From cd3a1d8478ce61b236d3811a956cdefb81a06a8e Mon Sep 17 00:00:00 2001
From: ashokhein <ashokhein@gmail.com>
Date: Mon, 24 Jan 2022 12:58:57 +0000
Subject: [PATCH] fixed bug when Prometheus returns NaN

Signed-off-by: ashokhein <ashokhein@gmail.com>
---
 pkg/metrics/providers/prometheus.go      |  3 +-
 pkg/metrics/providers/prometheus_test.go | 47 +++++++++++++++---------
 2 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/pkg/metrics/providers/prometheus.go b/pkg/metrics/providers/prometheus.go
index e0660369..bead94a8 100644
--- a/pkg/metrics/providers/prometheus.go
+++ b/pkg/metrics/providers/prometheus.go
@@ -22,6 +22,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"math"
 	"net/http"
 	"net/url"
 	"path"
@@ -148,7 +149,7 @@ func (p *PrometheusProvider) RunQuery(query string) (float64, error) {
 			value = &f
 		}
 	}
-	if value == nil {
+	if value == nil || math.IsNaN(*value) {
 		return 0, fmt.Errorf("%w", ErrNoValuesFound)
 	}
 
diff --git a/pkg/metrics/providers/prometheus_test.go b/pkg/metrics/providers/prometheus_test.go
index a0ad1a65..84ee62c0 100644
--- a/pkg/metrics/providers/prometheus_test.go
+++ b/pkg/metrics/providers/prometheus_test.go
@@ -134,29 +134,40 @@ func TestPrometheusProvider_RunQueryWithBasicAuth(t *testing.T) {
 		assert.Equal(t, float64(100), val)
 	})
 
-	t.Run("no values", func(t *testing.T) {
-		ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			json := `{"status":"success","data":{"resultType":"vector","result":[]}}`
-			w.Write([]byte(json))
-		}))
-		defer ts.Close()
+	noResultTests := []struct {
+		name        string
+		queryResult string
+	}{
+		{name: "no values result", queryResult: `{"status":"success","data":{"resultType":"vector","result":[]}}`},
+		{name: "NaN result", queryResult: `{"status":"success","data":{"resultType":"vector","result":[{"metric":{},"value":[1643023250.379,"NaN"]}]}}`},
+	}
 
-		clients := prometheusFake()
+	for _, tt := range noResultTests {
+		t.Run(tt.name, func(t *testing.T) {
+			ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				json := tt.queryResult
+				w.Write([]byte(json))
+			}))
+			defer ts.Close()
 
-		template, err := clients.flaggerClient.FlaggerV1beta1().
-			MetricTemplates("default").Get(context.TODO(), "prometheus", metav1.GetOptions{})
-		require.NoError(t, err)
-		template.Spec.Provider.Address = ts.URL
+			clients := prometheusFake()
 
-		secret, err := clients.kubeClient.CoreV1().Secrets("default").Get(context.TODO(), "prometheus", metav1.GetOptions{})
-		require.NoError(t, err)
+			template, err := clients.flaggerClient.FlaggerV1beta1().
+				MetricTemplates("default").Get(context.TODO(), "prometheus", metav1.GetOptions{})
+			require.NoError(t, err)
+			template.Spec.Provider.Address = ts.URL
 
-		prom, err := NewPrometheusProvider(template.Spec.Provider, secret.Data)
-		require.NoError(t, err)
+			secret, err := clients.kubeClient.CoreV1().Secrets("default").Get(context.TODO(), "prometheus", metav1.GetOptions{})
+			require.NoError(t, err)
+
+			prom, err := NewPrometheusProvider(template.Spec.Provider, secret.Data)
+			require.NoError(t, err)
+
+			_, err = prom.RunQuery(template.Spec.Query)
+			require.True(t, errors.Is(err, ErrNoValuesFound))
+		})
+	}
 
-		_, err = prom.RunQuery(template.Spec.Query)
-		require.True(t, errors.Is(err, ErrNoValuesFound))
-	})
 }
 
 func TestPrometheusProvider_IsOnline(t *testing.T) {