e2e: reduce built time for framework

Pulling the CreateKubeConfig function from the expensive to build
test/utils/apiserver package had a considerable impact on the overall build
time because that package depends on a lot of other packages.

Because only that one function is needed by the framework, that extra build
time can be avoided by moving it into its own package.

test/e2e/framework/test_context.go

@@ -39,7 +39,7 @@ import (
 	"k8s.io/klog/v2"
 
 	kubeletconfig "k8s.io/kubernetes/pkg/kubelet/apis/config"
-	testapiserver "k8s.io/kubernetes/test/utils/apiserver"
+	"k8s.io/kubernetes/test/utils/kubeconfig"
 )
 
 const (
@@ -460,7 +460,7 @@ func AfterReadingAllFlags(t *TestContextType) {
 		// Check if we can use the in-cluster config
 		if clusterConfig, err := restclient.InClusterConfig(); err == nil {
 			if tempFile, err := os.CreateTemp(os.TempDir(), "kubeconfig-"); err == nil {
-				kubeConfig := testapiserver.CreateKubeConfig(clusterConfig)
+				kubeConfig := kubeconfig.CreateKubeConfig(clusterConfig)
 				clientcmd.WriteToFile(*kubeConfig, tempFile.Name())
 				t.KubeConfig = tempFile.Name()
 				klog.V(4).Infof("Using a temporary kubeconfig file from in-cluster config : %s", tempFile.Name())

test/utils/apiserver/testapiserver.go

@@ -29,6 +29,7 @@ import (
 	"k8s.io/client-go/tools/clientcmd"
 	"k8s.io/client-go/util/cert"
 	kubeapiservertesting "k8s.io/kubernetes/cmd/kube-apiserver/app/testing"
+	"k8s.io/kubernetes/test/utils/kubeconfig"
 )
 
 // TestAPIServer provides access to a running apiserver instance.
@@ -90,7 +91,7 @@ func writeKubeConfigForWardleServerToKASConnection(t *testing.T, kubeClientConfi
 		t.Logf("CA bundle %v\n", dynamiccertificates.GetHumanCertDetail(curr))
 	}
 
-	adminKubeConfig := CreateKubeConfig(wardleToKASKubeClientConfig)
+	adminKubeConfig := kubeconfig.CreateKubeConfig(wardleToKASKubeClientConfig)
 	tmpDir := t.TempDir()
 	kubeConfigFile := path.Join(tmpDir, "kube.config")
 	if err := clientcmd.WriteToFile(*adminKubeConfig, kubeConfigFile); err != nil {

test/utils/kubeconfig/kubeconfig.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package apiserver
+package kubeconfig
 
 import (
 	"k8s.io/client-go/rest"