e2e: change default for --provider

test/e2e/framework/provider.go

@@ -64,11 +64,8 @@ func init() {
 	RegisterProvider("skeleton", func() (ProviderInterface, error) {
 		return NullProvider{}, nil
 	})
-	// The empty string also works, but triggers a warning.
-	RegisterProvider("", func() (ProviderInterface, error) {
-		Logf("The --provider flag is not set.  Treating as a conformance test.  Some tests may not be run.")
-		return NullProvider{}, nil
-	})
+	// The empty string used to be accepted in the past, but is not
+	// a valid value anymore.
 }
 
 // SetupProviderConfig validates the chosen provider and creates

test/e2e/framework/test_context.go

@@ -266,7 +266,7 @@ func RegisterClusterFlags() {
 	flag.StringVar(&TestContext.KubeVolumeDir, "volume-dir", "/var/lib/kubelet", "Path to the directory containing the kubelet volumes.")
 	flag.StringVar(&TestContext.CertDir, "cert-dir", "", "Path to the directory containing the certs. Default is empty, which doesn't use certs.")
 	flag.StringVar(&TestContext.RepoRoot, "repo-root", "../../", "Root directory of kubernetes repository, for finding test files.")
-	flag.StringVar(&TestContext.Provider, "provider", "", "The name of the Kubernetes provider (gce, gke, local, skeleton, etc.)")
+	flag.StringVar(&TestContext.Provider, "provider", "skeleton", "The name of the Kubernetes provider (gce, gke, local, skeleton (the default), etc.)")
 	flag.StringVar(&TestContext.Tooling, "tooling", "", "The tooling in use (kops, gke, etc.)")
 	flag.StringVar(&TestContext.KubectlPath, "kubectl-path", "kubectl", "The kubectl binary to use. For development, you might use 'cluster/kubectl.sh' here.")
 	flag.StringVar(&TestContext.OutputDir, "e2e-output-dir", "/tmp", "Output directory for interesting/useful test data, like performance data, benchmarks, and other metrics.")