From eb55e2b980dafdb81608bdc0f851f8639e12a3af Mon Sep 17 00:00:00 2001
From: Richa Banker <richabanker@google.com>
Date: Mon, 9 Jan 2023 17:33:44 -0800
Subject: [PATCH] Add e2e test for checking /metrics/slis endpoint for API
 server

---
 .../framework/metrics/api_server_metrics.go    |  8 ++++++++
 test/e2e/framework/metrics/metrics_grabber.go  | 18 ++++++++++++++++++
 .../monitoring/metrics_grabber.go              | 10 ++++++++++
 3 files changed, 36 insertions(+)

diff --git a/test/e2e/framework/metrics/api_server_metrics.go b/test/e2e/framework/metrics/api_server_metrics.go
index c22c5c45a00..5d9e1bb5743 100644
--- a/test/e2e/framework/metrics/api_server_metrics.go
+++ b/test/e2e/framework/metrics/api_server_metrics.go
@@ -50,3 +50,11 @@ func (g *Grabber) getMetricsFromAPIServer(ctx context.Context) (string, error) {
 	}
 	return string(rawOutput), nil
 }
+
+func (g *Grabber) getMetricsSLIsFromAPIServer(ctx context.Context) (string, error) {
+	rawOutput, err := g.client.CoreV1().RESTClient().Get().RequestURI("/metrics/slis").Do(ctx).Raw()
+	if err != nil {
+		return "", err
+	}
+	return string(rawOutput), nil
+}
diff --git a/test/e2e/framework/metrics/metrics_grabber.go b/test/e2e/framework/metrics/metrics_grabber.go
index f7c34d8ec77..87e1bbaec8d 100644
--- a/test/e2e/framework/metrics/metrics_grabber.go
+++ b/test/e2e/framework/metrics/metrics_grabber.go
@@ -54,6 +54,7 @@ var MetricsGrabbingDisabledError = errors.New("metrics grabbing disabled")
 // Collection is metrics collection of components
 type Collection struct {
 	APIServerMetrics          APIServerMetrics
+	APIServerMetricsSLIs      APIServerMetrics
 	ControllerManagerMetrics  ControllerManagerMetrics
 	SnapshotControllerMetrics SnapshotControllerMetrics
 	KubeletMetrics            map[string]KubeletMetrics
@@ -323,6 +324,15 @@ func (g *Grabber) GrabFromAPIServer(ctx context.Context) (APIServerMetrics, erro
 	return parseAPIServerMetrics(output)
 }
 
+// GrabMetricsSLIsFromAPIServer returns metrics from API server
+func (g *Grabber) GrabMetricsSLIsFromAPIServer(ctx context.Context) (APIServerMetrics, error) {
+	output, err := g.getMetricsSLIsFromAPIServer(ctx)
+	if err != nil {
+		return APIServerMetrics{}, err
+	}
+	return parseAPIServerMetrics(output)
+}
+
 // Grab returns metrics from corresponding component
 func (g *Grabber) Grab(ctx context.Context) (Collection, error) {
 	result := Collection{}
@@ -383,6 +393,14 @@ func (g *Grabber) Grab(ctx context.Context) (Collection, error) {
 			}
 		}
 	}
+	if g.grabFromAPIServer {
+		metrics, err := g.GrabMetricsSLIsFromAPIServer(ctx)
+		if err != nil {
+			errs = append(errs, err)
+		} else {
+			result.APIServerMetricsSLIs = metrics
+		}
+	}
 	if len(errs) > 0 {
 		return result, fmt.Errorf("Errors while grabbing metrics: %v", errs)
 	}
diff --git a/test/e2e/instrumentation/monitoring/metrics_grabber.go b/test/e2e/instrumentation/monitoring/metrics_grabber.go
index 4d2df772a05..e7e7c4f7a72 100644
--- a/test/e2e/instrumentation/monitoring/metrics_grabber.go
+++ b/test/e2e/instrumentation/monitoring/metrics_grabber.go
@@ -93,4 +93,14 @@ var _ = instrumentation.SIGDescribe("MetricsGrabber", func() {
 		framework.ExpectNoError(err)
 		gomega.Expect(response).NotTo(gomega.BeEmpty())
 	})
+
+	ginkgo.It("should grab all metrics slis from API server.", func(ctx context.Context) {
+		ginkgo.By("Connecting to /metrics/slis endpoint")
+		response, err := grabber.GrabMetricsSLIsFromAPIServer(ctx)
+		if errors.Is(err, e2emetrics.MetricsGrabbingDisabledError) {
+			e2eskipper.Skipf("%v", err)
+		}
+		framework.ExpectNoError(err)
+		gomega.Expect(response).NotTo(gomega.BeEmpty())
+	})
 })