Cleanup some low-hanging fruits and review TODOs

cmd/kubeadm/kubeadm.go

@@ -17,14 +17,16 @@ limitations under the License.
 package main
 
 import (
+	"fmt"
 	"os"
 
 	"k8s.io/kubernetes/cmd/kubeadm/app"
 )
 
-// TODO(phase1): check for root
+// TODO(phase1+): check for root
 func main() {
 	if err := app.Run(); err != nil {
+		fmt.Printf(app.AlphaWarningOnExit)
 		os.Exit(1)
 	}
 	os.Exit(0)