From 356883d0a5682bec3d7f489a6d3837533014a80e Mon Sep 17 00:00:00 2001
From: Andres Martinez Gotor <andres.martinez@grafana.com>
Date: Mon, 10 Oct 2022 16:08:33 +0200
Subject: [PATCH] Google Cloud Monitoring: Fix bucket bound for distributions
 (#56565)

(cherry picked from commit 65e56c9fb85f74ae86323e45699a1d9513d4c8f3)
---
 pkg/tsdb/cloudmonitoring/cloudmonitoring.go   |  7 +++++-
 ...series-response-distribution-explicit.json | 22 +++++++++++++++++--
 .../time_series_filter_test.go                |  4 ++--
 3 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/pkg/tsdb/cloudmonitoring/cloudmonitoring.go b/pkg/tsdb/cloudmonitoring/cloudmonitoring.go
index 65f622737d91..d6d4277f9c5b 100644
--- a/pkg/tsdb/cloudmonitoring/cloudmonitoring.go
+++ b/pkg/tsdb/cloudmonitoring/cloudmonitoring.go
@@ -596,7 +596,12 @@ func calcBucketBound(bucketOptions cloudMonitoringBucketOptions, n int) string {
 	case bucketOptions.ExponentialBuckets != nil:
 		bucketBound = strconv.FormatInt(int64(bucketOptions.ExponentialBuckets.Scale*math.Pow(bucketOptions.ExponentialBuckets.GrowthFactor, float64(n-1))), 10)
 	case bucketOptions.ExplicitBuckets != nil:
-		bucketBound = fmt.Sprintf("%g", bucketOptions.ExplicitBuckets.Bounds[n])
+		if n < len(bucketOptions.ExplicitBuckets.Bounds) {
+			bucketBound = fmt.Sprintf("%g", bucketOptions.ExplicitBuckets.Bounds[n])
+		} else {
+			lastBound := bucketOptions.ExplicitBuckets.Bounds[len(bucketOptions.ExplicitBuckets.Bounds)-1]
+			bucketBound = fmt.Sprintf("%g+", lastBound)
+		}
 	}
 	return bucketBound
 }
diff --git a/pkg/tsdb/cloudmonitoring/test-data/4-series-response-distribution-explicit.json b/pkg/tsdb/cloudmonitoring/test-data/4-series-response-distribution-explicit.json
index 98435294762b..c85be476c672 100644
--- a/pkg/tsdb/cloudmonitoring/test-data/4-series-response-distribution-explicit.json
+++ b/pkg/tsdb/cloudmonitoring/test-data/4-series-response-distribution-explicit.json
@@ -103,7 +103,16 @@
                 "4",
                 "7",
                 "12",
-                "8"
+                "8",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0"
               ]
             }
           }
@@ -198,7 +207,16 @@
                 "5",
                 "7",
                 "11",
-                "8"
+                "8",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0",
+                "0"
               ]
             }
           }
diff --git a/pkg/tsdb/cloudmonitoring/time_series_filter_test.go b/pkg/tsdb/cloudmonitoring/time_series_filter_test.go
index 4fe5fda29ad1..81b3f8775706 100644
--- a/pkg/tsdb/cloudmonitoring/time_series_filter_test.go
+++ b/pkg/tsdb/cloudmonitoring/time_series_filter_test.go
@@ -185,8 +185,8 @@ func TestTimeSeriesFilter(t *testing.T) {
 		require.NoError(t, err)
 		frames := res.Frames
 		require.NoError(t, err)
-		assert.Equal(t, 33, len(frames))
-		for i := 0; i < 33; i++ {
+		assert.Equal(t, 42, len(frames))
+		for i := 0; i < 42; i++ {
 			if i == 0 {
 				assert.Equal(t, "0", frames[i].Fields[1].Name)
 			}