restore test behavior for CRD without validation cases

the test doesn't set empty validation but expects CRD controller to treat
nil schema specially and publish an empty schema

Author: roycaihw

test/e2e/apimachinery/crd_publish_openapi.go

@@ -341,12 +341,16 @@ func setupCRD(f *framework.Framework, schema []byte, groupSuffix string, version
 		return nil, fmt.Errorf("require at least one version for CRD")
 	}
 
-	if schema == nil {
-		schema = []byte(`type: object`)
-	}
+	expect := schema
 	props := &v1beta1.JSONSchemaProps{}
-	if err := yaml.Unmarshal(schema, props); err != nil {
-		return nil, err
+	if schema == nil {
+		// to be backwards compatible, we expect CRD controller to treat
+		// CRD with nil schema specially and publish an empty schema
+		expect = []byte(`type: object`)
+	} else {
+		if err := yaml.Unmarshal(schema, props); err != nil {
+			return nil, err
+		}
 	}
 
 	crd, err := crd.CreateMultiVersionTestCRD(f, group, func(crd *v1beta1.CustomResourceDefinition) {
@@ -360,16 +364,19 @@ func setupCRD(f *framework.Framework, schema []byte, groupSuffix string, version
 		}
 		crd.Spec.Versions = apiVersions
 
-		crd.Spec.Validation = &v1beta1.CustomResourceValidation{
-			OpenAPIV3Schema: props,
+		// set up validation when input schema isn't nil
+		if schema != nil {
+			crd.Spec.Validation = &v1beta1.CustomResourceValidation{
+				OpenAPIV3Schema: props,
+			}
 		}
 	})
 	if err != nil {
 		return nil, fmt.Errorf("failed to create CRD: %v", err)
 	}
 
 	for _, v := range crd.Crd.Spec.Versions {
-		if err := waitForDefinition(f.ClientSet, definitionName(crd, v.Name), schema); err != nil {
+		if err := waitForDefinition(f.ClientSet, definitionName(crd, v.Name), expect); err != nil {
 			return nil, fmt.Errorf("%v", err)
 		}
 	}