Limiting the scope of new kubectl get e2e tests to decrease flakiness

The `kubectl get output` e2e test I'd previously added ended up being
flaky in certain e2e test scenarios. It relies on getting a list of API
resources in the cluster and running `kubectl get` calls against them.
The problem ended up being that other e2e tests could create resources
that would cause this test to fail. This change limits the scope of the
tests to not cover CRDs. This should still allow the test to catch new
Kubernetes resources with improperly configured kubectl output while
limiting the flakiness of the test.

Author: robscott

test/e2e/kubectl/kubectl.go

@@ -438,13 +438,9 @@ var _ = SIGDescribe("Kubectl client", func() {
 				"BackendConfig":         true,
 				"NodeMetrics":           true,
 				"PodMetrics":            true,
-				"ScalingPolicy":         true,
 				"VolumeSnapshotClass":   true,
 				"VolumeSnapshotContent": true,
 				"VolumeSnapshot":        true,
-
-				// A CRD created by other e2e tests without any test data.
-				"Noxu": true,
 			}
 
 			apiGroups, err := c.Discovery().ServerPreferredResources()
@@ -453,6 +449,13 @@ var _ = SIGDescribe("Kubectl client", func() {
 			testableResources := etcd.GetEtcdStorageDataForNamespace(f.Namespace.Name)
 
 			for _, group := range apiGroups {
+				// This limits the scope of this test to exclude CRDs. This
+				// assumes that CRDs will not have a .k8s.io group and will have
+				// a . in their name.
+				if !strings.Contains(group.GroupVersion, ".k8s.io") && strings.Contains(group.GroupVersion, ".") {
+					continue
+				}
+
 				for _, resource := range group.APIResources {
 					if !verbsContain(resource.Verbs, "get") || ignoredResources[resource.Kind] || strings.HasPrefix(resource.Name, "e2e-test") {
 						continue