From e5dfbf4adc3fea0b4d8d14a595b2733f7f668176 Mon Sep 17 00:00:00 2001
From: Tanner Altares <ta924@yahoo.com>
Date: Tue, 30 Apr 2024 12:45:10 -0500
Subject: [PATCH] Signed-off-by: Tanner Altares <ta924@yahoo.com>

block panic when prom returns range vector
---
 pkg/metrics/providers/errors.go          |  3 ++-
 pkg/metrics/providers/prometheus.go      |  6 ++++-
 pkg/metrics/providers/prometheus_test.go | 33 ++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/pkg/metrics/providers/errors.go b/pkg/metrics/providers/errors.go
index 355128399..fffc23070 100644
--- a/pkg/metrics/providers/errors.go
+++ b/pkg/metrics/providers/errors.go
@@ -19,5 +19,6 @@ package providers
 import "errors"
 
 var (
-	ErrNoValuesFound = errors.New("no values found")
+	ErrNoValuesFound          = errors.New("no values found")
+	ErrMultipleValuesReturned = errors.New("query returned multiple values")
 )
diff --git a/pkg/metrics/providers/prometheus.go b/pkg/metrics/providers/prometheus.go
index 5254de692..270012e5d 100644
--- a/pkg/metrics/providers/prometheus.go
+++ b/pkg/metrics/providers/prometheus.go
@@ -51,7 +51,8 @@ type prometheusResponse struct {
 			Metric struct {
 				Name string `json:"name"`
 			}
-			Value []interface{} `json:"value"`
+			Value  []interface{} `json:"value"`
+			Values []interface{} `json:"values"`
 		}
 	}
 }
@@ -147,6 +148,9 @@ func (p *PrometheusProvider) RunQuery(query string) (float64, error) {
 
 	var value *float64
 	for _, v := range result.Data.Result {
+		if v.Values != nil {
+			return 0, fmt.Errorf("%w", ErrMultipleValuesReturned)
+		}
 		metricValue := v.Value[1]
 		switch metricValue.(type) {
 		case string:
diff --git a/pkg/metrics/providers/prometheus_test.go b/pkg/metrics/providers/prometheus_test.go
index 484fc16df..1a4f475a0 100644
--- a/pkg/metrics/providers/prometheus_test.go
+++ b/pkg/metrics/providers/prometheus_test.go
@@ -180,6 +180,39 @@ func TestPrometheusProvider_RunQueryWithBasicAuth(t *testing.T) {
 		})
 	}
 
+	multipleResultTests := []struct {
+		name        string
+		queryResult string
+	}{
+		{name: "values instead of value", queryResult: `{"status": "success","data": {"resultType": "matrix","result": [{"metric": {"__name__": "processTime_seconds:avg"},"values": [[1714404069.294,"NaN"],[1714404071.3,"NaN"],[1714404099.294,"NaN"],[1714404101.3,"NaN"]]},{"metric": {"__name__": "processTime_seconds:avg"},"values": [[1714404069.294,"NaN"],[1714404071.3,"NaN"],[1714404099.294,"NaN"],[1714404101.3,"NaN"]]}]}}`},
+	}
+
+	for _, tt := range multipleResultTests {
+		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()
+
+			clients := prometheusFake()
+
+			template, err := clients.flaggerClient.FlaggerV1beta1().
+				MetricTemplates("default").Get(context.TODO(), "prometheus", metav1.GetOptions{})
+			require.NoError(t, err)
+			template.Spec.Provider.Address = ts.URL
+
+			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, ErrMultipleValuesReturned))
+		})
+	}
+
 }
 
 func TestPrometheusProvider_RunQueryWithBearerAuth(t *testing.T) {