func (o *BuiltInAuthenticationOptions) ApplyTo(){
  // 前面都是對(duì)認(rèn)證config進(jìn)行參數(shù)設(shè)置，這里才是真正的實(shí)例化
  authInfo.Authenticator, openAPIConfig.SecurityDefinitions, err = authenticatorConfig.New()
}
// New這塊的代碼，我們要抓住核心變量authenticators和tokenAuthenticators，也就是各種認(rèn)證方法
func (config Config) New() (authenticator.Request, *spec.SecurityDefinitions, error) {
  // 核心變量authenticators和tokenAuthenticators
	var authenticators []authenticator.Request
        var tokenAuthenticators []authenticator.Token
	if config.RequestHeaderConfig != nil {
		// 1. 添加requestHeader
		authenticators = append(authenticators, authenticator.WrapAudienceAgnosticRequest(config.APIAudiences, requestHeaderAuthenticator))
	}
	if config.ClientCAContentProvider != nil {
		// 2. 添加ClientCA
    authenticators = append(authenticators, certAuth)
	}
	if len(config.TokenAuthFile) > 0 {
		// 3. token 添加tokenfile
		tokenAuthenticators = append(tokenAuthenticators, authenticator.WrapAudienceAgnosticToken(config.APIAudiences, tokenAuth))
	}
  // 4. token 添加 service account，分兩種來(lái)源
	if len(config.ServiceAccountKeyFiles) > 0 {
		tokenAuthenticators = append(tokenAuthenticators, serviceAccountAuth)
	}
	if utilfeature.DefaultFeatureGate.Enabled(features.TokenRequest) && config.ServiceAccountIssuer != "" {
		tokenAuthenticators = append(tokenAuthenticators, serviceAccountAuth)
	}
	if config.BootstrapToken {
		if config.BootstrapTokenAuthenticator != nil {
      // 5. token 添加 bootstrap
			tokenAuthenticators = append(tokenAuthenticators, authenticator.WrapAudienceAgnosticToken(config.APIAudiences, config.BootstrapTokenAuthenticator))
		}
	}
	if len(config.OIDCIssuerURL) > 0 && len(config.OIDCClientID) > 0 {
		// 6. token 添加 oidc
    Authenticators = append(tokenAuthenticators, authenticator.WrapAudienceAgnosticToken(config.APIAudiences, oidcAuth))
	}
	if len(config.WebhookTokenAuthnConfigFile) > 0 {
		// 7. token 添加 webhook
		tokenAuthenticators = append(tokenAuthenticators, webhookTokenAuth)
	}
  // 8. 組合tokenAuthenticators到tokenAuthenticators中
	if len(tokenAuthenticators) > 0 {
		tokenAuth := tokenunion.New(tokenAuthenticators...)
		if config.TokenSuccessCacheTTL > 0 || config.TokenFailureCacheTTL > 0 {
			tokenAuth = tokencache.New(tokenAuth, true, config.TokenSuccessCacheTTL, config.TokenFailureCacheTTL)
		}
		authenticators = append(authenticators, bearertoken.New(tokenAuth), websocket.NewProtocolAuthenticator(tokenAuth))
	}
  // 9. 沒(méi)有任何認(rèn)證方式且啟用了Anonymous
	if len(authenticators) == 0 {
		if config.Anonymous {
			return anonymous.NewAuthenticator(), &securityDefinitions, nil
		}
		return nil, &securityDefinitions, nil
	}
  // 10. 組合authenticators
	authenticator := union.New(authenticators...)
