stackdriver: fix for float64 bounds for distribution metrics

Adds support for explicit distribution metrics and float64 bounds

Fixes #14509

pkg/tsdb/stackdriver/stackdriver.go

@@ -336,6 +336,8 @@ func (e *StackdriverExecutor) unmarshalResponse(res *http.Response) (Stackdriver
 		return StackdriverResponse{}, err
 	}
 
+	// slog.Info("stackdriver", "response", string(body))
+
 	if res.StatusCode/100 != 2 {
 		slog.Error("Request failed", "status", res.Status, "body", string(body))
 		return StackdriverResponse{}, fmt.Errorf(string(body))
@@ -559,7 +561,7 @@ func calcBucketBound(bucketOptions StackdriverBucketOptions, n int) string {
 	} else if bucketOptions.ExponentialBuckets != nil {
 		bucketBound = strconv.FormatInt(int64(bucketOptions.ExponentialBuckets.Scale*math.Pow(bucketOptions.ExponentialBuckets.GrowthFactor, float64(n-1))), 10)
 	} else if bucketOptions.ExplicitBuckets != nil {
-		bucketBound = strconv.FormatInt(bucketOptions.ExplicitBuckets.Bounds[(n-1)], 10)
+		bucketBound = fmt.Sprintf("%g", bucketOptions.ExplicitBuckets.Bounds[n])
 	}
 	return bucketBound
 }

pkg/tsdb/stackdriver/stackdriver_test.go

@@ -344,8 +344,8 @@ func TestStackdriver(t *testing.T) {
 				})
 			})
 
-			Convey("when data from query is distribution", func() {
-				data, err := loadTestFile("./test-data/3-series-response-distribution.json")
+			Convey("when data from query is distribution with exponential bounds", func() {
+				data, err := loadTestFile("./test-data/3-series-response-distribution-exponential.json")
 				So(err, ShouldBeNil)
 				So(len(data.TimeSeries), ShouldEqual, 1)
 
@@ -370,6 +370,14 @@ func TestStackdriver(t *testing.T) {
 					So(res.Series[0].Points[2][1].Float64, ShouldEqual, 1536669060000)
 				})
 
+				Convey("bucket bounds should be correct", func() {
+					So(res.Series[0].Name, ShouldEqual, "0")
+					So(res.Series[1].Name, ShouldEqual, "1")
+					So(res.Series[2].Name, ShouldEqual, "2")
+					So(res.Series[3].Name, ShouldEqual, "4")
+					So(res.Series[4].Name, ShouldEqual, "8")
+				})
+
 				Convey("value should be correct", func() {
 					So(res.Series[8].Points[0][0].Float64, ShouldEqual, 1)
 					So(res.Series[9].Points[0][0].Float64, ShouldEqual, 1)
@@ -383,6 +391,45 @@ func TestStackdriver(t *testing.T) {
 				})
 			})
 
+			Convey("when data from query is distribution with explicit bounds", func() {
+				data, err := loadTestFile("./test-data/4-series-response-distribution-explicit.json")
+				So(err, ShouldBeNil)
+				So(len(data.TimeSeries), ShouldEqual, 1)
+
+				res := &tsdb.QueryResult{Meta: simplejson.New(), RefId: "A"}
+				query := &StackdriverQuery{AliasBy: "{{bucket}}"}
+				err = executor.parseResponse(res, data, query)
+				So(err, ShouldBeNil)
+
+				So(len(res.Series), ShouldEqual, 33)
+				for i := 0; i < 33; i++ {
+					if i == 0 {
+						So(res.Series[i].Name, ShouldEqual, "0")
+					}
+					So(len(res.Series[i].Points), ShouldEqual, 2)
+				}
+
+				Convey("timestamps should be in ascending order", func() {
+					So(res.Series[0].Points[0][1].Float64, ShouldEqual, 1550859086000)
+					So(res.Series[0].Points[1][1].Float64, ShouldEqual, 1550859146000)
+				})
+
+				Convey("bucket bounds should be correct", func() {
+					So(res.Series[0].Name, ShouldEqual, "0")
+					So(res.Series[1].Name, ShouldEqual, "0.01")
+					So(res.Series[2].Name, ShouldEqual, "0.05")
+					So(res.Series[3].Name, ShouldEqual, "0.1")
+				})
+
+				Convey("value should be correct", func() {
+					So(res.Series[8].Points[0][0].Float64, ShouldEqual, 381)
+					So(res.Series[9].Points[0][0].Float64, ShouldEqual, 212)
+					So(res.Series[10].Points[0][0].Float64, ShouldEqual, 56)
+					So(res.Series[8].Points[1][0].Float64, ShouldEqual, 375)
+					So(res.Series[9].Points[1][0].Float64, ShouldEqual, 213)
+					So(res.Series[10].Points[1][0].Float64, ShouldEqual, 56)
+				})
+			})
 		})
 
