Add custom log rotator option and hourly log rotation

README.md

@@ -521,14 +521,59 @@ Some examples:
           6:00 hr
 ```
 
+On top of the day, week and month time format from newsyslog,
+hour specification is added from PR [#420](https://github.com/erlang-lager/lager/pull/420)
+
+```
+Format of hour specification is : [Hmm]
+The range for minute specification is:
+
+  mm      minutes, range 0 ... 59
+
+Some examples:
+
+  $H00    rotate every hour at HH:00
+  $D12H30 rotate every day at 12:30
+  $W0D0H0 rotate every week on Sunday at 00:00
+```
+
 To configure the crash log rotation, the following application variables are
 used:
 * `crash_log_size`
 * `crash_log_date`
 * `crash_log_count`
+* `crash_log_rotator`
 
 See the `.app.src` file for further details.
 
+Custom Log Rotation
+-------------------
+Custom log rotator could be configured with option for `lager_file_backend`
+```erlang
+{rotator, lager_rotator_default}
+```
+
+The module should provide the following callbacks as `lager_rotator_behaviour`
+
+```erlang
+%% @doc Create a log file
+-callback(create_logfile(Name::list(), Buffer::{integer(), integer()} | any()) ->
+    {ok, {FD::file:io_device(), Inode::integer(), Size::integer()}} | {error, any()}).
+
+%% @doc Open a log file
+-callback(open_logfile(Name::list(), Buffer::{integer(), integer()} | any()) ->
+    {ok, {FD::file:io_device(), Inode::integer(), Size::integer()}} | {error, any()}).
+
+%% @doc Ensure reference to current target, could be rotated
+-callback(ensure_logfile(Name::list(), FD::file:io_device(), Inode::integer(),
+                         Buffer::{integer(), integer()} | any()) ->
+    {ok, {FD::file:io_device(), Inode::integer(), Size::integer()}} | {error, any()}).
+
+%% @doc Rotate the log file
+-callback(rotate_logfile(Name::list(), Count::integer()) ->
+    ok).
+```
+
 Syslog Support
 --------------
 Lager syslog output is provided as a separate application:

src/lager.app.src

@@ -43,6 +43,8 @@
             %% Number of rotated crash logs to keep, 0 means keep only the
             %% current one - default is 0
             {crash_log_count, 5},
+            %% Crash Log Rotator Module - default is lager_rotator_default
+            {crash_log_rotator, lager_rotator_default},
             %% Whether to redirect error_logger messages into the default lager_event sink - defaults to true
             {error_logger_redirect, true},
             %% How many messages per second to allow from error_logger before we start dropping them

src/lager_crash_log.erl

@@ -46,7 +46,7 @@
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2,
         code_change/3]).
 
--export([start_link/5, start/5]).
+-export([start_link/6, start/6]).
 
 -record(state, {
         name :: string(),
@@ -56,32 +56,34 @@
         size :: integer(),
         date :: undefined | string(),
         count :: integer(),
-        flap=false :: boolean()
+        flap=false :: boolean(),
+        rotator :: atom()
 }).
 
 %% @private
-start_link(Filename, MaxBytes, Size, Date, Count) ->
+start_link(Filename, MaxBytes, Size, Date, Count, Rotator) ->
     gen_server:start_link({local, ?MODULE}, ?MODULE, [Filename, MaxBytes,
-            Size, Date, Count], []).
+            Size, Date, Count, Rotator], []).
 
 %% @private
-start(Filename, MaxBytes, Size, Date, Count) ->
+start(Filename, MaxBytes, Size, Date, Count, Rotator) ->
     gen_server:start({local, ?MODULE}, ?MODULE, [Filename, MaxBytes, Size,
-            Date, Count], []).
+            Date, Count, Rotator], []).