	return authenticator, &securityDefinitions, nil
}

func BuildAuthorizer(){
  // 與上面一致，實(shí)例化是在這個(gè)New中
  return authorizationConfig.New()
}
// 不得不說(shuō)，Authorizer這塊的閱讀體驗(yàn)更好
func (config Config) New() (authorizer.Authorizer, authorizer.RuleResolver, error) {
  // 必須傳入一個(gè)Authorizer機(jī)制
	if len(config.AuthorizationModes) == 0 {
		return nil, nil, fmt.Errorf("at least one authorization mode must be passed")
	}
	var (
		authorizers   []authorizer.Authorizer
		ruleResolvers []authorizer.RuleResolver
	)
	for _, authorizationMode := range config.AuthorizationModes {
		// 具體的mode定義，可以跳轉(zhuǎn)到對(duì)應(yīng)的鏈接去看，不細(xì)講
		switch authorizationMode {
		case modes.ModeNode:
			authorizers = append(authorizers, nodeAuthorizer)
			ruleResolvers = append(ruleResolvers, nodeAuthorizer)
		case modes.ModeAlwaysAllow:
			authorizers = append(authorizers, alwaysAllowAuthorizer)
			ruleResolvers = append(ruleResolvers, alwaysAllowAuthorizer)
		case modes.ModeAlwaysDeny:
			authorizers = append(authorizers, alwaysDenyAuthorizer)
			ruleResolvers = append(ruleResolvers, alwaysDenyAuthorizer)
		case modes.ModeABAC:
			authorizers = append(authorizers, abacAuthorizer)
			ruleResolvers = append(ruleResolvers, abacAuthorizer)
		case modes.ModeWebhook:
			authorizers = append(authorizers, webhookAuthorizer)
			ruleResolvers = append(ruleResolvers, webhookAuthorizer)
		case modes.ModeRBAC:
			authorizers = append(authorizers, rbacAuthorizer)
			ruleResolvers = append(ruleResolvers, rbacAuthorizer)
		default:
			return nil, nil, fmt.Errorf("unknown authorization mode %s specified", authorizationMode)
		}
	}
	return union.New(authorizers...), union.NewRuleResolvers(ruleResolvers...), nil
}
const (
	// ModeAlwaysAllow is the mode to set all requests as authorized
	ModeAlwaysAllow string = "AlwaysAllow"
	// ModeAlwaysDeny is the mode to set no requests as authorized
	ModeAlwaysDeny string = "AlwaysDeny"
	// ModeABAC is the mode to use Attribute Based Access Control to authorize
	ModeABAC string = "ABAC"
	// ModeWebhook is the mode to make an external webhook call to authorize
	ModeWebhook string = "Webhook"
	// ModeRBAC is the mode to use Role Based Access Control to authorize
	ModeRBAC string = "RBAC"
	// ModeNode is an authorization mode that authorizes API requests made by kubelets.
	ModeNode string = "Node"
)

// 查看定義
err = s.Admission.ApplyTo()
func (a *AdmissionOptions) ApplyTo(){
  return a.GenericAdmission.ApplyTo()
}
func (ps *Plugins) NewFromPlugins(){
  for _, pluginName := range pluginNames {
		// InitPlugin 為初始化的工作
		plugin, err := ps.InitPlugin(pluginName, pluginConfig, pluginInitializer)
		if err != nil {
			return nil, err
		}
	}
}
func (ps *Plugins) InitPlugin(name string, config io.Reader, pluginInitializer PluginInitializer) (Interface, error){
  // 獲取plugin
  plugin, found, err := ps.getPlugin(name, config)
}
// 查看一下Interface的定義，就是對(duì)準(zhǔn)入機(jī)制的控制 抽象化的插件化的接口 服務(wù)于Admission Control
// Interface is an abstract, pluggable interface for Admission Control decisions.
