Merge pull request #311 from rabbitmq/rotate-command

API to explicitly call log rotation

Reviewed-by: macintux

src/lager.erl

@@ -22,12 +22,14 @@
 
 -define(LAGER_MD_KEY, '__lager_metadata').
 -define(TRACE_SINK, '__trace_sink').
+-define(ROTATE_TIMEOUT, 100000).
 
 %% API
 -export([start/0,
         log/3, log/4, log/5,
         log_unsafe/4,
         md/0, md/1,
+        rotate_handler/1, rotate_handler/2, rotate_sink/1, rotate_all/0,
         trace/2, trace/3, trace_file/2, trace_file/3, trace_file/4, trace_console/1, trace_console/2,
         list_all_sinks/0, clear_all_traces/0, stop_trace/1, stop_trace/3, status/0,
         get_loglevel/1, get_loglevel/2, set_loglevel/2, set_loglevel/3, set_loglevel/4, get_loglevels/1,
@@ -606,3 +608,31 @@ pr_stacktrace(Stacktrace) ->
 pr_stacktrace(Stacktrace, {Class, Reason}) ->
     lists:flatten(
         pr_stacktrace(Stacktrace) ++ "\n" ++ io_lib:format("~s:~p", [Class, Reason])).
+    
+rotate_sink(Sink) ->
+    Handlers = lager_config:global_get(handlers),
+    RotateHandlers = lists:filtermap(
+        fun({Handler,_,S}) when S == Sink -> {true, {Handler, Sink}};
+           (_)                            -> false 
+        end, 
+        Handlers),
+    rotate_handlers(RotateHandlers).
+
+rotate_all() -> 
+    rotate_handlers(lists:map(fun({H,_,S}) -> {H, S} end,
+                              lager_config:global_get(handlers))).
+
+
+rotate_handlers(Handlers) ->
+    [ rotate_handler(Handler, Sink) || {Handler, Sink} <- Handlers ].
+
+
+rotate_handler(Handler) ->
+    Handlers = lager_config:global_get(handlers),
+    case lists:keyfind(Handler, 1, Handlers) of
+        {Handler, _, Sink} -> rotate_handler(Handler, Sink);
+        false              -> ok
+    end.
+
+rotate_handler(Handler, Sink) ->
+    gen_event:call(Sink, Handler, rotate, ?ROTATE_TIMEOUT).

src/lager_file_backend.erl

@@ -142,6 +142,9 @@ handle_call({set_loghwm, Hwm}, #state{shaper=Shaper, name=Name} = State) ->
             ?INT_LOG(notice, "Changed loghwm of ~s to ~p", [Name, Hwm]),
             {ok, {last_loghwm, Shaper#lager_shaper.hwm}, State#state{shaper=NewShaper}}
     end;
+handle_call(rotate, State = #state{name=File}) ->
+    {ok, NewState} = handle_info({rotate, File}, State),
+    {ok, ok, NewState};
 handle_call(_Request, State) ->
     {ok, ok, State}.
 
@@ -637,6 +640,16 @@ filesystem_test_() ->
                         ?assert(filelib:is_regular("test.log.0"))
                 end
             },
+            {"rotation call should work",
+                fun() ->
+                        gen_event:add_handler(lager_event, {lager_file_backend, "test.log"}, [{file, "test.log"}, {level, info}, {check_interval, 1000}]),
+                        lager:log(error, self(), "Test message1"),
+                        lager:log(error, self(), "Test message1"),
+                        gen_event:call(lager_event, {lager_file_backend, "test.log"}, rotate, infinity),
+                        lager:log(error, self(), "Test message1"),
+                        ?assert(filelib:is_regular("test.log.0")) 
+                end
+            },
             {"sync_on option should work",
                 fun() ->
                         gen_event:add_handler(lager_event, lager_file_backend, [{file, "test.log"}, {level, info}, {sync_on, "=info"}, {check_interval, 5000}, {sync_interval, 5000}]),

