From af3594dfa5211dae5f413cfdf46c78dfc2dabdc4 Mon Sep 17 00:00:00 2001
From: Adam Malcontenti-Wilson <amalcontenti-wilson@zendesk.com>
Date: Wed, 11 May 2022 16:38:51 +1000
Subject: [PATCH] disruptioncontroller: check for scale subresource correctly

---
 pkg/controller/disruption/disruption.go      | 20 ++++++++++++-------
 pkg/controller/disruption/disruption_test.go | 21 +++++++++++++++++++-
 2 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/pkg/controller/disruption/disruption.go b/pkg/controller/disruption/disruption.go
index 3c8fcbab770..346a3224149 100644
--- a/pkg/controller/disruption/disruption.go
+++ b/pkg/controller/disruption/disruption.go
@@ -297,14 +297,13 @@ func (dc *DisruptionController) getScaleController(ctx context.Context, controll
 		return nil, err
 	}
 	gr := mapping.Resource.GroupResource()
-
 	scale, err := dc.scaleNamespacer.Scales(namespace).Get(ctx, gr, controllerRef.Name, metav1.GetOptions{})
 	if err != nil {
 		if errors.IsNotFound(err) {
 			// The IsNotFound error can mean either that the resource does not exist,
 			// or it exist but doesn't implement the scale subresource. We check which
 			// situation we are facing so we can give an appropriate error message.
-			isScale, err := dc.implementsScale(gv, controllerRef.Kind)
+			isScale, err := dc.implementsScale(mapping.Resource)
 			if err != nil {
 				return nil, err
 			}
@@ -321,17 +320,24 @@ func (dc *DisruptionController) getScaleController(ctx context.Context, controll
 	return &controllerAndScale{scale.UID, scale.Spec.Replicas}, nil
 }
 
-func (dc *DisruptionController) implementsScale(gv schema.GroupVersion, kind string) (bool, error) {
-	resourceList, err := dc.discoveryClient.ServerResourcesForGroupVersion(gv.String())
+func (dc *DisruptionController) implementsScale(gvr schema.GroupVersionResource) (bool, error) {
+	resourceList, err := dc.discoveryClient.ServerResourcesForGroupVersion(gvr.GroupVersion().String())
 	if err != nil {
 		return false, err
 	}
+
+	scaleSubresourceName := fmt.Sprintf("%s/scale", gvr.Resource)
 	for _, resource := range resourceList.APIResources {
-		if resource.Kind != kind {
+		if resource.Name != scaleSubresourceName {
 			continue
 		}
-		if strings.HasSuffix(resource.Name, "/scale") {
-			return true, nil
+
+		for _, scaleGv := range scaleclient.NewScaleConverter().ScaleVersions() {
+			if resource.Group == scaleGv.Group &&
+				resource.Version == scaleGv.Version &&
+				resource.Kind == "Scale" {
+				return true, nil
+			}
 		}
 	}
 	return false, nil
diff --git a/pkg/controller/disruption/disruption_test.go b/pkg/controller/disruption/disruption_test.go
index b242b35d761..0a4220f6c93 100644
--- a/pkg/controller/disruption/disruption_test.go
+++ b/pkg/controller/disruption/disruption_test.go
@@ -663,6 +663,25 @@ func TestScaleFinderNoResource(t *testing.T) {
 		expectError  bool
 	}{
 		"resource implements scale": {
+			apiResources: []metav1.APIResource{
+				{
+					Kind: customGVK.Kind,
+					Name: resourceName + "/status",
+				},
+				{
+					Kind:    "Scale",
+					Group:   autoscalingapi.GroupName,
+					Version: "v1",
+					Name:    resourceName + "/scale",
+				},
+				{
+					Kind: customGVK.Kind,
+					Name: resourceName,
+				},
+			},
+			expectError: false,
+		},
+		"resource implements unsupported data format for scale subresource": {
 			apiResources: []metav1.APIResource{
 				{
 					Kind: customGVK.Kind,
@@ -673,7 +692,7 @@ func TestScaleFinderNoResource(t *testing.T) {
 					Name: resourceName + "/scale",
 				},
 			},
-			expectError: false,
+			expectError: true,
 		},
 		"resource does not implement scale": {
 			apiResources: []metav1.APIResource{