feat: trace http.status_code (#2708)

* feat: trace http.status_code

* feat: implements http.Flusher & http.Hijacker for traceResponseWriter

* test: delete notTracingSpans after test

* feat: trace http.status_code

* feat: implements http.Flusher & http.Hijacker for traceResponseWriter

* test: delete notTracingSpans after test

* refactor: update trace handler span message

* fix: code conflict

rest/handler/tracinghandler_test.go

@@ -2,8 +2,10 @@ package handler
 
 import (
 	"context"
+	"io"
 	"net/http"
 	"net/http/httptest"
+	"strconv"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -59,8 +61,10 @@ func TestDontTracingSpan(t *testing.T) {
 		Batcher:  "jaeger",
 		Sampler:  1.0,
 	})
+	defer ztrace.StopAgent()
 
 	DontTraceSpan("bar")
+	defer notTracingSpans.Delete("bar")
 
 	for _, test := range []string{"", "bar", "foo"} {
 		t.Run(test, func(t *testing.T) {
@@ -97,3 +101,50 @@ func TestDontTracingSpan(t *testing.T) {
 		})
 	}
 }
+
+func TestTraceResponseWriter(t *testing.T) {
+	ztrace.StartAgent(ztrace.Config{
+		Name:     "go-zero-test",
+		Endpoint: "http://localhost:14268/api/traces",
+		Batcher:  "jaeger",
+		Sampler:  1.0,
+	})
+	defer ztrace.StopAgent()
+
+	for _, test := range []int{0, 200, 300, 400, 401, 500, 503} {
+		t.Run(strconv.Itoa(test), func(t *testing.T) {
+			h := chain.New(TracingHandler("foo", "bar")).Then(
+				http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					span := trace.SpanFromContext(r.Context())
+					spanCtx := span.SpanContext()
+					assert.True(t, span.IsRecording())
+					assert.True(t, spanCtx.IsValid())
+					if test != 0 {
+						w.WriteHeader(test)
+					}
+					w.Write([]byte("hello"))
+				}))
+			ts := httptest.NewServer(h)
+			defer ts.Close()
+
+			client := ts.Client()
+			err := func(ctx context.Context) error {
+				ctx, span := otel.Tracer("httptrace/client").Start(ctx, "test")
+				defer span.End()
+
+				req, _ := http.NewRequest("GET", ts.URL, nil)
+				otel.GetTextMapPropagator().Inject(ctx, propagation.HeaderCarrier(req.Header))
+
+				res, err := client.Do(req)
+				assert.Nil(t, err)
+				resBody := make([]byte, 5)
+				_, err = res.Body.Read(resBody)
+				assert.Equal(t, io.EOF, err)
+				assert.Equal(t, []byte("hello"), resBody, "response body fail")
+				return res.Body.Close()
+			}(context.Background())
+
+			assert.Nil(t, err)
+		})
+	}
+}