 
 %% @private
-init([RelFilename, MaxBytes, Size, Date, Count]) ->
+init([RelFilename, MaxBytes, Size, Date, Count, Rotator]) ->
     Filename = lager_util:expand_path(RelFilename),
-    case lager_util:open_logfile(Filename, false) of
+    case Rotator:open_logfile(Filename, false) of
         {ok, {FD, Inode, _}} ->
             schedule_rotation(Date),
             {ok, #state{name=Filename, fd=FD, inode=Inode,
-                    fmtmaxbytes=MaxBytes, size=Size, count=Count, date=Date}};
+                    fmtmaxbytes=MaxBytes, size=Size, count=Count, date=Date,
+                    rotator=Rotator}};
         {error, Reason} ->
             ?INT_LOG(error, "Failed to open crash log file ~s with error: ~s",
                 [Filename, file:format_error(Reason)]),
             {ok, #state{name=Filename, fmtmaxbytes=MaxBytes, flap=true,
-                    size=Size, count=Count, date=Date}}
+                    size=Size, count=Count, date=Date, rotator=Rotator}}
     end.
 
 %% @private
@@ -99,8 +101,8 @@ handle_cast(_Request, State) ->
     {noreply, State}.
 
 %% @private
-handle_info(rotate, #state{name=Name, count=Count, date=Date} = State) ->
-    _ = lager_util:rotate_logfile(Name, Count),
+handle_info(rotate, #state{name=Name, count=Count, date=Date, rotator=Rotator} = State) ->
+    _ = Rotator:rotate_logfile(Name, Count),
     schedule_rotation(Date),
     {noreply, State};
 handle_info(_Info, State) ->
@@ -187,7 +189,7 @@ sasl_limited_str(crash_report, Report, FmtMaxBytes) ->
     lager_stdlib:proc_lib_format(Report, FmtMaxBytes).
 
 do_log({log, Event}, #state{name=Name, fd=FD, inode=Inode, flap=Flap,
-        fmtmaxbytes=FmtMaxBytes, size=RotSize, count=Count} = State) ->
+        fmtmaxbytes=FmtMaxBytes, size=RotSize, count=Count, rotator=Rotator} = State) ->
     %% borrowed from riak_err
     {ReportStr, Pid, MsgStr, _ErrorP} = case Event of
         {error, _GL, {Pid1, Fmt, Args}} ->
@@ -202,9 +204,9 @@ do_log({log, Event}, #state{name=Name, fd=FD, inode=Inode, flap=Flap,
     if ReportStr == ignore ->
             {ok, State};
         true ->
-            case lager_util:ensure_logfile(Name, FD, Inode, false) of
+            case Rotator:ensure_logfile(Name, FD, Inode, false) of
                 {ok, {_, _, Size}} when RotSize /= 0, Size > RotSize ->
-                    _ = lager_util:rotate_logfile(Name, Count),
+                    _ = Rotator:rotate_logfile(Name, Count),
                     handle_cast({log, Event}, State);
                 {ok, {NewFD, NewInode, _Size}} ->
                     {Date, TS} = lager_util:format_time(
@@ -268,7 +270,7 @@ filesystem_test_() ->
         fun(CrashLog) ->
             {"under normal circumstances, file should be opened",
             fun() ->
-                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0),
+                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0, lager_rotator_default),
                 _ = gen_event:which_handlers(error_logger),
                 sync_error_logger:error_msg("Test message\n"),
                 {ok, Bin} = file:read_file(CrashLog),
@@ -280,7 +282,7 @@ filesystem_test_() ->
             fun() ->
                 {ok, FInfo} = file:read_file_info(CrashLog),
                 file:write_file_info(CrashLog, FInfo#file_info{mode = 0}),
-                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0),
+                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0, lager_rotator_default),
                 ?assertEqual(1, lager_test_backend:count()),
                 {_Level, _Time, Message,_Metadata} = lager_test_backend:pop(),
                 ?assertEqual(
@@ -291,7 +293,7 @@ filesystem_test_() ->
         fun(CrashLog) ->
             {"file that becomes unavailable at runtime should trigger an error message",
             fun() ->
-                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0),
+                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0, lager_rotator_default),
                 ?assertEqual(0, lager_test_backend:count()),
                 sync_error_logger:error_msg("Test message\n"),
                 _ = gen_event:which_handlers(error_logger),
@@ -316,7 +318,7 @@ filesystem_test_() ->
                 {ok, FInfo} = file:read_file_info(CrashLog),
                 OldPerms = FInfo#file_info.mode,
                 file:write_file_info(CrashLog, FInfo#file_info{mode = 0}),
-                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0),
+                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0, lager_rotator_default),
                 ?assertEqual(1, lager_test_backend:count()),
                 {_Level, _Time, Message,_Metadata} = lager_test_backend:pop(),
                 ?assertEqual(
@@ -332,7 +334,7 @@ filesystem_test_() ->
         fun(CrashLog) ->
             {"external logfile rotation/deletion should be handled",
             fun() ->
-                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0),
+                {ok, _} = ?MODULE:start_link(CrashLog, 65535, 0, undefined, 0, lager_rotator_default),
                 ?assertEqual(0, lager_test_backend:count()),
                 sync_error_logger:error_msg("Test message~n"),
                 _ = gen_event:which_handlers(error_logger),

src/lager_file_backend.erl

@@ -53,6 +53,7 @@
 -define(DEFAULT_ROTATION_SIZE, 10485760). %% 10mb
 -define(DEFAULT_ROTATION_DATE, "$D0"). %% midnight
 -define(DEFAULT_ROTATION_COUNT, 5).
