adds dynamic certificate reloading for kube aggregator

Co-authored-by: Lukasz Szaszkiewicz <lukasz.szaszkiewicz@gmail.com>
Co-authored-by: David Eads <deads@redhat.com>

cmd/kube-apiserver/app/aggregator.go

@@ -21,7 +21,6 @@ package app
 
 import (
 	"fmt"
-	"io/ioutil"
 	"net/http"
 	"strings"
 	"sync"
@@ -95,28 +94,16 @@ func createAggregatorConfig(
 		return nil, err
 	}
 
-	var certBytes, keyBytes []byte
-	if len(commandOptions.ProxyClientCertFile) > 0 && len(commandOptions.ProxyClientKeyFile) > 0 {
-		certBytes, err = ioutil.ReadFile(commandOptions.ProxyClientCertFile)
-		if err != nil {
-			return nil, err
-		}
-		keyBytes, err = ioutil.ReadFile(commandOptions.ProxyClientKeyFile)
-		if err != nil {
-			return nil, err
-		}
-	}
-
 	aggregatorConfig := &aggregatorapiserver.Config{
 		GenericConfig: &genericapiserver.RecommendedConfig{
 			Config:                genericConfig,
 			SharedInformerFactory: externalInformers,
 		},
 		ExtraConfig: aggregatorapiserver.ExtraConfig{
-			ProxyClientCert: certBytes,
-			ProxyClientKey:  keyBytes,
-			ServiceResolver: serviceResolver,
-			ProxyTransport:  proxyTransport,
+			ProxyClientCertFile: commandOptions.ProxyClientCertFile,
+			ProxyClientKeyFile:  commandOptions.ProxyClientKeyFile,
+			ServiceResolver:     serviceResolver,
+			ProxyTransport:      proxyTransport,
 		},
 	}