%%%-------------------------------------------------------------------
%%% File : elixir_logger_backend.erl
%%% Author : Mickael Remond <mremond@process-one.net>
%%% Purpose : This module bridges lager logs to Elixir Logger.
%%% Created : 9 March 2016 by Mickael Remond <mremond@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2022 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License along
%%% with this program; if not, write to the Free Software Foundation, Inc.,
%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
%%%
%%%-------------------------------------------------------------------
-module(elixir_logger_backend).
-ifdef(ELIXIR_ENABLED).
-ifdef(LAGER).
-behaviour(gen_event).
-export([init/1, handle_call/2, handle_event/2, handle_info/2, terminate/2,
code_change/3]).
-record(state, {level = debug}).
init(Opts) ->
Level = proplists:get_value(level, Opts, debug),
State = #state{level = Level},
{ok, State}.
%% @private
handle_event({log, LagerMsg}, State) ->
#{mode := Mode, truncate := Truncate, level := MinLevel, utc_log := UTCLog} = 'Elixir.Logger.Config':'__data__'(),
MsgLevel = severity_to_level(lager_msg:severity(LagerMsg)),
case {lager_util:is_loggable(LagerMsg, lager_util:level_to_num(State#state.level), ?MODULE),
'Elixir.Logger':compare_levels(MsgLevel, MinLevel)} of
{_, lt}->
{ok, State};
{true, _} ->
Metadata = normalize_pid(lager_msg:metadata(LagerMsg)),
Message = 'Elixir.Logger.Utils':truncate(lager_msg:message(LagerMsg), Truncate),
Timestamp = timestamp(lager_msg:timestamp(LagerMsg), UTCLog),
GroupLeader = case proplists:get_value(pid, Metadata, self()) of
Pid when is_pid(Pid) ->
erlang:process_info(self(), group_leader);
_ -> {group_leader, self()}
end,
notify(Mode, {MsgLevel, GroupLeader, {'Elixir.Logger', Message, Timestamp, Metadata}}),
{ok, State};
_ ->
{ok, State}
end;
handle_event(_Msg, State) ->
{ok, State}.
%% @private
%% TODO Handle loglevels
handle_call(get_loglevel, State) ->
{ok, lager_util:config_to_mask(State#state.level), State};
handle_call({set_loglevel, Config}, State) ->
{ok, ok, State#state{level = Config}}.
%% @private
handle_info(_Msg, State) ->
{ok, State}.
%% @private
terminate(_Reason, _State) ->
ok.
%% @private
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
notify(sync, Msg) ->
gen_event:sync_notify('Elixir.Logger', Msg);
notify(async, Msg) ->
gen_event:notify('Elixir.Logger', Msg).
normalize_pid(Metadata) ->
case proplists:get_value(pid, Metadata) of
Pid when is_pid(Pid) -> Metadata;
Pid when is_list(Pid) ->
M1 = proplists:delete(pid, Metadata),
case catch erlang:list_to_pid(Pid) of
{'EXIT', _} ->
M1;
PidAsPid ->
[{pid, PidAsPid}|M1]
end;
_ ->
proplists:delete(pid, Metadata)
end.
%% Return timestamp with milliseconds
timestamp(Time, UTCLog) ->
{_, _, Micro} = erlang:timestamp(),
{Date, {Hours, Minutes, Seconds}} =
case UTCLog of
true -> calendar:now_to_universal_time(Time);
false -> calendar:now_to_local_time(Time)
end,
{Date, {Hours, Minutes, Seconds, Micro div 1000}}.
severity_to_level(debug) -> debug;
severity_to_level(info) -> info;
severity_to_level(notice) -> info;
severity_to_level(warning) -> warn;
severity_to_level(error) -> error;
severity_to_level(critical) -> error;
severity_to_level(alert) -> error;
severity_to_level(emergency) -> error.
-endif.
-endif.