 		Convey("when interpolating filter wildcards", func() {

pkg/tsdb/stackdriver/test-data/4-series-response-distribution-explicit.json

@@ -0,0 +1,209 @@
+{
+  "timeSeries": [
+    {
+      "metric": {
+        "type": "custom.googleapis.com\/opencensus\/grpc.io\/client\/roundtrip_latency"
+      },
+      "resource": {
+        "type": "global",
+        "labels": {
+          "project_id": "grafana-demo"
+        }
+      },
+      "metricKind": "DELTA",
+      "valueType": "DISTRIBUTION",
+      "points": [
+        {
+          "interval": {
+            "startTime": "2019-02-22T18:11:26Z",
+            "endTime": "2019-02-22T18:12:26Z"
+          },
+          "value": {
+            "distributionValue": {
+              "count": "1878",
+              "mean": 17.813718392255,
+              "sumOfSquaredDeviation": 7141630.651914,
+              "bucketOptions": {
+                "explicitBuckets": {
+                  "bounds": [
+                    0,
+                    0.01,
+                    0.05,
+                    0.1,
+                    0.3,
+                    0.6,
+                    0.8,
+                    1,
+                    2,
+                    3,
+                    4,
+                    5,
+                    6,
+                    8,
+                    10,
+                    13,
+                    16,
+                    20,
+                    25,
+                    30,
+                    40,
+                    50,
+                    65,
+                    80,
+                    100,
+                    130,
+                    160,
+                    200,
+                    250,
+                    300,
+                    400,
+                    500,
+                    650,
+                    800,
+                    1000,
+                    2000,
+                    5000,
+                    10000,
+                    20000,
+                    50000,
+                    100000
+                  ]
+                }
+              },
+              "bucketCounts": [
+                "0",
+                "0",
+                "0",
+                "0",
+                "8",
+                "403",
+                "297",
+                "184",
+                "375",
+                "213",
+                "56",
+                "31",
+                "15",
+                "13",
+                "4",
+                "1",
+                "5",
+                "2",
+                "8",
+                "13",
+                "26",
+                "13",
+                "45",
+                "48",
+                "61",
+                "10",
+                "3",
+                "6",
+                "7",
+                "4",
+                "7",
+                "12",
+                "8"
+              ]
+            }
+          }
+        },
+        {
+          "interval": {
+            "startTime": "2019-02-22T18:10:26Z",
+            "endTime": "2019-02-22T18:11:26Z"
+          },
+          "value": {
+            "distributionValue": {
+              "count": "1887",
+              "mean": 17.654277577766,
+              "sumOfSquaredDeviation": 7082587.2133073,
+              "bucketOptions": {
+                "explicitBuckets": {
+                  "bounds": [
+                    0,
+                    0.01,
+                    0.05,
+                    0.1,
+                    0.3,
+                    0.6,
+                    0.8,
+                    1,
+                    2,
+                    3,
+                    4,
+                    5,
+                    6,
+                    8,
+                    10,
+                    13,
+                    16,
+                    20,
+                    25,
+                    30,
+                    40,
+                    50,
+                    65,
+                    80,
+                    100,
+                    130,
+                    160,
+                    200,
+                    250,
+                    300,
+                    400,
+                    500,
+                    650,
+                    800,
+                    1000,
+                    2000,
+                    5000,
+                    10000,
+                    20000,
+                    50000,
+                    100000
+                  ]
+                }
+              },
+              "bucketCounts": [
+                "0",
+                "0",
+                "0",
+                "0",
+                "8",
+                "404",
+                "298",
+                "187",
+                "381",
+                "212",
+                "56",
+                "31",
+                "15",
+                "14",
+                "4",
+                "1",
+                "4",
+                "2",
+                "9",
+                "13",
+                "24",
+                "13",
+                "46",
+                "46",
+                "61",
+                "11",
+                "3",
+                "6",
+                "7",
+                "5",
+                "7",
+                "11",
+                "8"
+              ]
+            }
+          }
+        }
+      ]
+    }
+  ]
+}

pkg/tsdb/stackdriver/types.go

@@ -26,7 +26,7 @@ type StackdriverBucketOptions struct {
 		Scale            float64 `json:"scale"`
 	} `json:"exponentialBuckets"`
 	ExplicitBuckets *struct {
-		Bounds []int64 `json:"bounds"`
+		Bounds []float64 `json:"bounds"`
 	} `json:"explicitBuckets"`
 }