云原生｜k8s api-server代码了解

func main() {
  command := app.NewAPIServerCommand()
  code := cli.Run(command)
  os.Exit(code)
}

func Run(completeOptions completedServerRunOptions, stopCh <-chan struct{}) error {
// To help debugging, immediately log version

klog.Infof("Version: %+v", version.Get())
klog.InfoS("Golang settings", "GOGC", os.Getenv("GOGC"), "GOMAXPROCS", os.Getenv("GOMAXPROCS"), "GOTRACEBACK", os.Getenv("GOTRACEBACK"))
server, err := CreateServerChain(completeOptions)

if err != nil {

return err

}
prepared, err := server.PrepareRun()

if err != nil {

return err

}
return prepared.Run(stopCh)

}

// CreateServerChain creates the apiservers connected via delegation.

func CreateServerChain(completedOptions completedServerRunOptions) (*aggregatorapiserver.APIAggregator, error) {

kubeAPIServerConfig, serviceResolver, pluginInitializer, err := CreateKubeAPIServerConfig(completedOptions)

if err != nil {

return nil, err

}

// If additional API servers are added, they should be gated.

apiExtensionsConfig, err := createAPIExtensionsConfig(*kubeAPIServerConfig.GenericConfig, kubeAPIServerConfig.ExtraConfig.VersionedInformers, pluginInitializer, completedOptions.ServerRunOptions, completedOptions.MasterCount,

serviceResolver, webhook.NewDefaultAuthenticationInfoResolverWrapper(kubeAPIServerConfig.ExtraConfig.ProxyTransport, kubeAPIServerConfig.GenericConfig.EgressSelector, kubeAPIServerConfig.GenericConfig.LoopbackClientConfig, kubeAPIServerConfig.GenericConfig.TracerProvider))

if err != nil {

return nil, err

}
notFoundHandler := notfoundhandler.New(kubeAPIServerConfig.GenericConfig.Serializer, genericapifilters.NoMuxAndDiscoveryIncompleteKey)

apiExtensionsServer, err := createAPIExtensionsServer(apiExtensionsConfig, genericapiserver.NewEmptyDelegateWithCustomHandler(notFoundHandler))

if err != nil {

return nil, err

}
kubeAPIServer, err := CreateKubeAPIServer(kubeAPIServerConfig, apiExtensionsServer.GenericAPIServer)

if err != nil {

return nil, err

}
// aggregator comes last in the chain

aggregatorConfig, err := createAggregatorConfig(*kubeAPIServerConfig.GenericConfig, completedOptions.ServerRunOptions, kubeAPIServerConfig.ExtraConfig.VersionedInformers, serviceResolver, kubeAPIServerConfig.ExtraConfig.ProxyTransport, pluginInitializer)

if err != nil {

return nil, err

}

aggregatorServer, err := createAggregatorServer(aggregatorConfig, kubeAPIServer.GenericAPIServer, apiExtensionsServer.Informers)

if err != nil {

// we don't need special handling for innerStopCh because the aggregator server doesn't create any go routines

return nil, err

}
return aggregatorServer, nil

}