type Interface interface {
	Handles(operation Operation) bool
}
// 再去看看獲取plugin的地方
func (ps *Plugins) getPlugin(name string, config io.Reader) (Interface, bool, error) {
	ps.lock.Lock()
	defer ps.lock.Unlock()
  // 我們?cè)偃パ芯縫s.registry這個(gè)參數(shù)是在哪里被初始化的
	f, found := ps.registry[name]
}
// 接下來(lái)，我們從kube-apiserver啟動(dòng)過(guò)程，逐步找到Admission被初始化的地方
// 啟動(dòng)命令
command := app.NewAPIServerCommand()
// server配置
s := options.NewServerRunOptions()
// admission選項(xiàng)
Admission:               kubeoptions.NewAdmissionOptions()
// 注冊(cè)準(zhǔn)入機(jī)制
RegisterAllAdmissionPlugins(options.Plugins)
// 準(zhǔn)入機(jī)制的所有內(nèi)容
func RegisterAllAdmissionPlugins(plugins *admission.Plugins){
  // 這里有很多plugin的注冊(cè)
}
// 往上翻，我們能找到所有plugin，也就是準(zhǔn)入機(jī)制的定義 有三十幾種 已經(jīng)進(jìn)行了排序的
var AllOrderedPlugins = []string{
admit.PluginName,                        // AlwaysAdmit
	autoprovision.PluginName,                // NamespaceAutoProvision
	lifecycle.PluginName,                    // NamespaceLifecycle
	exists.PluginName,                       // NamespaceExists
	scdeny.PluginName,                       // SecurityContextDeny
	antiaffinity.PluginName,                 // LimitPodHardAntiAffinityTopology
	limitranger.PluginName,                  // LimitRanger
	serviceaccount.PluginName,               // ServiceAccount
	noderestriction.PluginName,              // NodeRestriction
	nodetaint.PluginName,                    // TaintNodesByCondition
	alwayspullimages.PluginName,             // AlwaysPullImages
	imagepolicy.PluginName,                  // ImagePolicyWebhook
	podsecurity.PluginName,                  // PodSecurity
	podnodeselector.PluginName,              // PodNodeSelector
	podpriority.PluginName,                  // Priority
	defaulttolerationseconds.PluginName,     // DefaultTolerationSeconds
	podtolerationrestriction.PluginName,     // PodTolerationRestriction
	eventratelimit.PluginName,               // EventRateLimit
	extendedresourcetoleration.PluginName,   // ExtendedResourceToleration
	label.PluginName,                        // PersistentVolumeLabel
	setdefault.PluginName,                   // DefaultStorageClass
	storageobjectinuseprotection.PluginName, // StorageObjectInUseProtection
	gc.PluginName,                           // OwnerReferencesPermissionEnforcement
	resize.PluginName,                       // PersistentVolumeClaimResize
	runtimeclass.PluginName,                 // RuntimeClass
	certapproval.PluginName,                 // CertificateApproval
	certsigning.PluginName,                  // CertificateSigning
	certsubjectrestriction.PluginName,       // CertificateSubjectRestriction
	defaultingressclass.PluginName,          // DefaultIngressClass
	denyserviceexternalips.PluginName,       // DenyServiceExternalIPs
	// new admission plugins should generally be inserted above here
	// webhook, resourcequota, and deny plugins must go at the end
	mutatingwebhook.PluginName,   // MutatingAdmissionWebhook
	validatingwebhook.PluginName, // ValidatingAdmissionWebhook
	resourcequota.PluginName,     // ResourceQuota
	deny.PluginName,              // AlwaysDeny
}

// 先對(duì)配置進(jìn)行complete補(bǔ)全再進(jìn)行new
func CreateKubeAPIServer(kubeAPIServerConfig *controlplane.Config, delegateAPIServer genericapiserver.DelegationTarget) (*controlplane.Instance, error) {
	kubeAPIServer, err := kubeAPIServerConfig.Complete().New(delegateAPIServer)
	if err != nil {
		return nil, err
	}
	return kubeAPIServer, nil
}

// 在APIExtensionsServer、KubeAPIServer和AggregatorServer三種Server啟動(dòng)時(shí)，我們都能發(fā)現(xiàn)這么一個(gè)函數(shù)
// APIExtensionsServer
genericServer, err := c.GenericConfig.New("apiextensions-apiserver", delegationTarget)
// KubeAPIServer
s, err := c.GenericConfig.New("kube-apiserver", delegationTarget)
// AggregatorServer
genericServer, err := c.GenericConfig.New("kube-aggregator", delegationTarget)
// 都通過(guò)GenericConfig創(chuàng)建了genericServer，我們先大致瀏覽下
func (c completedConfig) New(name string, delegationTarget DelegationTarget) (*GenericAPIServer, error) {
	// 新建Handler
	apiServerHandler := NewAPIServerHandler(name, c.Serializer, handlerChainBuilder, delegationTarget.UnprotectedHandler())
	// 實(shí)例化一個(gè)Server
	s := &GenericAPIServer{
    ...
