From c721d8cf65132b45d0a75da56034c317c26a119f Mon Sep 17 00:00:00 2001
From: Riaan Kleinhans <riaan@ii.coop>
Date: Wed, 3 Feb 2021 10:34:28 +1300
Subject: [PATCH] Create ReplicaSetScale test

---
 test/e2e/apps/replica_set.go | 72 ++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/test/e2e/apps/replica_set.go b/test/e2e/apps/replica_set.go
index f08df5653f0..7edc94caa9d 100644
--- a/test/e2e/apps/replica_set.go
+++ b/test/e2e/apps/replica_set.go
@@ -18,10 +18,14 @@ package apps
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"time"
 
 	appsv1 "k8s.io/api/apps/v1"
+	autoscalingv1 "k8s.io/api/autoscaling/v1"
+	"k8s.io/apimachinery/pkg/types"
+
 	v1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
@@ -114,6 +118,10 @@ var _ = SIGDescribe("ReplicaSet", func() {
 	framework.ConformanceIt("should adopt matching pods on creation and release no longer matching pods", func() {
 		testRSAdoptMatchingAndReleaseNotMatching(f)
 	})
+
+	ginkgo.It("Replicaset should have a working scale subresource", func() {
+		testRSScaleSubresources(f)
+	})
 })
 
 // A basic test to check the deployment of an image using a ReplicaSet. The
@@ -340,3 +348,67 @@ func testRSAdoptMatchingAndReleaseNotMatching(f *framework.Framework) {
 	})
 	framework.ExpectNoError(err)
 }
+
+func testRSScaleSubresources(f *framework.Framework) {
+	ns := f.Namespace.Name
+	c := f.ClientSet
+
+	// Create webserver pods.
+	rsPodLabels := map[string]string{
+		"name": "sample-pod",
+		"pod":  WebserverImageName,
+	}
+
+	rsName := "test-rs"
+	replicas := int32(1)
+	ginkgo.By(fmt.Sprintf("Creating replica set %q that asks for more than the allowed pod quota", rsName))
+	rs := newRS(rsName, replicas, rsPodLabels, WebserverImageName, WebserverImage, nil)
+	_, err := c.AppsV1().ReplicaSets(ns).Create(context.TODO(), rs, metav1.CreateOptions{})
+	framework.ExpectNoError(err)
+
+	// Verify that the required pods have come up.
+	err = e2epod.VerifyPodsRunning(c, ns, "sample-pod", false, replicas)
+	framework.ExpectNoError(err, "error in waiting for pods to come up: %s", err)
+
+	ginkgo.By("getting scale subresource")
+	scale, err := c.AppsV1().ReplicaSets(ns).GetScale(context.TODO(), rsName, metav1.GetOptions{})
+	if err != nil {
+		framework.Failf("Failed to get scale subresource: %v", err)
+	}
+	framework.ExpectEqual(scale.Spec.Replicas, int32(1))
+	framework.ExpectEqual(scale.Status.Replicas, int32(1))
+
+	ginkgo.By("updating a scale subresource")
+	scale.ResourceVersion = "" // indicate the scale update should be unconditional
+	scale.Spec.Replicas = 2
+	scaleResult, err := c.AppsV1().ReplicaSets(ns).UpdateScale(context.TODO(), rsName, scale, metav1.UpdateOptions{})
+	if err != nil {
+		framework.Failf("Failed to put scale subresource: %v", err)
+	}
+	framework.ExpectEqual(scaleResult.Spec.Replicas, int32(2))
+
+	ginkgo.By("verifying the replicaset Spec.Replicas was modified")
+	rs, err = c.AppsV1().ReplicaSets(ns).Get(context.TODO(), rsName, metav1.GetOptions{})
+	if err != nil {
+		framework.Failf("Failed to get statefulset resource: %v", err)
+	}
+	framework.ExpectEqual(*(rs.Spec.Replicas), int32(2))
+
+	ginkgo.By("Patch a scale subresource")
+	scale.ResourceVersion = "" // indicate the scale update should be unconditional
+	scale.Spec.Replicas = 4    // should be 2 after "UpdateScale" operation, now Patch to 4
+	rsScalePatchPayload, err := json.Marshal(autoscalingv1.Scale{
+		Spec: autoscalingv1.ScaleSpec{
+			Replicas: scale.Spec.Replicas,
+		},
+	})
+	framework.ExpectNoError(err, "Could not Marshal JSON for patch payload")
+
+	_, err = c.AppsV1().ReplicaSets(ns).Patch(context.TODO(), rsName, types.StrategicMergePatchType, []byte(rsScalePatchPayload), metav1.PatchOptions{}, "scale")
+	framework.ExpectNoError(err, "Failed to patch replicaset: %v", err)
+
+	rs, err = c.AppsV1().ReplicaSets(ns).Get(context.TODO(), rsName, metav1.GetOptions{})
+	framework.ExpectNoError(err, "Failed to get replicaset resource: %v", err)
+	framework.ExpectEqual(*(rs.Spec.Replicas), int32(4), "replicaset should have 4 replicas")
+
+}