Add opentracing spans to the HTTP RPC clients

src/github.com/matrix-org/dendrite/roomserver/api/alias.go

@@ -17,6 +17,8 @@ package api
 import (
 	"context"
 	"net/http"
+
+	opentracing "github.com/opentracing/opentracing-go"
 )
 
 // SetRoomAliasRequest is a request to SetRoomAlias
@@ -111,8 +113,11 @@ func (h *httpRoomserverAliasAPI) SetRoomAlias(
 	request *SetRoomAliasRequest,
 	response *SetRoomAliasResponse,
 ) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "SetRoomAlias")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverSetRoomAliasPath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
 
 // GetAliasRoomID implements RoomserverAliasAPI
@@ -121,8 +126,11 @@ func (h *httpRoomserverAliasAPI) GetAliasRoomID(
 	request *GetAliasRoomIDRequest,
 	response *GetAliasRoomIDResponse,
 ) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "GetAliasRoomID")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverGetAliasRoomIDPath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
 
 // RemoveRoomAlias implements RoomserverAliasAPI
@@ -131,6 +139,9 @@ func (h *httpRoomserverAliasAPI) RemoveRoomAlias(
 	request *RemoveRoomAliasRequest,
 	response *RemoveRoomAliasResponse,
 ) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "RemoveRoomAlias")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverRemoveRoomAliasPath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }

src/github.com/matrix-org/dendrite/roomserver/api/input.go

@@ -20,6 +20,7 @@ import (
 	"net/http"
 
 	"github.com/matrix-org/gomatrixserverlib"
+	opentracing "github.com/opentracing/opentracing-go"
 )
 
 const (
@@ -117,6 +118,9 @@ func (h *httpRoomserverInputAPI) InputRoomEvents(
 	request *InputRoomEventsRequest,
 	response *InputRoomEventsResponse,
 ) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "InputRoomEvents")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverInputRoomEventsPath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }

src/github.com/matrix-org/dendrite/roomserver/api/query.go

@@ -21,6 +21,10 @@ import (
 	"fmt"
 	"net/http"
 
+	"github.com/opentracing/opentracing-go/ext"
+
+	"github.com/opentracing/opentracing-go"
+
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
@@ -234,8 +238,11 @@ func (h *httpRoomserverQueryAPI) QueryLatestEventsAndState(
 	request *QueryLatestEventsAndStateRequest,
 	response *QueryLatestEventsAndStateResponse,
 ) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryLatestEventsAndState")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverQueryLatestEventsAndStatePath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
 
 // QueryStateAfterEvents implements RoomserverQueryAPI
@@ -244,8 +251,11 @@ func (h *httpRoomserverQueryAPI) QueryStateAfterEvents(
 	request *QueryStateAfterEventsRequest,
 	response *QueryStateAfterEventsResponse,
 ) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryStateAfterEvents")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverQueryStateAfterEventsPath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
 
 // QueryEventsByID implements RoomserverQueryAPI
@@ -254,8 +264,11 @@ func (h *httpRoomserverQueryAPI) QueryEventsByID(
 	request *QueryEventsByIDRequest,
 	response *QueryEventsByIDResponse,
 ) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryEventsByID")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverQueryEventsByIDPath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
 
 // QueryMembershipsForRoom implements RoomserverQueryAPI
@@ -264,8 +277,11 @@ func (h *httpRoomserverQueryAPI) QueryMembershipsForRoom(
 	request *QueryMembershipsForRoomRequest,
 	response *QueryMembershipsForRoomResponse,
 ) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryMembershipsForRoom")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverQueryMembershipsForRoomPath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
 
 // QueryInvitesForUser implements RoomserverQueryAPI
@@ -274,8 +290,11 @@ func (h *httpRoomserverQueryAPI) QueryInvitesForUser(
 	request *QueryInvitesForUserRequest,
 	response *QueryInvitesForUserResponse,
 ) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryInvitesForUser")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverQueryInvitesForUserPath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
 
 // QueryServerAllowedToSeeEvent implements RoomserverQueryAPI
@@ -284,12 +303,15 @@ func (h *httpRoomserverQueryAPI) QueryServerAllowedToSeeEvent(
 	request *QueryServerAllowedToSeeEventRequest,
 	response *QueryServerAllowedToSeeEventResponse,
 ) (err error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryServerAllowedToSeeEvent")
+	defer span.Finish()
+
 	apiURL := h.roomserverURL + RoomserverQueryServerAllowedToSeeEventPath
-	return postJSON(ctx, h.httpClient, apiURL, request, response)
+	return postJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
 
 func postJSON(
-	ctx context.Context, httpClient *http.Client,
+	ctx context.Context, span opentracing.Span, httpClient *http.Client,
 	apiURL string, request, response interface{},
 ) error {
 	jsonBytes, err := json.Marshal(request)
@@ -302,6 +324,15 @@ func postJSON(
 		return err
 	}
 
+	// Mark the span as being an RPC client.
+	ext.SpanKindRPCClient.Set(span)
+	carrier := opentracing.HTTPHeadersCarrier(req.Header)
+	tracer := opentracing.GlobalTracer()
+
+	if err = tracer.Inject(span.Context(), opentracing.HTTPHeaders, carrier); err != nil {
+		return err
+	}
+
 	req.Header.Set("Content-Type", "application/json")
 
 	res, err := httpClient.Do(req.WithContext(ctx))