  }
	// 處理鉤子hook操作
	for k, v := range delegationTarget.PostStartHooks() {
		s.postStartHooks[k] = v
	}
	for k, v := range delegationTarget.PreShutdownHooks() {
		s.preShutdownHooks[k] = v
	}
	// 健康監(jiān)測(cè)
	for _, delegateCheck := range delegationTarget.HealthzChecks() {
		skip := false
		for _, existingCheck := range c.HealthzChecks {
			if existingCheck.Name() == delegateCheck.Name() {
				skip = true
				break
			}
		}
		if skip {
			continue
		}
		s.AddHealthChecks(delegateCheck)
	}
  // 安裝API相關(guān)參數(shù)，這個(gè)是重點(diǎn)
	installAPI(s, c.Config)
	return s, nil
}

func NewAPIServerHandler(name string, s runtime.NegotiatedSerializer, handlerChainBuilder HandlerChainBuilderFn, notFoundHandler http.Handler) *APIServerHandler {
	// 采用了 github.com/emicklei/go-restful 這個(gè)庫(kù)作為 RESTful 接口的設(shè)計(jì)，目前了解即可
	gorestfulContainer := restful.NewContainer()
}

func installAPI(s *GenericAPIServer, c *Config) {
  // 添加 /index.html 路由規(guī)則
	if c.EnableIndex {
		routes.Index{}.Install(s.listedPathProvider, s.Handler.NonGoRestfulMux)
	}
  // 添加go語(yǔ)言 /pprof 的路由規(guī)則，常用于性能分析
	if c.EnableProfiling {
		routes.Profiling{}.Install(s.Handler.NonGoRestfulMux)
		if c.EnableContentionProfiling {
			goruntime.SetBlockProfileRate(1)
		}
		routes.DebugFlags{}.Install(s.Handler.NonGoRestfulMux, "v", routes.StringFlagPutHandler(logs.GlogSetter))
	}
  // 添加監(jiān)控相關(guān)的 /metrics 的指標(biāo)路由規(guī)則
	if c.EnableMetrics {
		if c.EnableProfiling {
			routes.MetricsWithReset{}.Install(s.Handler.NonGoRestfulMux)
		} else {
			routes.DefaultMetrics{}.Install(s.Handler.NonGoRestfulMux)
		}
	}
	// 添加版本 /version 的路由規(guī)則
	routes.Version{Version: c.Version}.Install(s.Handler.GoRestfulContainer)
	// 開(kāi)啟服務(wù)發(fā)現(xiàn)
	if c.EnableDiscovery {
		s.Handler.GoRestfulContainer.Add(s.DiscoveryGroupManager.WebService())
	}
	if feature.DefaultFeatureGate.Enabled(features.APIPriorityAndFairness) {
		c.FlowControl.Install(s.Handler.NonGoRestfulMux)
	}
}

func (c completedConfig) New(delegationTarget genericapiserver.DelegationTarget) (*Master, error) {
	// genericServer的初始化
	s, err := c.GenericConfig.New("kube-apiserver", delegationTarget)
	// 核心KubeAPIServer的實(shí)例化
	m := &Master{
		GenericAPIServer:          s,
		ClusterAuthenticationInfo: c.ExtraConfig.ClusterAuthenticationInfo,
	}
	// 注冊(cè)Legacy API的注冊(cè)
	if c.ExtraConfig.APIResourceConfigSource.VersionEnabled(apiv1.SchemeGroupVersion) {
		legacyRESTStorageProvider := corerest.LegacyRESTStorageProvider{}
		if err := m.InstallLegacyAPI(&c, c.GenericConfig.RESTOptionsGetter, legacyRESTStorageProvider); err != nil {
			return nil, err
		}
	}
	// REST接口的存儲(chǔ)定義，可以看到很多k8s上的常見(jiàn)定義，比如node節(jié)點(diǎn)/storage存儲(chǔ)/event事件等等
	restStorageProviders := []RESTStorageProvider{
		authenticationrest.RESTStorageProvider{Authenticator: c.GenericConfig.Authentication.Authenticator, APIAudiences: c.GenericConfig.Authentication.APIAudiences},
