refactor: move ntoa (ip address formatting) code to emqx_utils

apps/emqx_management/src/emqx_mgmt_util.erl

@@ -61,10 +61,8 @@ kmg(Byte) ->
 kmg(F, S) ->
     iolist_to_binary(io_lib:format("~.2f~ts", [F, S])).
 
-ntoa({0, 0, 0, 0, 0, 16#ffff, AB, CD}) ->
-    inet_parse:ntoa({AB bsr 8, AB rem 256, CD bsr 8, CD rem 256});
-ntoa(IP) ->
-    inet_parse:ntoa(IP).
+ntoa(Ip) ->
+    emqx_utils:ntoa(Ip).
 
 merge_maps(Default, New) ->
     maps:fold(

apps/emqx_rule_engine/src/emqx_rule_events.erl

@@ -1039,9 +1039,10 @@ reason({shutdown, Reason}) when is_atom(Reason) -> Reason;
 reason({Error, _}) when is_atom(Error) -> Error;
 reason(_) -> internal_error.
 
-ntoa(undefined) -> undefined;
-ntoa({IpAddr, Port}) -> iolist_to_binary([inet:ntoa(IpAddr), ":", integer_to_list(Port)]);
-ntoa(IpAddr) -> iolist_to_binary(inet:ntoa(IpAddr)).
+ntoa(undefined) ->
+    undefined;
+ntoa(IpOrIpPort) ->
+    iolist_to_binary(emqx_utils:ntoa(IpOrIpPort)).
 
 event_name(?BRIDGE_HOOKPOINT(_) = Bridge) -> Bridge;
 event_name(<<"$events/client_connected">>) -> 'client.connected';

apps/emqx_utils/src/emqx_utils.erl

@@ -64,7 +64,8 @@
     tcp_keepalive_opts/4,
     format/1,
     format_mfal/1,
-    call_first_defined/1
+    call_first_defined/1,
+    ntoa/1
 ]).
 
 -export([
@@ -1031,6 +1032,15 @@ flatcomb(Ys = [_ | _], Zs = [_ | _]) ->
 flatcomb(Y, Zs) ->
     [Y | Zs].
 
+%% @doc Format IP address tuple or {IP, Port} tuple to string.
+ntoa({IP, Port}) ->
+    ntoa(IP) ++ ":" ++ integer_to_list(Port);
+ntoa({0, 0, 0, 0, 0, 16#ffff, AB, CD}) ->
+    %% v6 piggyback v4
+    inet_parse:ntoa({AB bsr 8, AB rem 256, CD bsr 8, CD rem 256});
+ntoa(IP) ->
+    inet_parse:ntoa(IP).
+
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").