Print traceID with request

Signed-off-by: Goutham Veeramachaneni <[email protected]>

middleware/http_tracing.go

@@ -5,6 +5,9 @@ import (
 
 	"github.com/opentracing-contrib/go-stdlib/nethttp"
 	"github.com/opentracing/opentracing-go"
+	ot "github.com/opentracing/opentracing-go"
+	jaeger "github.com/uber/jaeger-client-go"
+	"golang.org/x/net/context"
 )
 
 // Tracer is a middleware which traces incoming requests.
@@ -25,3 +28,16 @@ func (t Tracer) Wrap(next http.Handler) http.Handler {
 		maybeTracer.ServeHTTP(w, r)
 	})
 }
+
+func ExtractTraceID(ctx context.Context) (string, bool) {
+	sp := ot.SpanFromContext(ctx)
+	if sp == nil {
+		return "", false
+	}
+	sctx, ok := sp.Context().(jaeger.SpanContext)
+	if !ok {
+		return "", false
+	}
+
+	return sctx.TraceID().String(), true
+}

middleware/logging.go

@@ -17,6 +17,11 @@ type Log struct {
 
 // logWithRequest information from the request and context as fields.
 func (l Log) logWithRequest(r *http.Request) logging.Interface {
+	traceID, ok := ExtractTraceID(r.Context())
+	if ok {
+		l.Log = l.Log.WithField("traceID", traceID)
+	}
+
 	return user.LogWith(r.Context(), l.Log)
 }
 

server/server.go

@@ -139,15 +139,16 @@ func New(cfg Config) (*Server, error) {
 		RegisterInstrumentation(router)
 	}
 	httpMiddleware := []middleware.Interface{
+		middleware.Tracer{},
 		middleware.Log{
 			Log: log,
 		},
 		middleware.Instrument{
 			Duration:     requestDuration,
 			RouteMatcher: router,
 		},
-		middleware.Tracer{},
 	}
+
 	httpMiddleware = append(httpMiddleware, cfg.HTTPMiddleware...)
 	httpServer := &http.Server{
 		ReadTimeout:  cfg.HTTPServerReadTimeout,