Fix GetPodLogs failures in NetworkPolicy e2e tests

GetPodLogs always fails when the tests fail, which is because the tests
specify wrong container names when getting logs.

When creating a client Pod, it specifies "<podName>-container" as
container name and "<podName>-" as Pod GenerateName. For instance,
podName "client-a" will result in "client-a-container" as the container
name and "client-a-vx5sv" as the actual Pod name, but it always uses the
actual Pod name to construct the container name when getting logs, e.g.
"client-a-vx5sv-container".

This patch fixes it by specifying the same static container name when
creating Pod and getting logs.

Author: tnqn

test/e2e/network/network_policy.go

@@ -1415,7 +1415,7 @@ func checkConnectivity(f *framework.Framework, ns *v1.Namespace, podClient *v1.P
 	err = e2epod.WaitForPodSuccessInNamespace(f.ClientSet, podClient.Name, ns.Name)
 	if err != nil {
 		// Collect pod logs when we see a failure.
-		logs, logErr := e2epod.GetPodLogs(f.ClientSet, f.Namespace.Name, podClient.Name, fmt.Sprintf("%s-container", podClient.Name))
+		logs, logErr := e2epod.GetPodLogs(f.ClientSet, f.Namespace.Name, podClient.Name, "client")
 		if logErr != nil {
 			framework.Failf("Error getting container logs: %s", logErr)
 		}
@@ -1452,7 +1452,7 @@ func checkNoConnectivity(f *framework.Framework, ns *v1.Namespace, podClient *v1
 	// Dump debug information if the error was nil.
 	if err == nil {
 		// Collect pod logs when we see a failure.
-		logs, logErr := e2epod.GetPodLogs(f.ClientSet, f.Namespace.Name, podClient.Name, fmt.Sprintf("%s-container", podClient.Name))
+		logs, logErr := e2epod.GetPodLogs(f.ClientSet, f.Namespace.Name, podClient.Name, "client")
 		if logErr != nil {
 			framework.Failf("Error getting container logs: %s", logErr)
 		}
@@ -1589,7 +1589,7 @@ func createNetworkClientPod(f *framework.Framework, namespace *v1.Namespace, pod
 			RestartPolicy: v1.RestartPolicyNever,
 			Containers: []v1.Container{
 				{
-					Name:  fmt.Sprintf("%s-container", podName),
+					Name:  "client",
 					Image: imageutils.GetE2EImage(imageutils.BusyBox),
 					Args: []string{
 						"/bin/sh",