		authorizationrest.RESTStorageProvider{Authorizer: c.GenericConfig.Authorization.Authorizer, RuleResolver: c.GenericConfig.RuleResolver},
		autoscalingrest.RESTStorageProvider{},
		batchrest.RESTStorageProvider{},
		certificatesrest.RESTStorageProvider{},
		coordinationrest.RESTStorageProvider{},
		discoveryrest.StorageProvider{},
		extensionsrest.RESTStorageProvider{},
		networkingrest.RESTStorageProvider{},
		noderest.RESTStorageProvider{},
		policyrest.RESTStorageProvider{},
		rbacrest.RESTStorageProvider{Authorizer: c.GenericConfig.Authorization.Authorizer},
		schedulingrest.RESTStorageProvider{},
		settingsrest.RESTStorageProvider{},
		storagerest.RESTStorageProvider{},
		flowcontrolrest.RESTStorageProvider{},
		// keep apps after extensions so legacy clients resolve the extensions versions of shared resource names.
		// See https://github.com/kubernetes/kubernetes/issues/42392
		appsrest.StorageProvider{},
		admissionregistrationrest.RESTStorageProvider{},
		eventsrest.RESTStorageProvider{TTL: c.ExtraConfig.EventTTL},
	}
  // 注冊(cè)API
	if err := m.InstallAPIs(c.ExtraConfig.APIResourceConfigSource, c.GenericConfig.RESTOptionsGetter, restStorageProviders...); err != nil {
		return nil, err
	}
	// 添加Hook
	m.GenericAPIServer.AddPostStartHookOrDie("start-cluster-authentication-info-controller", func(hookContext genericapiserver.PostStartHookContext) error {
	})
	return m, nil
}

// 定義了legacy和非legacy資源的路由前綴
const (
// DefaultLegacyAPIPrefix is where the legacy APIs will be located.
DefaultLegacyAPIPrefix="/api"
// APTGroupPrefix is where non-legacy API group will be located.
APIGroupPrefix ="/apis"
)
func (m *Master) InstallLegacyAPI(c *completedConfig, restOptionsGetter generic.RESTOptionsGetter, legacyRESTStorageProvider corerest.LegacyRESTStorageProvider) error {
  // RESTStorage的初始化
	legacyRESTStorage, apiGroupInfo, err := legacyRESTStorageProvider.NewLegacyRESTStorage(restOptionsGetter)
  // 前綴為 /api，注冊(cè)上對(duì)應(yīng)的Version和Resource
  // Pod作為核心資源，沒(méi)有Group的概念
	if err := m.GenericAPIServer.InstallLegacyAPIGroup(genericapiserver.DefaultLegacyAPIPrefix, &apiGroupInfo); err != nil {
		return fmt.Errorf("error in registering group versions: %v", err)
	}
	return nil
}
// 我們?cè)偌?xì)看這個(gè)RESTStorage的初始化
func (c LegacyRESTStorageProvider) NewLegacyRESTStorage(restOptionsGetter generic.RESTOptionsGetter) (LegacyRESTStorage, genericapiserver.APIGroupInfo, error) {
	// pod 模板
	podTemplateStorage, err := podtemplatestore.NewREST(restOptionsGetter)
	// event事件
	eventStorage, err := eventstore.NewREST(restOptionsGetter, uint64(c.EventTTL.Seconds()))
	// limitRange資源限制
	limitRangeStorage, err := limitrangestore.NewREST(restOptionsGetter)
	// resourceQuota資源配額
	resourceQuotaStorage, resourceQuotaStatusStorage, err := resourcequotastore.NewREST(restOptionsGetter)
	// secret加密