test/lager_rotate.erl

@@ -0,0 +1,138 @@
+-module(lager_rotate).
+
+-compile(export_all).
+
+-ifdef(TEST).
+-include_lib("eunit/include/eunit.hrl").
+-endif.
+
+
+rotate_test_() ->
+    {foreach,
+        fun() ->
+                file:write_file("test1.log", ""),
+                file:write_file("test2.log", ""),
+                file:write_file("test3.log", ""),
+                file:delete("test1.log.0"),
+                file:delete("test2.log.0"),
+                file:delete("test3.log.0"),
+                error_logger:tty(false),
+                application:load(lager),
+                application:set_env(lager, handlers, 
+                    [{lager_file_backend, [{file, "test1.log"}, {level, info}]},
+                     {lager_file_backend, [{file, "test2.log"}, {level, info}]}]),
+                application:set_env(lager, extra_sinks,
+                    [{sink_event, 
+                        [{handlers, 
+                            [{lager_file_backend, [{file, "test3.log"}, {level, info}]}]}
+                        ]}]),
+                application:set_env(lager, error_logger_redirect, false),
+                application:set_env(lager, async_threshold, undefined),
+                lager:start()
+        end,
+        fun(_) ->
+                file:delete("test1.log"),
+                file:delete("test2.log"),
+                file:delete("test3.log"),
+                file:delete("test1.log.0"),
+                file:delete("test2.log.0"),
+                file:delete("test3.log.0"),
+                application:stop(lager),
+                application:stop(goldrush),
+                error_logger:tty(true)
+        end,
+        [{"Rotate single file",
+            fun() ->
+                lager:log(error, self(), "Test message 1"),
+                lager:log(sink_event, error, self(), "Sink test message 1", []),
+                lager:rotate_handler({lager_file_backend, "test1.log"}),
+                timer:sleep(1000),
+                true = filelib:is_regular("test1.log.0"),
+                lager:log(error, self(), "Test message 2"),
+                lager:log(sink_event, error, self(), "Sink test message 2", []),
+                
+                {ok, File1} = file:read_file("test1.log"),
+                {ok, File2} = file:read_file("test2.log"),
+                {ok, SinkFile} = file:read_file("test3.log"),
+                {ok, File1Old} = file:read_file("test1.log.0"),
+
+                have_no_log(File1, <<"Test message 1">>),
+                have_log(File1, <<"Test message 2">>),
+
+                have_log(File2, <<"Test message 1">>),
+                have_log(File2, <<"Test message 2">>),
+
+                have_log(File1Old, <<"Test message 1">>),
+                have_no_log(File1Old, <<"Test message 2">>),
+
+                have_log(SinkFile, <<"Sink test message 1">>),
+                have_log(SinkFile, <<"Sink test message 2">>)
+            end},
+         {"Rotate sink",
+            fun() ->
+                lager:log(error, self(), "Test message 1"),
+                lager:log(sink_event, error, self(), "Sink test message 1", []),
+                lager:rotate_sink(sink_event),
+                timer:sleep(1000),
+                true = filelib:is_regular("test3.log.0"),
+                lager:log(error, self(), "Test message 2"),
+                lager:log(sink_event, error, self(), "Sink test message 2", []),
+                {ok, File1} = file:read_file("test1.log"),
+                {ok, File2} = file:read_file("test2.log"),
+                {ok, SinkFile} = file:read_file("test3.log"),
+                {ok, SinkFileOld} = file:read_file("test3.log.0"),
+
+                have_log(File1, <<"Test message 1">>),
+                have_log(File1, <<"Test message 2">>),
+
+                have_log(File2, <<"Test message 1">>),
+                have_log(File2, <<"Test message 2">>),
+
+                have_log(SinkFileOld, <<"Sink test message 1">>),
+                have_no_log(SinkFileOld, <<"Sink test message 2">>),
+
+                have_no_log(SinkFile, <<"Sink test message 1">>),
+                have_log(SinkFile, <<"Sink test message 2">>)
+            end},
+         {"Rotate all",
+            fun() ->
+                lager:log(error, self(), "Test message 1"),
+                lager:log(sink_event, error, self(), "Sink test message 1", []),
+                lager:rotate_all(),
+                timer:sleep(1000),
+                true = filelib:is_regular("test3.log.0"),
+                lager:log(error, self(), "Test message 2"),
+                lager:log(sink_event, error, self(), "Sink test message 2", []),
+                {ok, File1} = file:read_file("test1.log"),
+                {ok, File2} = file:read_file("test2.log"),
+                {ok, SinkFile} = file:read_file("test3.log"),
+                {ok, File1Old} = file:read_file("test1.log.0"),
+                {ok, File2Old} = file:read_file("test2.log.0"),
+                {ok, SinkFileOld} = file:read_file("test3.log.0"),
+
+                have_no_log(File1, <<"Test message 1">>),
+                have_log(File1, <<"Test message 2">>),
+
+                have_no_log(File2, <<"Test message 1">>),
+                have_log(File2, <<"Test message 2">>),
+
+                have_no_log(SinkFile, <<"Sink test message 1">>),
+                have_log(SinkFile, <<"Sink test message 2">>),
+
+                have_log(SinkFileOld, <<"Sink test message 1">>),
+                have_no_log(SinkFileOld, <<"Sink test message 2">>),
+
+                have_log(File1Old, <<"Test message 1">>),
+                have_no_log(File1Old, <<"Test message 2">>),
+
+                have_log(File2Old, <<"Test message 1">>),
+                have_no_log(File2Old, <<"Test message 2">>)
+
+            end}]}.
+
+have_log(Data, Log) ->
+    {_,_} = binary:match(Data, Log).
+
+have_no_log(Data, Log) ->
+    nomatch = binary:match(Data, Log).
+