Google Cloud Trace intercept for gRPC

Pass google trace context in remote procedure calls. This allows parent-child tracing across multiple services.

Note: There is work in progress on googleapis/google-cloud-go#548 which will make this repo obsolete.

Client

Use the intercept.EnableGRPCTracingDialOption option to add google trace context to outgoing RPC calls made by the gRPC client.

import "github.com/harlow/grpc-google-cloud-trace/intercept"

func main() {
	// add tracing option to dial
	conn, err := grpc.Dial(
		address,
		intercept.EnableGRPCTracingDialOption,
	)
	if err != nil {
		log.Fatalf("did not connect: %v", err)
	}
	defer conn.Close()

	// ...
}

Server

Use the intercept.EnableGRPCTracingServerOption function to parse the google cloud context from the request metadata. The interceptor will set up a new child span of the requesting party.

import "github.com/harlow/grpc-google-cloud-trace/intercept"

func main() {
	// ...

	grpcServer := grpc.NewServer(
	  intercept.EnableGRPCTracingServerOption(traceClient),
  	)
 	pb.RegisterRouteGuideServer(grpcServer, newServer())
	grpcServer.Serve(lis)
}

Create new child spans from the request context:

func getNearbyPoints(ctx context.Context, lat, lon float64) []geo.Point {
	span := trace.FromContext(ctx).NewChild("getNearbyPoints")
	defer span.Finish()

	// ...
}

Credits

This codebase was heavily inspired by the following issues and repositories: