Add error information to graphite queries tracing (#55249)

This commit extends graphite QueryData() instrumentation to include in
the traces information about possible errors.

I've added an attribute about the graphite response code as well as
records for errors if there are any.

pkg/tsdb/graphite/graphite.go

@@ -14,12 +14,12 @@ import (
 	"strings"
 	"time"
 
-	"go.opentelemetry.io/otel/attribute"
-
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	"github.com/grafana/grafana-plugin-sdk-go/backend/datasource"
 	"github.com/grafana/grafana-plugin-sdk-go/backend/instancemgmt"
 	"github.com/grafana/grafana-plugin-sdk-go/data"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
 
 	"github.com/grafana/grafana/pkg/components/simplejson"
 	"github.com/grafana/grafana/pkg/infra/httpclient"
@@ -153,22 +153,30 @@ func (s *Service) QueryData(ctx context.Context, req *backend.QueryDataRequest)
 	}
 
 	ctx, span := s.tracer.Start(ctx, "graphite query")
+	defer span.End()
+
 	span.SetAttributes("target", target, attribute.Key("target").String(target))
 	span.SetAttributes("from", from, attribute.Key("from").String(from))
 	span.SetAttributes("until", until, attribute.Key("until").String(until))
 	span.SetAttributes("datasource_id", dsInfo.Id, attribute.Key("datasource_id").Int64(dsInfo.Id))
 	span.SetAttributes("org_id", req.PluginContext.OrgID, attribute.Key("org_id").Int64(req.PluginContext.OrgID))
 
-	defer span.End()
 	s.tracer.Inject(ctx, graphiteReq.Header, span)
 
 	res, err := dsInfo.HTTPClient.Do(graphiteReq)
+	if res != nil {
+		span.SetAttributes("graphite.response.code", res.StatusCode, attribute.Key("graphite.response.code").Int(res.StatusCode))
+	}
 	if err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
 		return &result, err
 	}
 
 	frames, err := s.toDataFrames(res)
 	if err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
 		return &result, err
 	}