Loki: Refactor getting of panel/dashboard title headers as part of decoupling (#106829)

* Loki: Refactor getting of panel/dashboard title headers as part of decoupling

* Add headers to be passed to api server

* Address review comments

pkg/registry/apis/query/header_utils.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	"github.com/grafana/grafana/pkg/services/ngalert/models"
+	queryService "github.com/grafana/grafana/pkg/services/query"
 )
 
 // Set of headers that we want to forward to the datasource api servers. Those are used i.e. for
@@ -13,18 +14,29 @@ import (
 // The headers related to grafana alerting (x-rule-*), should match the list at
 // https://github.com/grafana/grafana/blob/f8ae71e4583499dd461ebaed31451966be04220b/pkg/services/pluginsintegration/clientmiddleware/usealertingheaders_middleware.go#L23
 //
+// The headers related to grafana query should match the list at
+// https://github.com/grafana/grafana/blob/f8ae71e4583499dd461ebaed31451966be04220b/pkg/services/pluginsintegration/clientmiddleware/tracing_header_middleware.go#L36
+//
 // The usage of strings.ToLower is because the server would convert `FromAlert` to `Fromalert`. So the make matching
 // easier, we just match all headers in lower case.
 var expectedHeaders = map[string]string{
-	strings.ToLower(models.FromAlertHeaderName): models.FromAlertHeaderName,
-	strings.ToLower(models.CacheSkipHeaderName): models.CacheSkipHeaderName,
-	strings.ToLower("X-Rule-Name"):              "X-Rule-Name",
-	strings.ToLower("X-Rule-Uid"):               "X-Rule-Uid",
-	strings.ToLower("X-Rule-Folder"):            "X-Rule-Folder",
-	strings.ToLower("X-Rule-Source"):            "X-Rule-Source",
-	strings.ToLower("X-Rule-Type"):              "X-Rule-Type",
-	strings.ToLower("X-Rule-Version"):           "X-Rule-Version",
-	strings.ToLower("X-Grafana-Org-Id"):         "X-Grafana-Org-Id",
+	strings.ToLower(models.FromAlertHeaderName):        models.FromAlertHeaderName,
+	strings.ToLower(models.CacheSkipHeaderName):        models.CacheSkipHeaderName,
+	strings.ToLower("X-Rule-Name"):                     "X-Rule-Name",
+	strings.ToLower("X-Rule-Uid"):                      "X-Rule-Uid",
+	strings.ToLower("X-Rule-Folder"):                   "X-Rule-Folder",
+	strings.ToLower("X-Rule-Source"):                   "X-Rule-Source",
+	strings.ToLower("X-Rule-Type"):                     "X-Rule-Type",
+	strings.ToLower("X-Rule-Version"):                  "X-Rule-Version",
+	strings.ToLower("X-Grafana-Org-Id"):                "X-Grafana-Org-Id",
+	strings.ToLower(queryService.HeaderQueryGroupID):   queryService.HeaderQueryGroupID,
+	strings.ToLower(queryService.HeaderPanelID):        queryService.HeaderPanelID,
+	strings.ToLower(queryService.HeaderDashboardUID):   queryService.HeaderDashboardUID,
+	strings.ToLower(queryService.HeaderDatasourceUID):  queryService.HeaderDatasourceUID,
+	strings.ToLower(queryService.HeaderFromExpression): queryService.HeaderFromExpression,
+	strings.ToLower(queryService.HeaderPanelPluginId):  queryService.HeaderPanelPluginId,
+	strings.ToLower(queryService.HeaderDashboardTitle): queryService.HeaderDashboardTitle,
+	strings.ToLower(queryService.HeaderPanelTitle):     queryService.HeaderPanelTitle,
 }
 
 func ExtractKnownHeaders(header http.Header) map[string]string {

pkg/services/pluginsintegration/clientmiddleware/tracing_header_middleware.go

@@ -33,7 +33,17 @@ func (m *TracingHeaderMiddleware) applyHeaders(ctx context.Context, req backend.
 		return
 	}
 
