Method initQueryFrontend

cmd/tempo/app/modules.go:464–530

()

}

func (t *App) initQueryFrontend() (services.Service, error) {
	// cortexTripper is a bridge between http and httpgrpc.
	// It does the job of passing data to the cortex frontend code.
	cortexTripper, v1, err := frontend.InitFrontend(t.cfg.Frontend.Config, log.Logger, prometheus.DefaultRegisterer)
	if err != nil {
		return nil, err
	}
	t.frontend = v1

	// create query frontend
	queryFrontend, err := frontend.New(t.cfg.Frontend, cortexTripper, t.Overrides, t.store, t.cacheProvider, t.cfg.HTTPAPIPrefix, t.HTTPAuthMiddleware, t.DataAccessController, log.Logger, prometheus.DefaultRegisterer)
	if err != nil {
		return nil, err
	}

	// register grpc server for queriers to connect to
	frontend_v1pb.RegisterFrontendServer(t.Server.GRPC(), t.frontend)
	// we register the streaming querier service on both the http and grpc servers. Grafana expects
	// this GRPC service to be available on the HTTP server.
	tempopb.RegisterStreamingQuerierServer(t.Server.GRPC(), queryFrontend)

	httpAPIMiddleware := []middleware.Interface{
		t.HTTPAuthMiddleware,
		httpGzipMiddleware(),
	}

	// use the api timeout for http requests if set. note that this is set in initServer() for
	// grpc requests
	if t.cfg.Frontend.APITimeout > 0 {
		httpAPIMiddleware = append(httpAPIMiddleware, middleware.NewTimeoutMiddleware(t.cfg.Frontend.APITimeout, "unable to process request in the configured timeout", kitlog.NewNopLogger()))
	}

	// wrap handlers with auth
	base := middleware.Merge(httpAPIMiddleware...)

	// http trace by id endpoint
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathTraces), base.Wrap(queryFrontend.TraceByIDHandler))
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathTracesV2), base.Wrap(queryFrontend.TraceByIDHandlerV2))

	// http search endpoints
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathSearch), base.Wrap(queryFrontend.SearchHandler))
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathSearchTags), base.Wrap(queryFrontend.SearchTagsHandler))
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathSearchTagsV2), base.Wrap(queryFrontend.SearchTagsV2Handler))
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathSearchTagValues), base.Wrap(queryFrontend.SearchTagsValuesHandler))
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathSearchTagValuesV2), base.Wrap(queryFrontend.SearchTagsValuesV2Handler))

	// http metrics endpoints
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathMetricsQueryInstant), base.Wrap(queryFrontend.MetricsQueryInstantHandler))
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathMetricsQueryRange), base.Wrap(queryFrontend.MetricsQueryRangeHandler))

	// http mcp endpoint
	t.Server.HTTPRouter().Handle(addHTTPAPIPrefix(&t.cfg, api.PathMCP), base.Wrap(queryFrontend.MCPHandler))

	// the query frontend needs to have knowledge of the blocks so it can shard search jobs
	if t.cfg.Target == QueryFrontend {
		t.store.EnablePolling(context.Background(), nil, false)
	}