Properly document logger option; change default to logger

We now require OTP-21+ therefore there's no need to keep
the default of error_logger.

doc/src/manual/ranch.asciidoc

@@ -96,6 +96,10 @@ handshake_timeout (5000)::
 
 Maximum allowed time for the `ranch:handshake/1,2` call to finish.
 
+logger (logger)::
+
+The module that will be used to write log messages.
+
 max_connections (1024)::
 
 Maximum number of active connections per connection supervisor.
@@ -135,8 +139,10 @@ Unique name used to refer to a listener.
 * *2.0*: The option `max_connections` is now per connection supervisor.
 * *2.0*: The `num_conns_sup` option was added.
 * *2.0*: The `socket` option was removed.
+* *2.0*: The `logger` option is no longer experimental. It now defaults
+         to `logger` instead of `error_logger`.
 * *2.0*: The `opt()` type was removed.
-* *1.6*: The `logger` option was added.
+* *1.6*: The experimental `logger` option was added.
 * *1.6*: The `opt()` type was deprecated in favor of the new `opts()` type.
 
 == See also

src/ranch.erl

@@ -379,7 +379,7 @@ filter_user_options([], _) ->
 
 filter_options_warning(Opt) ->
 	Logger = case get(logger) of
-		undefined -> error_logger;
+		undefined -> logger;
 		Logger0 -> Logger0
 	end,
 	log(warning,
@@ -416,9 +416,8 @@ log(Level, Format, Args, #{logger := Logger})
 		when Logger =/= error_logger ->
 	_ = Logger:Level(Format, Args),
 	ok;
-%% We use error_logger by default. Because error_logger does
-%% not have all the levels we accept we have to do some
-%% mapping to error_logger functions.
+%% Because error_logger does not have all the levels
+%% we accept we have to do some mapping to error_logger functions.
 log(Level, Format, Args, _) ->
 	Function = case Level of
 		emergency -> error_msg;

src/ranch_acceptors_sup.erl

@@ -25,7 +25,7 @@ start_link(Ref, NumAcceptors, Transport) ->
 
 init([Ref, NumAcceptors, Transport]) ->
 	TransOpts = ranch_server:get_transport_options(Ref),
-	Logger = maps:get(logger, TransOpts, error_logger),
+	Logger = maps:get(logger, TransOpts, logger),
 	NumListenSockets = maps:get(num_listen_sockets, TransOpts, 1),
 	SocketOpts = maps:get(socket_opts, TransOpts, []),
 	%% We temporarily put the logger in the process dictionary

src/ranch_conns_sup.erl

@@ -108,7 +108,7 @@ init(Parent, Ref, Id, Transport, Protocol) ->
 	ConnType = maps:get(connection_type, TransOpts, worker),
 	Shutdown = maps:get(shutdown, TransOpts, 5000),
 	HandshakeTimeout = maps:get(handshake_timeout, TransOpts, 5000),
-	Logger = maps:get(logger, TransOpts, error_logger),
+	Logger = maps:get(logger, TransOpts, logger),
 	ProtoOpts = ranch_server:get_protocol_options(Ref),
 	ok = proc_lib:init_ack(Parent, {ok, self()}),
 	loop(#state{parent=Parent, ref=Ref, conn_type=ConnType,