rename ngin to rest

rest/handler/tracinghandler.go

@@ -0,0 +1,25 @@
+package handler
+
+import (
+	"net/http"
+
+	"zero/core/logx"
+	"zero/core/sysx"
+	"zero/core/trace"
+)
+
+func TracingHandler(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		carrier, err := trace.Extract(trace.HttpFormat, r.Header)
+		// ErrInvalidCarrier means no trace id was set in http header
+		if err != nil && err != trace.ErrInvalidCarrier {
+			logx.Error(err)
+		}
+
+		ctx, span := trace.StartServerSpan(r.Context(), carrier, sysx.Hostname(), r.RequestURI)
+		defer span.Finish()
+		r = r.WithContext(ctx)
+
+		next.ServeHTTP(w, r)
+	})
+}