feat:cli support custom grpc metadata

client/dtmgrpc/dtmgimp/utils.go

@@ -61,18 +61,18 @@ const dtmpre string = "dtm-"
 
 // TransInfo2Ctx add trans info to grpc context
 func TransInfo2Ctx(ctx context.Context, gid, transType, branchID, op, dtm string) context.Context {
-	md := metadata.Pairs(
+	nctx := ctx
+	if ctx == nil {
+		nctx = context.Background()
+	}
+	return metadata.AppendToOutgoingContext(
+		nctx,
 		dtmpre+"gid", gid,
 		dtmpre+"trans_type", transType,
 		dtmpre+"branch_id", branchID,
 		dtmpre+"op", op,
 		dtmpre+"dtm", dtm,
 	)
-	nctx := ctx
-	if ctx == nil {
-		nctx = context.Background()
-	}
-	return metadata.NewOutgoingContext(nctx, md)
 }
 
 // Map2Kvs map to metadata kv