-	var headersList = []string{query.HeaderQueryGroupID, query.HeaderPanelID, query.HeaderDashboardUID, query.HeaderDatasourceUID, query.HeaderFromExpression, `X-Grafana-Org-Id`, query.HeaderPanelPluginId}
+	var headersList = []string{
+		query.HeaderQueryGroupID,
+		query.HeaderPanelID,
+		query.HeaderDashboardUID,
+		query.HeaderDatasourceUID,
+		query.HeaderFromExpression,
+		`X-Grafana-Org-Id`,
+		query.HeaderPanelPluginId,
+		query.HeaderDashboardTitle,
+		query.HeaderPanelTitle,
+	}
 
 	for _, headerName := range headersList {
 		gotVal := reqCtx.Req.Header.Get(headerName)

pkg/services/query/query.go

@@ -29,10 +29,12 @@ import (
 )
 
 const (
-	HeaderPluginID       = "X-Plugin-Id"      // can be used for routing
-	HeaderDatasourceUID  = "X-Datasource-Uid" // can be used for routing/ load balancing
-	HeaderDashboardUID   = "X-Dashboard-Uid"  // mainly useful for debugging slow queries
-	HeaderPanelID        = "X-Panel-Id"       // mainly useful for debugging slow queries
+	HeaderPluginID       = "X-Plugin-Id"       // can be used for routing
+	HeaderDatasourceUID  = "X-Datasource-Uid"  // can be used for routing/ load balancing
+	HeaderDashboardUID   = "X-Dashboard-Uid"   // mainly useful for debugging slow queries
+	HeaderPanelID        = "X-Panel-Id"        // mainly useful for debugging slow queries
+	HeaderDashboardTitle = "X-Dashboard-Title" // used for identifying the dashboard with heavy query load
+	HeaderPanelTitle     = "X-Panel-Title"     // used for identifying the panel with heavy query load
 	HeaderPanelPluginId  = "X-Panel-Plugin-Id"
 	HeaderQueryGroupID   = "X-Query-Group-Id"    // mainly useful for finding related queries with query chunking
 	HeaderFromExpression = "X-Grafana-From-Expr" // used by datasources to identify expression queries

pkg/tsdb/loki/loki.go

@@ -24,7 +24,6 @@ import (
 
 	"github.com/grafana/grafana/pkg/infra/tracing"
 	"github.com/grafana/grafana/pkg/promlib/models"
-	"github.com/grafana/grafana/pkg/services/contexthandler"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
 	ngalertmodels "github.com/grafana/grafana/pkg/services/ngalert/models"
 	"github.com/grafana/grafana/pkg/tsdb/loki/kinds/dataquery"
@@ -56,9 +55,6 @@ var (
 	stagePrepareRequest  = "prepareRequest"
 	stageDatabaseRequest = "databaseRequest"
 	stageParseResponse   = "parseResponse"
-
-	dashboardTitleHeader = "X-Dashboard-Title"
-	panelTitleHeader     = "X-Panel-Title"
 )
 
 type datasourceInfo struct {
@@ -184,30 +180,9 @@ func (s *Service) QueryData(ctx context.Context, req *backend.QueryDataRequest)
 		logsDataplane: isFeatureEnabled(ctx, featuremgmt.FlagLokiLogsDataplane),
 	}
 
-	if isFeatureEnabled(ctx, featuremgmt.FlagLokiSendDashboardPanelNames) {
-		s.applyHeaders(ctx, req)
-	}
-
 	return queryData(ctx, req, dsInfo, responseOpts, s.tracer, logger, isFeatureEnabled(ctx, featuremgmt.FlagLokiRunQueriesInParallel), isFeatureEnabled(ctx, featuremgmt.FlagLokiStructuredMetadata), isFeatureEnabled(ctx, featuremgmt.FlagLogQLScope))
 }
 
-func (s *Service) applyHeaders(ctx context.Context, req backend.ForwardHTTPHeaders) {
-	reqCtx := contexthandler.FromContext(ctx)
-	if req == nil || reqCtx == nil || reqCtx.Req == nil {
-		return
-	}
-
-	var hList = []string{dashboardTitleHeader, panelTitleHeader}
-
-	for _, hName := range hList {
-		hVal := reqCtx.Req.Header.Get(hName)
-		if hVal == "" {
-			continue
-		}
-		req.SetHTTPHeader(hName, hVal)
-	}
-}
-
 func queryData(ctx context.Context, req *backend.QueryDataRequest, dsInfo *datasourceInfo, responseOpts ResponseOpts, tracer tracing.Tracer, plog log.Logger, runInParallel bool, requestStructuredMetadata, logQLScopes bool) (*backend.QueryDataResponse, error) {
 	result := backend.NewQueryDataResponse()