api: new v2 metrics query endpoint

Requests to endpoint will currently will error unless expressions feature flag is true.

Co-authored-by: Sofia Papagiannaki <papagian@gmail.com>

pkg/api/api.go

@@ -327,6 +327,7 @@ func (hs *HTTPServer) registerRoutes() {
 
 		// metrics
 		apiRoute.Post("/tsdb/query", bind(dtos.MetricRequest{}), Wrap(hs.QueryMetrics))
+		apiRoute.Post("/tsdb/query/v2", bind(dtos.MetricRequest{}), Wrap(hs.QueryMetricsV2))
 		apiRoute.Get("/tsdb/testdata/scenarios", Wrap(GetTestDataScenarios))
 		apiRoute.Get("/tsdb/testdata/gensql", reqGrafanaAdmin, Wrap(GenerateSQLTestData))
 		apiRoute.Get("/tsdb/testdata/random-walk", Wrap(GetTestDataRandomWalk))

pkg/api/metrics.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"sort"
 
+	"github.com/grafana/grafana/pkg/setting"
+
 	"github.com/grafana/grafana/pkg/api/dtos"
 	"github.com/grafana/grafana/pkg/bus"
 	"github.com/grafana/grafana/pkg/components/simplejson"
@@ -13,6 +15,69 @@ import (
 	"github.com/grafana/grafana/pkg/util"
 )
 
+// POST /api/tsdb/query/v2
+func (hs *HTTPServer) QueryMetricsV2(c *m.ReqContext, reqDto dtos.MetricRequest) Response {
+	if !setting.IsExpressionsEnabled() {
+		return Error(404, "Expressions feature toggle is not enabled", nil)
+	}
+
+	timeRange := tsdb.NewTimeRange(reqDto.From, reqDto.To)
+
+	if len(reqDto.Queries) == 0 {
+		return Error(400, "No queries found in query", nil)
+	}
+
+	var datasourceID int64
+	for _, query := range reqDto.Queries {
+		name, err := query.Get("datasource").String()
+		if err != nil {
+			return Error(500, "datasource missing name", err)
+		}
+		datasourceID, err = query.Get("datasourceId").Int64()
+		if err != nil {
+			return Error(400, "GEL datasource missing ID", nil)
+		}
+		if name == "-- GEL --" {
+			break
+		}
+	}
+	ds, err := hs.DatasourceCache.GetDatasource(datasourceID, c.SignedInUser, c.SkipCache)
+	if err != nil {
+		if err == m.ErrDataSourceAccessDenied {
+			return Error(403, "Access denied to datasource", err)
+		}
+		return Error(500, "Unable to load datasource meta data", err)
+	}
+
+	request := &tsdb.TsdbQuery{TimeRange: timeRange, Debug: reqDto.Debug}
+
+	for _, query := range reqDto.Queries {
+		request.Queries = append(request.Queries, &tsdb.Query{
+			RefId:         query.Get("refId").MustString("A"),
+			MaxDataPoints: query.Get("maxDataPoints").MustInt64(100),
+			IntervalMs:    query.Get("intervalMs").MustInt64(1000),
+			Model:         query,
+			DataSource:    ds,
+		})
+	}
+
+	resp, err := tsdb.HandleRequest(c.Req.Context(), ds, request)
+	if err != nil {
+		return Error(500, "Metric request error", err)
+	}
+
+	statusCode := 200
+	for _, res := range resp.Results {
+		if res.Error != nil {
+			res.ErrorString = res.Error.Error()
+			resp.Message = res.ErrorString
+			statusCode = 400
+		}
+	}
+
+	return JSON(statusCode, &resp)
+}
+
 // POST /api/tsdb/query
 func (hs *HTTPServer) QueryMetrics(c *m.ReqContext, reqDto dtos.MetricRequest) Response {
 	timeRange := tsdb.NewTimeRange(reqDto.From, reqDto.To)