Add support for RemoteEndpoint in transport/client.

middleware/http/client.go

@@ -34,6 +34,7 @@ type Client struct {
 	httpTrace        bool
 	defaultTags      map[string]string
 	transportOptions []TransportOption
+	remoteEndpoint   *model.Endpoint
 }
 
 // ClientOption allows optional configuration of Client.
@@ -71,6 +72,13 @@ func TransportOptions(options ...TransportOption) ClientOption {
 	}
 }
 
+// WithRemoteEndpoint will set the remote endpoint for all spans.
+func WithRemoteEndpoint(remoteEndpoint *model.Endpoint) ClientOption {
+	return func(c *Client) {
+		c.remoteEndpoint = remoteEndpoint
+	}
+}
+
 // NewClient returns an HTTP Client adding Zipkin instrumentation around an
 // embedded standard Go http.Client.
 func NewClient(tracer *zipkin.Tracer, options ...ClientOption) (*Client, error) {
@@ -88,6 +96,7 @@ func NewClient(tracer *zipkin.Tracer, options ...ClientOption) (*Client, error)
 		// the following Client settings override provided transport settings.
 		RoundTripper(c.Client.Transport),
 		TransportTrace(c.httpTrace),
+		TransportRemoteEndpoint(c.remoteEndpoint),
 	)
 	transport, err := NewTransport(tracer, c.transportOptions...)
 	if err != nil {
@@ -106,7 +115,7 @@ func (c *Client) DoWithAppSpan(req *http.Request, name string) (res *http.Respon
 		parentContext = span.Context()
 	}
 
-	appSpan := c.tracer.StartSpan(name, zipkin.Parent(parentContext))
+	appSpan := c.tracer.StartSpan(name, zipkin.Parent(parentContext), zipkin.RemoteEndpoint(c.remoteEndpoint))
 
 	zipkin.TagHTTPMethod.Set(appSpan, req.Method)
 	zipkin.TagHTTPPath.Set(appSpan, req.URL.Path)

middleware/http/client_test.go

@@ -41,12 +41,14 @@ func TestHTTPClient(t *testing.T) {
 		"conf.timeout": "default",
 	}
 
+	remoteEndpoint, _ := zipkin.NewEndpoint("google-service", "1.2.3.4:80")
 	client, err := httpclient.NewClient(
 		tracer,
 		httpclient.WithClient(&http.Client{}),
 		httpclient.ClientTrace(true),
 		httpclient.ClientTags(clientTags),
 		httpclient.TransportOptions(httpclient.TransportTags(transportTags)),
+		httpclient.WithRemoteEndpoint(remoteEndpoint),
 	)
 	if err != nil {
 		t.Fatalf("unable to create http client: %+v", err)
@@ -65,6 +67,14 @@ func TestHTTPClient(t *testing.T) {
 		t.Errorf("Span Count want 2+, have %d", len(spans))
 	}
 
+	rep := spans[0].RemoteEndpoint
+	if rep == nil {
+		t.Errorf("Span remoteEndpoint must not nil")
+	}
+	if rep.ServiceName != remoteEndpoint.ServiceName {
+		t.Errorf("Span remoteEndpoint ServiceName want %s, have %s", remoteEndpoint.ServiceName, rep.ServiceName)
+	}
+
 	req, _ = http.NewRequest("GET", "https://www.google.com", nil)
 
 	res, err = client.Do(req)

middleware/http/transport.go

@@ -58,6 +58,7 @@ type transport struct {
 	errResponseReader *ErrResponseReader
 	logger            *log.Logger
 	requestSampler    RequestSamplerFunc
+	remoteEndpoint    *model.Endpoint
 }
 
 // TransportOption allows one to configure optional transport configuration.
@@ -100,6 +101,13 @@ func TransportErrResponseReader(r ErrResponseReader) TransportOption {
 	}
 }
 
+// TransportRemoteEndpoint will set the remote endpoint for all spans.
+func TransportRemoteEndpoint(remoteEndpoint *model.Endpoint) TransportOption {
+	return func(c *transport) {
+		c.remoteEndpoint = remoteEndpoint
+	}
+}
+
 // TransportLogger allows to plug a logger into the transport
 func TransportLogger(l *log.Logger) TransportOption {
 	return func(t *transport) {
@@ -143,7 +151,7 @@ func NewTransport(tracer *zipkin.Tracer, options ...TransportOption) (http.Round
 // RoundTrip satisfies the RoundTripper interface.
 func (t *transport) RoundTrip(req *http.Request) (res *http.Response, err error) {
 	sp, _ := t.tracer.StartSpanFromContext(
-		req.Context(), req.URL.Scheme+"/"+req.Method, zipkin.Kind(model.Client),
+		req.Context(), req.URL.Scheme+"/"+req.Method, zipkin.Kind(model.Client), zipkin.RemoteEndpoint(t.remoteEndpoint),
 	)
 
 	for k, v := range t.defaultTags {