+-define(DEFAULT_ROTATION_MOD, lager_rotator_default).
 -define(DEFAULT_SYNC_LEVEL, error).
 -define(DEFAULT_SYNC_INTERVAL, 1000).
 -define(DEFAULT_SYNC_SIZE, 1024*64). %% 64kb
@@ -67,6 +68,7 @@
         size = 0 :: integer(),
         date :: undefined | string(),
         count = 10 :: integer(),
+        rotator = lager_util :: atom(),
         shaper :: lager_shaper(),
         formatter :: atom(),
         formatter_config :: any(),
@@ -79,7 +81,8 @@
 
 -type option() :: {file, string()} | {level, lager:log_level()} |
                   {size, non_neg_integer()} | {date, string()} |
-                  {count, non_neg_integer()} | {high_water_mark, non_neg_integer()} |
+                  {count, non_neg_integer()} | {rotator, atom()} |
+                  {high_water_mark, non_neg_integer()} |
                   {sync_interval, non_neg_integer()} |
                   {sync_size, non_neg_integer()} | {sync_on, lager:log_level()} |
                   {check_interval, non_neg_integer()} | {formatter, atom()} |
@@ -108,16 +111,16 @@ init(LogFileConfig) when is_list(LogFileConfig) ->
             {error, {fatal, bad_config}};
         Config ->
             %% probabably a better way to do this, but whatever
-            [RelName, Level, Date, Size, Count, HighWaterMark, Flush, SyncInterval, SyncSize, SyncOn, CheckInterval, Formatter, FormatterConfig] =
-              [proplists:get_value(Key, Config) || Key <- [file, level, date, size, count, high_water_mark, flush_queue, sync_interval, sync_size, sync_on, check_interval, formatter, formatter_config]],
+            [RelName, Level, Date, Size, Count, Rotator, HighWaterMark, Flush, SyncInterval, SyncSize, SyncOn, CheckInterval, Formatter, FormatterConfig] =
+              [proplists:get_value(Key, Config) || Key <- [file, level, date, size, count, rotator, high_water_mark, flush_queue, sync_interval, sync_size, sync_on, check_interval, formatter, formatter_config]],
             FlushThr = proplists:get_value(flush_threshold, Config, 0),
             Name = lager_util:expand_path(RelName),
             schedule_rotation(Name, Date),
             Shaper = lager_util:maybe_flush(Flush, #lager_shaper{hwm=HighWaterMark, flush_threshold = FlushThr, id=Name}),
-            State0 = #state{name=Name, level=Level, size=Size, date=Date, count=Count, shaper=Shaper, formatter=Formatter,
-                formatter_config=FormatterConfig, sync_on=SyncOn, sync_interval=SyncInterval, sync_size=SyncSize,
-                check_interval=CheckInterval},
-            State = case lager_util:open_logfile(Name, {SyncSize, SyncInterval}) of
+            State0 = #state{name=Name, level=Level, size=Size, date=Date, count=Count, rotator=Rotator,
+                shaper=Shaper, formatter=Formatter, formatter_config=FormatterConfig,
+                sync_on=SyncOn, sync_interval=SyncInterval, sync_size=SyncSize, check_interval=CheckInterval},
+            State = case Rotator:create_logfile(Name, {SyncSize, SyncInterval}) of
                 {ok, {FD, Inode, _}} ->
                     State0#state{fd=FD, inode=Inode};
                 {error, Reason} ->
@@ -184,8 +187,8 @@ handle_event(_Event, State) ->
     {ok, State}.
