From b87d06eb69bca9ee02f211a851184539e3fef5ca Mon Sep 17 00:00:00 2001
From: Sebastian Spaink <3441183+sspaink@users.noreply.github.com>
Date: Wed, 27 Jul 2022 10:31:42 -0500
Subject: [PATCH] fix(inputs.stackdriver): Handle when no buckets available
 (#11556)

---
 plugins/inputs/stackdriver/stackdriver.go     | 93 +++++++++++++++----
 .../inputs/stackdriver/stackdriver_test.go    | 73 +++++++++++++++
 2 files changed, 146 insertions(+), 20 deletions(-)

diff --git a/plugins/inputs/stackdriver/stackdriver.go b/plugins/inputs/stackdriver/stackdriver.go
index cd45f2f62..25cf4c430 100644
--- a/plugins/inputs/stackdriver/stackdriver.go
+++ b/plugins/inputs/stackdriver/stackdriver.go
@@ -4,6 +4,7 @@ package stackdriver
 import (
 	"context"
 	_ "embed"
+	"errors"
 	"fmt"
 	"math"
 	"strconv"
@@ -564,6 +565,73 @@ func (s *Stackdriver) gatherTimeSeries(
 	return nil
 }
 
+type Buckets interface {
+	Amount() int32
+	UpperBound(i int32) float64
+}
+
+type LinearBuckets struct {
+	*distributionpb.Distribution_BucketOptions_Linear
+}
+
+func (l *LinearBuckets) Amount() int32 {
+	return l.NumFiniteBuckets + 2
+}
+
+func (l *LinearBuckets) UpperBound(i int32) float64 {
+	return l.Offset + (l.Width * float64(i))
+}
+
+type ExponentialBuckets struct {
+	*distributionpb.Distribution_BucketOptions_Exponential
+}
+
+func (e *ExponentialBuckets) Amount() int32 {
+	return e.NumFiniteBuckets + 2
+}
+
+func (e *ExponentialBuckets) UpperBound(i int32) float64 {
+	width := math.Pow(e.GrowthFactor, float64(i))
+	return e.Scale * width
+}
+
+type ExplicitBuckets struct {
+	*distributionpb.Distribution_BucketOptions_Explicit
+}
+
+func (e *ExplicitBuckets) Amount() int32 {
+	return int32(len(e.Bounds)) + 1
+}
+
+func (e *ExplicitBuckets) UpperBound(i int32) float64 {
+	return e.Bounds[i]
+}
+
+func NewBucket(dist *distributionpb.Distribution) (Buckets, error) {
+	linearBuckets := dist.BucketOptions.GetLinearBuckets()
+	if linearBuckets != nil {
+		var l LinearBuckets
+		l.Distribution_BucketOptions_Linear = linearBuckets
+		return &l, nil
+	}
+
+	exponentialBuckets := dist.BucketOptions.GetExponentialBuckets()
+	if exponentialBuckets != nil {
+		var e ExponentialBuckets
+		e.Distribution_BucketOptions_Exponential = exponentialBuckets
+		return &e, nil
+	}
+
+	explicitBuckets := dist.BucketOptions.GetExplicitBuckets()
+	if explicitBuckets != nil {
+		var e ExplicitBuckets
+		e.Distribution_BucketOptions_Explicit = explicitBuckets
+		return &e, nil
+	}
+
+	return nil, errors.New("no buckets available")
+}
+
 // AddDistribution adds metrics from a distribution value type.
 func (s *Stackdriver) addDistribution(dist *distributionpb.Distribution, tags map[string]string, ts time.Time,
 	grouper *lockedSeriesGrouper, tsConf *timeSeriesConf,
@@ -590,18 +658,11 @@ func (s *Stackdriver) addDistribution(dist *distributionpb.Distribution, tags ma
 		}
 	}
 
