Esempio n. 1
0
// New returns an AddService backed by an HTTP server living at the remote
// instance. We expect instance to come from a service discovery system, so
// likely of the form "host:port".
func New(instance string, tracer stdopentracing.Tracer, logger log.Logger) (addsvc.Service, error) {
	if !strings.HasPrefix(instance, "http") {
		instance = "http://" + instance
	}
	u, err := url.Parse(instance)
	if err != nil {
		return nil, err
	}

	// We construct a single ratelimiter middleware, to limit the total outgoing
	// QPS from this client to all methods on the remote instance. We also
	// construct per-endpoint circuitbreaker middlewares to demonstrate how
	// that's done, although they could easily be combined into a single breaker
	// for the entire remote instance, too.

	limiter := ratelimit.NewTokenBucketLimiter(jujuratelimit.NewBucketWithRate(100, 100))

	var sumEndpoint endpoint.Endpoint
	{
		sumEndpoint = httptransport.NewClient(
			"POST",
			copyURL(u, "/sum"),
			addsvc.EncodeHTTPGenericRequest,
			addsvc.DecodeHTTPSumResponse,
			httptransport.SetClientBefore(opentracing.FromHTTPRequest(tracer, "Sum", logger)),
		).Endpoint()
		sumEndpoint = opentracing.TraceClient(tracer, "Sum")(sumEndpoint)
		sumEndpoint = limiter(sumEndpoint)
		sumEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Sum",
			Timeout: 30 * time.Second,
		}))(sumEndpoint)
	}

	var concatEndpoint endpoint.Endpoint
	{
		concatEndpoint = httptransport.NewClient(
			"POST",
			copyURL(u, "/concat"),
			addsvc.EncodeHTTPGenericRequest,
			addsvc.DecodeHTTPConcatResponse,
			httptransport.SetClientBefore(opentracing.FromHTTPRequest(tracer, "Concat", logger)),
		).Endpoint()
		concatEndpoint = opentracing.TraceClient(tracer, "Concat")(concatEndpoint)
		concatEndpoint = limiter(concatEndpoint)
		sumEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Concat",
			Timeout: 30 * time.Second,
		}))(sumEndpoint)
	}

	return addsvc.Endpoints{
		SumEndpoint:    sumEndpoint,
		ConcatEndpoint: concatEndpoint,
	}, nil
}
Esempio n. 2
0
File: client.go Progetto: crezam/kit
// New returns an AddService backed by a gRPC client connection. It is the
// responsibility of the caller to dial, and later close, the connection.
func New(conn *grpc.ClientConn, tracer stdopentracing.Tracer, logger log.Logger) addsvc.Service {
	// We construct a single ratelimiter middleware, to limit the total outgoing
	// QPS from this client to all methods on the remote instance. We also
	// construct per-endpoint circuitbreaker middlewares to demonstrate how
	// that's done, although they could easily be combined into a single breaker
	// for the entire remote instance, too.

	limiter := ratelimit.NewTokenBucketLimiter(jujuratelimit.NewBucketWithRate(100, 100))

	var sumEndpoint endpoint.Endpoint
	{
		sumEndpoint = grpctransport.NewClient(
			conn,
			"Add",
			"Sum",
			addsvc.EncodeGRPCSumRequest,
			addsvc.DecodeGRPCSumResponse,
			pb.SumReply{},
			grpctransport.ClientBefore(opentracing.FromGRPCRequest(tracer, "Sum", logger)),
		).Endpoint()
		sumEndpoint = opentracing.TraceClient(tracer, "Sum")(sumEndpoint)
		sumEndpoint = limiter(sumEndpoint)
		sumEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Sum",
			Timeout: 30 * time.Second,
		}))(sumEndpoint)
	}

	var concatEndpoint endpoint.Endpoint
	{
		concatEndpoint = grpctransport.NewClient(
			conn,
			"Add",
			"Concat",
			addsvc.EncodeGRPCConcatRequest,
			addsvc.DecodeGRPCConcatResponse,
			pb.ConcatReply{},
			grpctransport.ClientBefore(opentracing.FromGRPCRequest(tracer, "Concat", logger)),
		).Endpoint()
		concatEndpoint = opentracing.TraceClient(tracer, "Concat")(concatEndpoint)
		concatEndpoint = limiter(concatEndpoint)
		concatEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Concat",
			Timeout: 30 * time.Second,
		}))(concatEndpoint)
	}

	return addsvc.Endpoints{
		SumEndpoint:    sumEndpoint,
		ConcatEndpoint: concatEndpoint,
	}
}
Esempio n. 3
0
func TestTraceClient(t *testing.T) {
	tracer := mocktracer.New()

	// Initialize the ctx with a parent Span.
	parentSpan := tracer.StartSpan("parent").(*mocktracer.MockSpan)
	defer parentSpan.Finish()
	ctx := opentracing.ContextWithSpan(context.Background(), parentSpan)

	tracedEndpoint := kitot.TraceClient(tracer, "testOp")(endpoint.Nop)
	if _, err := tracedEndpoint(ctx, struct{}{}); err != nil {
		t.Fatal(err)
	}

	// tracedEndpoint created a new Span.
	finishedSpans := tracer.FinishedSpans()
	if want, have := 1, len(finishedSpans); want != have {
		t.Fatalf("Want %v span(s), found %v", want, have)
	}

	endpointSpan := finishedSpans[0]
	if want, have := "testOp", endpointSpan.OperationName; want != have {
		t.Fatalf("Want %q, have %q", want, have)
	}

	parentContext := parentSpan.Context().(mocktracer.MockSpanContext)
	endpointContext := parentSpan.Context().(mocktracer.MockSpanContext)

	// ... and that the parent ID is set appropriately.
	if want, have := parentContext.SpanID, endpointContext.SpanID; want != have {
		t.Errorf("Want ParentID %q, have %q", want, have)
	}
}
Esempio n. 4
0
func TestTraceClientNoContextSpan(t *testing.T) {
	tracer := mocktracer.New()

	// Empty/background context.
	tracedEndpoint := kitot.TraceClient(tracer, "testOp")(endpoint.Nop)
	if _, err := tracedEndpoint(context.Background(), struct{}{}); err != nil {
		t.Fatal(err)
	}

	// tracedEndpoint created a new Span.
	finishedSpans := tracer.FinishedSpans()
	if want, have := 1, len(finishedSpans); want != have {
		t.Fatalf("Want %v span(s), found %v", want, have)
	}

	endpointSpan := finishedSpans[0]
	if want, have := "testOp", endpointSpan.OperationName; want != have {
		t.Fatalf("Want %q, have %q", want, have)
	}
}
Esempio n. 5
0
func buildEndpoint(tracer opentracing.Tracer, operationName string, instances []string, factory loadbalancer.Factory, seed int64, logger log.Logger) endpoint.Endpoint {
	publisher := static.NewPublisher(instances, factory, logger)
	random := loadbalancer.NewRandom(publisher, seed)
	endpoint := loadbalancer.Retry(10, 10*time.Second, random)
	return kitot.TraceClient(tracer, operationName)(endpoint)
}