	secretStorage, err := secretstore.NewREST(restOptionsGetter)
	// PV 存儲(chǔ)
	persistentVolumeStorage, persistentVolumeStatusStorage, err := pvstore.NewREST(restOptionsGetter)
	// PVC 存儲(chǔ)
	persistentVolumeClaimStorage, persistentVolumeClaimStatusStorage, err := pvcstore.NewREST(restOptionsGetter)
	// ConfigMap 配置
	configMapStorage, err := configmapstore.NewREST(restOptionsGetter)
	// 等等核心資源，暫不一一列舉
  // pod模板，我們的示例nginx-pod屬于這個(gè)類型的資源
  podStorage, err := podstore.NewStorage()
  // 保存storage的對(duì)應(yīng)關(guān)系
  restStorageMap := map[string]rest.Storage{
		"pods":             podStorage.Pod,
		"pods/attach":      podStorage.Attach,
		"pods/status":      podStorage.Status,
		"pods/log":         podStorage.Log,
		"pods/exec":        podStorage.Exec,
		"pods/portforward": podStorage.PortForward,
		"pods/proxy":       podStorage.Proxy,
		"pods/binding":     podStorage.Binding,
		"bindings":         podStorage.LegacyBinding,
    ...
  }
}

// 查看Pod初始化 上一步的podStorage
func NewStorage(optsGetter generic.RESTOptionsGetter, k client.ConnectionInfoGetter, proxyTransport http.RoundTripper, podDisruptionBudgetClient policyclient.PodDisruptionBudgetsGetter) (PodStorage, error) {
	store := &genericregistry.Store{
		NewFunc:                  func() runtime.Object { return &api.Pod{} },
		NewListFunc:              func() runtime.Object { return &api.PodList{} },
		PredicateFunc:            registrypod.MatchPod,
		DefaultQualifiedResource: api.Resource("pods"),
		// 增改刪的策略
		CreateStrategy:      registrypod.Strategy,
		UpdateStrategy:      registrypod.Strategy,
		DeleteStrategy:      registrypod.Strategy,
		ReturnDeletedObject: true,
		TableConvertor: printerstorage.TableConvertor{TableGenerator: printers.NewTableGenerator().With(printersinternal.AddHandlers)},
	}
}
// 查看 Strategy 的初始化 是一個(gè)全局變量  進(jìn)行實(shí)例化 調(diào)用了Scheme，核心資源的schme，legacyscheme
var Strategy = podStrategy{legacyscheme.Scheme, names.SimpleNameGenerator}
// 又查詢到Scheme的初始化。Schema可以理解為Kubernetes的注冊(cè)表，即所有的資源類型必須先注冊(cè)進(jìn)Schema才可使用 注冊(cè)里有資源的增刪改的策略
var Scheme = runtime.NewScheme()

// podStrategy 是封裝了 Pod 的各類動(dòng)作，這里我們先關(guān)注create這個(gè)操作
type podStrategy struct {
	runtime.ObjectTyper
	names.NameGenerator
}
// podStrategy 的接口
type RESTCreateStrategy interface {
	runtime.ObjectTyper
	names.NameGenerator
  // 是否屬于當(dāng)前的 namespace
	NamespaceScoped() bool
  // 準(zhǔn)備創(chuàng)建前的檢查
	PrepareForCreate(ctx context.Context, obj runtime.Object)
  // 驗(yàn)證資源對(duì)象
	Validate(ctx context.Context, obj runtime.Object) field.ErrorList
  // 規(guī)范化
	Canonicalize(obj runtime.Object)
}
// 完成了檢查，我們就要保存數(shù)據(jù)了

// PodStorage 是 Pod 存儲(chǔ)的實(shí)現(xiàn)，里面包含了多個(gè)存儲(chǔ)的定義
type PodStorage struct {
  // REST implements a RESTStorage for pods
	Pod                 *REST
  // BindingREST implements the REST endpoint for binding pods to nodes when etcd is in use.
	Binding             *BindingREST
  // LegacyBindingREST implements the REST endpoint for binding pods to nodes when etcd is in use.
	LegacyBinding       *LegacyBindingREST
	Eviction            *EvictionREST
  // StatusREST implements the REST endpoint for changing the status of a pod.
	Status              *StatusREST
  // EphemeralContainersREST implements the REST endpoint for adding EphemeralContainers
	EphemeralContainers *EphemeralContainersREST
	Log                 *podrest.LogREST
	Proxy               *podrest.ProxyREST
	Exec                *podrest.ExecREST
	Attach              *podrest.AttachREST
	PortForward         *podrest.PortForwardREST
}
/*
從上一節(jié)的map關(guān)系中，保存在REST中
restStorageMap := map[string]rest.Storage{
		"pods":             podStorage.Pod,
}
*/
type REST struct {
	*genericregistry.Store
        // 代理傳輸層 大概率是和網(wǎng)絡(luò)相關(guān)的先不看
	proxyTransport http.RoundTripper
}
// Store是一個(gè)通用的數(shù)據(jù)結(jié)構(gòu)
type Store struct {
	// Storage定義
        ...
	Storage DryRunnableStorage
}
// DryRunnableStorage中的Storage是一個(gè)Interface
type DryRunnableStorage struct {
	Storage storage.Interface
        // 和編解碼相關(guān)的codec          
	Codec   runtime.Codec
}
func (s *DryRunnableStorage) Create(ctx context.Context, key string, obj, out runtime.Object, ttl uint64, dryRun bool) error {
	if dryRun {
		if err := s.Storage.Get(ctx, key, storage.GetOptions{}, out); err == nil {
			return storage.NewKeyExistsError(key, 0)
		}
		return s.copyInto(obj, out)
	}
  // 這里，就是Create的真正調(diào)用
	return s.Storage.Create(ctx, key, obj, out, ttl)
}

// Storage Interface 的定義，包括基本的增刪改查，以及watch等等進(jìn)階操作
type Interface interface {
	Versioner() Versioner
	Create(ctx context.Context, key string, obj, out runtime.Object, ttl uint64) error
	Delete(ctx context.Context, key string, out runtime.Object, preconditions *Preconditions, validateDeletion ValidateObjectFunc) error
	Watch(ctx context.Context, key string, opts ListOptions) (watch.Interface, error)
	WatchList(ctx context.Context, key string, opts ListOptions) (watch.Interface, error)
	Get(ctx context.Context, key string, opts GetOptions, objPtr runtime.Object) error
	GetToList(ctx context.Context, key string, opts ListOptions, listObj runtime.Object) error
	List(ctx context.Context, key string, opts ListOptions, listObj runtime.Object) error
	GuaranteedUpdate(
		ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool,
		precondtions *Preconditions, tryUpdate UpdateFunc, suggestion ...runtime.Object) error
	Count(key string) (int64, error)
}
// 去找Storage的初始化
func NewRawStorage(config *storagebackend.Config) (storage.Interface, factory.DestroyFunc, error) {
	return factory.Create(*config)
}
func Create(c storagebackend.Config) (storage.Interface, DestroyFunc, error) {
	switch c.Type {
  // 已經(jīng)不支持etcd2
	case "etcd2":
		return nil, nil, fmt.Errorf("%v is no longer a supported storage backend", c.Type)
  // 默認(rèn)為etcd3版本
	case storagebackend.StorageTypeUnset, storagebackend.StorageTypeETCD3:
		return newETCD3Storage(c)
	default:
		return nil, nil, fmt.Errorf("unknown storage type: %s", c.Type)
	}
}