Cloud Monitoring: set missing meta data for distribution type metrics (#45500)

* set missing meta data for distribution type metrics

* add test

* add test

* simplify custom set

* add test for executedQueryString

* add test data

* fix tests

* check group by

pkg/tsdb/cloudmonitoring/test-data/9-series-response-distribution-without-points.json

@@ -0,0 +1,17 @@
+{
+  "timeSeries": [
+    {
+      "metric": {
+        "type": "loadbalancing.googleapis.com\/https\/backend_latencies"
+      },
+      "resource": {
+        "type": "https_lb_rule",
+        "labels": {
+          "project_id": "grafana-prod"
+        }
+      },
+      "metricKind": "DELTA",
+      "valueType": "DISTRIBUTION"
+    }
+  ]
+}

pkg/tsdb/cloudmonitoring/time_series_filter.go

@@ -193,6 +193,9 @@ func (timeSeriesFilter *cloudMonitoringTimeSeriesFilter) parseResponse(queryRes
 							valueField,
 						},
 						RefID: timeSeriesFilter.RefID,
+						Meta: &data.FrameMeta{
+							ExecutedQueryString: executedQueryString,
+						},
 					}
 
 					if maxKey < i {
@@ -220,13 +223,20 @@ func (timeSeriesFilter *cloudMonitoringTimeSeriesFilter) parseResponse(queryRes
 							timeField,
 							valueField,
 						},
+						Meta: &data.FrameMeta{
+							ExecutedQueryString: executedQueryString,
+						},
 					}
 				}
 			}
 		}
 		for i := 0; i < len(buckets); i++ {
+			buckets[i].Meta.Custom = customFrameMeta
 			frames = append(frames, buckets[i])
 		}
+		if len(buckets) == 0 {
+			frames = append(frames, frame)
+		}
 	}
 	if len(response.TimeSeries) > 0 {
 		dl := timeSeriesFilter.buildDeepLink()

pkg/tsdb/cloudmonitoring/time_series_filter_test.go

@@ -11,6 +11,8 @@ import (
 	"time"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
+	sdkdata "github.com/grafana/grafana-plugin-sdk-go/data"
+
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -386,6 +388,77 @@ func TestTimeSeriesFilter(t *testing.T) {
 		require.True(t, ok)
 		assert.Equal(t, "114250375703598695", labels["resource.label.instance_id"])
 	})
+
+	t.Run("parseResponse successfully parses metadata for distribution valueType", func(t *testing.T) {
+		t.Run("exponential bounds", func(t *testing.T) {
+			data, err := loadTestFile("./test-data/3-series-response-distribution-exponential.json")
+			require.NoError(t, err)
+			assert.Equal(t, 1, len(data.TimeSeries))
+
+			res := &backend.DataResponse{}
+			require.NoError(t, (&cloudMonitoringTimeSeriesFilter{GroupBys: []string{"test_group_by"}}).parseResponse(res, data, "test_query"))
+
+			require.NotNil(t, res.Frames[0].Meta)
+			assert.Equal(t, sdkdata.FrameMeta{
+				ExecutedQueryString: "test_query",
+				Custom: map[string]interface{}{
+					"groupBys":        []string{"test_group_by"},
+					"alignmentPeriod": "",
+					"labels": map[string]string{
+						"resource.label.project_id": "grafana-prod",
+						"resource.type":             "https_lb_rule",
+					},
+					"perSeriesAligner": "",
+				},
+			}, *res.Frames[0].Meta)
+		})
+
+		t.Run("explicit bounds", func(t *testing.T) {
+			data, err := loadTestFile("./test-data/4-series-response-distribution-explicit.json")
+			require.NoError(t, err)
+			assert.Equal(t, 1, len(data.TimeSeries))
+
+			res := &backend.DataResponse{}
+			require.NoError(t, (&cloudMonitoringTimeSeriesFilter{GroupBys: []string{"test_group_by"}}).parseResponse(res, data, "test_query"))
+
+			require.NotNil(t, res.Frames[0].Meta)
+			assert.Equal(t, sdkdata.FrameMeta{
+				ExecutedQueryString: "test_query",
+				Custom: map[string]interface{}{
+					"groupBys":        []string{"test_group_by"},
+					"alignmentPeriod": "",
+					"labels": map[string]string{
+						"resource.label.project_id": "grafana-demo",
+						"resource.type":             "global",
+					},
+					"perSeriesAligner": "",
+				},
+			}, *res.Frames[0].Meta)
+		})
+
+		t.Run("without series points", func(t *testing.T) {
+			data, err := loadTestFile("./test-data/3-series-response-distribution-exponential.json")
+			require.NoError(t, err)
+			assert.Equal(t, 1, len(data.TimeSeries))
+
+			res := &backend.DataResponse{}
+			require.NoError(t, (&cloudMonitoringTimeSeriesFilter{GroupBys: []string{"test_group_by"}}).parseResponse(res, data, "test_query"))
+
+			require.NotNil(t, res.Frames[0].Meta)
+			assert.Equal(t, sdkdata.FrameMeta{
+				ExecutedQueryString: "test_query",
+				Custom: map[string]interface{}{
+					"groupBys":        []string{"test_group_by"},
+					"alignmentPeriod": "",
+					"labels": map[string]string{
+						"resource.label.project_id": "grafana-prod",
+						"resource.type":             "https_lb_rule",
+					},
+					"perSeriesAligner": "",
+				},
+			}, *res.Frames[0].Meta)
+		})
+	})
 }
 
 func loadTestFile(path string) (cloudMonitoringResponse, error) {