From 98153fcedc27b69d99c43ddafc3ca98a405898ea Mon Sep 17 00:00:00 2001
From: Jay Vyas <jay@apache.org>
Date: Wed, 2 Dec 2015 17:51:34 -0500
Subject: [PATCH] HPA: parameterize stasis, minReplicas, maxReplicas as struct.

---
 test/e2e/horizontal_pod_autoscaling.go | 82 +++++++++++++++++++-------
 1 file changed, 61 insertions(+), 21 deletions(-)

diff --git a/test/e2e/horizontal_pod_autoscaling.go b/test/e2e/horizontal_pod_autoscaling.go
index 3205ae6b843..b55e593a063 100644
--- a/test/e2e/horizontal_pod_autoscaling.go
+++ b/test/e2e/horizontal_pod_autoscaling.go
@@ -26,10 +26,9 @@ import (
 )
 
 const (
-	kindRC           = "replicationController"
-	kindDeployment   = "deployment"
-	subresource      = "scale"
-	stabilityTimeout = 10 * time.Minute
+	kindRC         = "replicationController"
+	kindDeployment = "deployment"
+	subresource    = "scale"
 )
 
 var _ = Describe("Horizontal pod autoscaling (scale resource: CPU) [Skipped]", func() {
@@ -60,28 +59,69 @@ var _ = Describe("Horizontal pod autoscaling (scale resource: CPU) [Skipped]", f
 	})
 })
 
-func scaleUp(name, kind string, rc *ResourceConsumer, f *Framework) {
-	rc = NewDynamicResourceConsumer(name, kind, 1, 250, 0, 500, 100, f)
+// HPAScaleTest struct is used by the scale(...) function.
+type HPAScaleTest struct {
+	initPods          int
+	cpuStart          int
+	maxCPU            int64
+	idealCPU          int
+	minPods           int
+	maxPods           int
+	firstScale        int
+	firstScaleStasis  time.Duration
+	cpuBurst          int
+	secondScale       int
+	secondScaleStasis time.Duration
+}
+
+// run is a method which runs an HPA lifecycle, from a starting state, to an expected
+// The initial state is defined by the initPods parameter.
+// The first state change is due to the CPU being consumed initially, which HPA responds to by changing pod counts.
+// The second state change is due to the CPU burst parameter, which HPA again responds to.
+// TODO The use of 3 states is arbitrary, we could eventually make this test handle "n" states once this test stabilizes.
+func (scaleTest *HPAScaleTest) run(name, kind string, rc *ResourceConsumer, f *Framework) {
+	rc = NewDynamicResourceConsumer(name, kind, scaleTest.initPods, scaleTest.cpuStart, 0, scaleTest.maxCPU, 100, f)
 	defer rc.CleanUp()
-	createCPUHorizontalPodAutoscaler(rc, 20)
-	rc.WaitForReplicas(3)
-	rc.EnsureDesiredReplicas(3, stabilityTimeout)
-	rc.ConsumeCPU(700)
-	rc.WaitForReplicas(5)
+	createCPUHorizontalPodAutoscaler(rc, scaleTest.idealCPU, scaleTest.minPods, scaleTest.maxPods)
+	rc.WaitForReplicas(scaleTest.firstScale)
+	rc.EnsureDesiredReplicas(scaleTest.firstScale, scaleTest.firstScaleStasis)
+	rc.ConsumeCPU(scaleTest.cpuBurst)
+	rc.WaitForReplicas(scaleTest.secondScale)
+}
+
+func scaleUp(name, kind string, rc *ResourceConsumer, f *Framework) {
+	scaleTest := &HPAScaleTest{
+		initPods:         1,
+		cpuStart:         250,
+		maxCPU:           500,
+		idealCPU:         .2 * 100,
+		minPods:          1,
+		maxPods:          5,
+		firstScale:       3,
+		firstScaleStasis: 10 * time.Minute,
+		cpuBurst:         700,
+		secondScale:      5,
+	}
+	scaleTest.run(name, kind, rc, f)
 }
 
 func scaleDown(name, kind string, rc *ResourceConsumer, f *Framework) {
-	rc = NewDynamicResourceConsumer(name, kind, 5, 400, 0, 500, 100, f)
-	defer rc.CleanUp()
-	createCPUHorizontalPodAutoscaler(rc, 30)
-	rc.WaitForReplicas(3)
-	rc.EnsureDesiredReplicas(3, stabilityTimeout)
-	rc.ConsumeCPU(100)
-	rc.WaitForReplicas(1)
+	scaleTest := &HPAScaleTest{
+		initPods:         5,
+		cpuStart:         400,
+		maxCPU:           500,
+		idealCPU:         .3 * 100,
+		minPods:          1,
+		maxPods:          5,
+		firstScale:       3,
+		firstScaleStasis: 10 * time.Minute,
+		cpuBurst:         100,
+		secondScale:      1,
+	}
+	scaleTest.run(name, kind, rc, f)
 }
 
-func createCPUHorizontalPodAutoscaler(rc *ResourceConsumer, cpu int) {
-	minReplicas := 1
+func createCPUHorizontalPodAutoscaler(rc *ResourceConsumer, cpu, minReplicas, maxRepl int) {
 	hpa := &extensions.HorizontalPodAutoscaler{
 		ObjectMeta: api.ObjectMeta{
 			Name:      rc.name,
@@ -94,7 +134,7 @@ func createCPUHorizontalPodAutoscaler(rc *ResourceConsumer, cpu int) {
 				Subresource: subresource,
 			},
 			MinReplicas:    &minReplicas,
-			MaxReplicas:    5,
+			MaxReplicas:    maxRepl,
 			CPUUtilization: &extensions.CPUTargetUtilization{TargetPercentage: cpu},
 		},
 	}