Implement copyStream

Author: rsora

commands/daemon/debug.go

@@ -43,23 +43,32 @@ func (s *DebugService) Debug(stream dbg.Debug_DebugServer) error {
 		return fmt.Errorf("first message must contain debug request, not data")
 	}
 
+	// launch debug recipe attaching stdin and out to grpc streaming
+	resp, err := cmd.Debug(stream.Context(), req,
+		copyStream(func() ([]byte, error) {
+			command, err := stream.Recv()
+			return command.GetData(), err
+		}),
+		feedStream(func(data []byte) {
+			stream.Send(&dbg.DebugResp{Data: data})
+		}))
+	if err != nil {
+		return (err)
+	}
+	return stream.Send(resp)
+}
+
+func copyStream(streamIn func() ([]byte, error)) io.Reader {
+
 	r, w := io.Pipe()
 	go func() {
 		for {
-			if command, err := stream.Recv(); err != nil {
+			if data, err := streamIn(); err != nil {
 				return
-			} else if _, err := w.Write(command.GetData()); err != nil {
+			} else if _, err := w.Write(data); err != nil {
 				return
 			}
 		}
 	}()
-
-	// launch debug recipe attaching stdin and out to grpc streaming
-	resp, err := cmd.Debug(stream.Context(), req, r, feedStream(func(data []byte) {
-		stream.Send(&dbg.DebugResp{Data: data})
-	}))
-	if err != nil {
-		return (err)
-	}
-	return stream.Send(resp)
+	return r
 }