-	linearBuckets := dist.BucketOptions.GetLinearBuckets()
-	exponentialBuckets := dist.BucketOptions.GetExponentialBuckets()
-	explicitBuckets := dist.BucketOptions.GetExplicitBuckets()
-
-	var numBuckets int32
-	if linearBuckets != nil {
-		numBuckets = linearBuckets.NumFiniteBuckets + 2
-	} else if exponentialBuckets != nil {
-		numBuckets = exponentialBuckets.NumFiniteBuckets + 2
-	} else {
-		numBuckets = int32(len(explicitBuckets.Bounds)) + 1
+	bucket, err := NewBucket(dist)
+	if err != nil {
+		return err
 	}
+	numBuckets := bucket.Amount()
 
 	var i int32
 	var count int64
@@ -611,15 +672,7 @@ func (s *Stackdriver) addDistribution(dist *distributionpb.Distribution, tags ma
 		if i == numBuckets-1 {
 			tags["lt"] = "+Inf"
 		} else {
-			var upperBound float64
-			if linearBuckets != nil {
-				upperBound = linearBuckets.Offset + (linearBuckets.Width * float64(i))
-			} else if exponentialBuckets != nil {
-				width := math.Pow(exponentialBuckets.GrowthFactor, float64(i))
-				upperBound = exponentialBuckets.Scale * width
-			} else if explicitBuckets != nil {
-				upperBound = explicitBuckets.Bounds[i]
-			}
+			upperBound := bucket.UpperBound(i)
 			tags["lt"] = strconv.FormatFloat(upperBound, 'f', -1, 64)
 		}
 
diff --git a/plugins/inputs/stackdriver/stackdriver_test.go b/plugins/inputs/stackdriver/stackdriver_test.go
index ad6b15145..b3f926072 100644
--- a/plugins/inputs/stackdriver/stackdriver_test.go
+++ b/plugins/inputs/stackdriver/stackdriver_test.go
@@ -95,7 +95,78 @@ func TestGather(t *testing.T) {
 		descriptor *metricpb.MetricDescriptor
 		timeseries *monitoringpb.TimeSeries
 		expected   []telegraf.Metric
+		wantAccErr bool
 	}{
+		{
+			name: "no_bucket",
+			descriptor: &metricpb.MetricDescriptor{
+				ValueType: metricpb.MetricDescriptor_DISTRIBUTION,
+			},
+			timeseries: createTimeSeries(
+				&monitoringpb.Point{
+					Interval: &monitoringpb.TimeInterval{
+						EndTime: &timestamppb.Timestamp{
+							Seconds: now.Unix(),
+						},
+					},
+					Value: &monitoringpb.TypedValue{
+						Value: &monitoringpb.TypedValue_DistributionValue{
+							DistributionValue: &distribution.Distribution{
+								Count: 2,
+							},
+						},
+					},
+				},
+				metricpb.MetricDescriptor_DISTRIBUTION,
+			),
+			expected: []telegraf.Metric{
+				testutil.MustMetric("",
+					map[string]string{
+						"project_id":    "test",
+						"resource_type": "global",
+					},
+					map[string]interface{}{
+						"value_count":                    2,
+						"value_mean":                     float64(0),
+						"value_sum_of_squared_deviation": float64(0),
+					},
+					now),
+			},
+			wantAccErr: true,
+		},
+		{
+			name: "int64",
+			descriptor: &metricpb.MetricDescriptor{
+				Type:      "telegraf/cpu/usage",
+				ValueType: metricpb.MetricDescriptor_INT64,
+			},
+			timeseries: createTimeSeries(
+				&monitoringpb.Point{
+					Interval: &monitoringpb.TimeInterval{
+						EndTime: &timestamppb.Timestamp{
+							Seconds: now.Unix(),
+						},
+					},
+					Value: &monitoringpb.TypedValue{
+						Value: &monitoringpb.TypedValue_Int64Value{
+							Int64Value: 42,
+						},
+					},
+				},
+				metricpb.MetricDescriptor_INT64,
+			),
+			expected: []telegraf.Metric{
+				testutil.MustMetric("telegraf/cpu",
+					map[string]string{
+						"resource_type": "global",
+						"project_id":    "test",
+					},
+					map[string]interface{}{
+						"usage": 42,
+					},
+					now),
+			},
+		},
 		{
 			name: "double",
 			descriptor: &metricpb.MetricDescriptor{
@@ -673,6 +744,8 @@ func TestGather(t *testing.T) {
 
 			err := s.Gather(&acc)
 			require.NoError(t, err)
+			require.Equalf(t, len(acc.Errors) > 0, tt.wantAccErr,
+				"Accumulator errors. got=%v, want=%t", acc.Errors, tt.wantAccErr)
 
 			actual := []telegraf.Metric{}
 			for _, m := range acc.Metrics {