Allow overriding the bearer token via an authorization header (#1539)

* Allow overriding the bearer token via an authorization header

* Inject apiClient centrally to reduce code duplication

* Dynamically create the resourceVerber in order to allow injecting authentication data

* Added bind-address cli option

* Create kubernetes clientConfig and client dynamically in apihandler

 This makes it easier to properly override the authorization token
 per request.

* Added workaround for broken auth when running in a cluster

* Fixed crash, when config could not be loaded

* Use the request filter chain to inject the apiclient and apiconfig

* Minor cleanup of apihandler.go

- Run of gulp format
- Removed unused parameter
- Moved getting the apiclient/config into a helper function

src/app/backend/client/apiserverclient.go

@@ -56,10 +56,10 @@ func buildConfigFromFlags(masterUrl, kubeconfigPath string) (*rest.Config, error
 //
 // apiserverHost param is in the format of protocol://address:port/pathPrefix, e.g.http://localhost:8001.
 // kubeConfig location of kubeconfig file
-func CreateApiserverClient(apiserverHost string, kubeConfig string) (*kubernetes.Clientset, *rest.Config, error) {
+func CreateApiserverClient(apiserverHost string, kubeConfig string) (*kubernetes.Clientset, error) {
 	cfg, err := buildConfigFromFlags(apiserverHost, kubeConfig)
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 
 	cfg.QPS = defaultQPS
@@ -70,8 +70,8 @@ func CreateApiserverClient(apiserverHost string, kubeConfig string) (*kubernetes
 
 	client, err := kubernetes.NewForConfig(cfg)
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 
-	return client, cfg, nil
+	return client, nil
 }

src/app/backend/dashboard.go

@@ -62,7 +62,7 @@ func main() {
 		log.Printf("Using kubeconfig file: %s", *argKubeConfigFile)
 	}
 
-	apiserverClient, config, err := client.CreateApiserverClient(*argApiserverHost, *argKubeConfigFile)
+	apiserverClient, err := client.CreateApiserverClient(*argApiserverHost, *argKubeConfigFile)
 	if err != nil {
 		handleFatalInitError(err)
 	}
@@ -78,7 +78,9 @@ func main() {
 		log.Printf("Could not create heapster client: %s. Continuing.", err)
 	}
 
-	apiHandler, err := handler.CreateHTTPAPIHandler(apiserverClient, heapsterRESTClient, config)
+	apiHandler, err := handler.CreateHTTPAPIHandler(
+		heapsterRESTClient,
+		handler.ApiClientConfig{ApiserverHost: *argApiserverHost, KubeConfigFile: *argKubeConfigFile})
 	if err != nil {
 		handleFatalInitError(err)
 	}