From d0a2da5d17a98779d8ef5e7a910fc210fd550e9d Mon Sep 17 00:00:00 2001
From: spyridon chortis <86228064+spchortis@users.noreply.github.com>
Date: Thu, 26 Oct 2023 15:45:13 +0100
Subject: [PATCH] ci: once the demo app is deployed can it scale up and down
 when under load? (#192)

Co-authored-by: Pedro Silva <pedro.silva@wisenet.inf.br>
---
 examples/sample-app/sample-app.yaml    |  7 +++
 examples/sample-app/sample_app_test.go | 69 +++++++++++++++++++++-----
 2 files changed, 64 insertions(+), 12 deletions(-)

diff --git a/examples/sample-app/sample-app.yaml b/examples/sample-app/sample-app.yaml
index e3ed9f821..40d7f5da1 100644
--- a/examples/sample-app/sample-app.yaml
+++ b/examples/sample-app/sample-app.yaml
@@ -4,6 +4,13 @@ metadata:
   name: sample-app
 spec:
   template:
+    metadata:
+      annotations:
+        # For testing purposes set request-per-second to 1 to force scaling
+        autoscaling.knative.dev/target: "1"
+        autoscaling.knative.dev/metric: "rps"
+      labels:
+        service: "ksample"
     spec:
       containers:
         - image: nginx:stable
diff --git a/examples/sample-app/sample_app_test.go b/examples/sample-app/sample_app_test.go
index 4293601cc..4943fbed0 100644
--- a/examples/sample-app/sample_app_test.go
+++ b/examples/sample-app/sample_app_test.go
@@ -3,10 +3,12 @@ package test
 import (
 	"fmt"
 	"os"
+	"strings"
 	"testing"
 	"time"
 
-	_ "github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/assert"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/gruntwork-io/terratest/modules/k8s"
 
@@ -30,17 +32,60 @@ func TestExampleApp(t *testing.T) {
 	k8s.KubectlApply(t, kubectlOptions, "sample-app.yaml")
 
 	// =============================================================
-	http_helper.HTTPDoWithRetry(
-		t,
-		"GET",
-		fmt.Sprintf("http://%s", os.Getenv("INITIUM_LB_ENDPOINT")),
-		[]byte("Hello world from initium-platform!"),
-		map[string]string{"Host": "sample-app.default.example.com"},
-		200,
-		30,
-		3*time.Second,
-		nil,
-	)
+
+	numRequests := 5
+
+	for i := 0; i < numRequests; i++ {
+
+		http_helper.HTTPDoWithRetry(
+			t,
+			"GET",
+			fmt.Sprintf("http://%s", os.Getenv("INITIUM_LB_ENDPOINT")),
+			[]byte("Hello world from initium-platform!"),
+			map[string]string{"Host": "sample-app.default.example.com"},
+			200,
+			30,
+			3*time.Second,
+			nil,
+		)
+	}
+
+	sampleAppLabel := "ksample"
+	prefix := "sample-app"
+
+	//Wait for the pods to be created
+	time.Sleep(5 * time.Second)
+
+	podOptions := metav1.ListOptions{
+		LabelSelector: fmt.Sprintf("service=%s", sampleAppLabel),
+	}
+
+	pods := k8s.ListPods(t, kubectlOptions, podOptions)
+
+	assert.NotNil(t, pods)
+	// Validate knative scale-out process was effective
+	assert.Greater(t, len(pods), 1)
+
+	// Wait for knative to scale-in
+	time.Sleep(70 * time.Second)
+
+	replicaSets, err := k8s.RunKubectlAndGetOutputE(t, kubectlOptions, "get", "rs")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	replicaSetNames := strings.Fields(replicaSets)
+
+	var replicaSet string
+	for _, rs := range replicaSetNames {
+		if strings.HasPrefix(rs, prefix) {
+			replicaSet = rs
+		}
+	}
+
+	rs := k8s.GetReplicaSet(t, kubectlOptions, replicaSet)
+	// Validate knative scale-in process was effective
+	assert.Equal(t, int(rs.Status.Replicas), 0)
 
 	// =============================================================
 	k8s.KubectlDelete(t, kubectlOptions, "sample-app.yaml")