refactor(telemetry): Export transactions

apps/emqx_modules/src/emqx_telemetry.erl

@@ -54,6 +54,11 @@
 
 -export([official_version/1]).
 
+%% Internal exports (RPC)
+-export([
+    do_ensure_uuids/0
+]).
+
 %% internal export
 -export([read_raw_build_info/0]).
 
@@ -530,7 +535,14 @@ bin(B) when is_binary(B) ->
     B.
 
 ensure_uuids() ->
-    Txn = fun() ->
+    {atomic, {NodeUUID, ClusterUUID}} = mria:transaction(
+        ?TELEMETRY_SHARD, fun ?MODULE:do_ensure_uuids/0
+    ),
+    save_uuid_to_file(NodeUUID, node),
+    save_uuid_to_file(ClusterUUID, cluster),
+    {NodeUUID, ClusterUUID}.
+
+do_ensure_uuids() ->
     NodeUUID =
         case mnesia:wread({?TELEMETRY, node()}) of
             [] ->
@@ -571,11 +583,6 @@ ensure_uuids() ->
             [#telemetry{uuid = ClusterUUID0}] ->
                 ClusterUUID0
         end,
-        {NodeUUID, ClusterUUID}
-    end,
-    {atomic, {NodeUUID, ClusterUUID}} = mria:transaction(?TELEMETRY_SHARD, Txn),
-    save_uuid_to_file(NodeUUID, node),
-    save_uuid_to_file(ClusterUUID, cluster),
     {NodeUUID, ClusterUUID}.
 
 get_uuid_from_file(Type) ->