 
 %% @private
-handle_info({rotate, File}, #state{name=File,count=Count,date=Date} = State) ->
-    _ = lager_util:rotate_logfile(File, Count),
+handle_info({rotate, File}, #state{name=File,count=Count,date=Date,rotator=Rotator} = State) ->
+    _ = Rotator:rotate_logfile(File, Count),
     State1 = close_file(State),
     schedule_rotation(File, Date),
     {ok, State1};
@@ -229,14 +232,14 @@ config_to_id(Config) ->
 
 
 write(#state{name=Name, fd=FD, inode=Inode, flap=Flap, size=RotSize,
-        count=Count} = State, Timestamp, Level, Msg) ->
+        count=Count, rotator=Rotator} = State, Timestamp, Level, Msg) ->
     LastCheck = timer:now_diff(Timestamp, State#state.last_check) div 1000,
     case LastCheck >= State#state.check_interval orelse FD == undefined of
         true ->
             %% need to check for rotation
-            case lager_util:ensure_logfile(Name, FD, Inode, {State#state.sync_size, State#state.sync_interval}) of
+            case Rotator:ensure_logfile(Name, FD, Inode, {State#state.sync_size, State#state.sync_interval}) of
                 {ok, {_, _, Size}} when RotSize /= 0, Size > RotSize ->
-                    case lager_util:rotate_logfile(Name, Count) of
+                    case Rotator:rotate_logfile(Name, Count) of
                         ok ->
                             %% go around the loop again, we'll do another rotation check and hit the next clause of ensure_logfile
                             write(State, Timestamp, Level, Msg);
@@ -309,6 +312,7 @@ validate_logfile_proplist(List) ->
                     lists:keymerge(1, lists:sort(Res), lists:sort([
                             {level, validate_loglevel(?DEFAULT_LOG_LEVEL)}, {date, DefaultRotationDate},
                             {size, ?DEFAULT_ROTATION_SIZE}, {count, ?DEFAULT_ROTATION_COUNT},
+                            {rotator, ?DEFAULT_ROTATION_MOD},
                             {sync_on, validate_loglevel(?DEFAULT_SYNC_LEVEL)}, {sync_interval, ?DEFAULT_SYNC_INTERVAL},
                             {sync_size, ?DEFAULT_SYNC_SIZE}, {check_interval, ?DEFAULT_CHECK_INTERVAL},
                             {formatter, lager_default_formatter}, {formatter_config, []}
@@ -347,6 +351,13 @@ validate_logfile_proplist([{count, Count}|Tail], Acc) ->
         _ ->
             throw({bad_config, "Invalid rotation count", Count})
     end;
+validate_logfile_proplist([{rotator, Rotator}|Tail], Acc) ->
+    case is_atom(Rotator) of
+        true ->
+            validate_logfile_proplist(Tail, [{rotator, Rotator}|Acc]);
+        false ->
+            throw({bad_config, "Invalid rotation module", Rotator})
+    end;
 validate_logfile_proplist([{high_water_mark, HighWaterMark}|Tail], Acc) ->
     case HighWaterMark of
         Hwm when is_integer(Hwm), Hwm >= 0 ->
@@ -441,24 +452,26 @@ rotation_test_() ->
             SyncLevel = validate_loglevel(?DEFAULT_SYNC_LEVEL),
             SyncSize = ?DEFAULT_SYNC_SIZE,
             SyncInterval = ?DEFAULT_SYNC_INTERVAL,
+            Rotator = ?DEFAULT_ROTATION_MOD,
             CheckInterval = 0, %% hard to test delayed mode
             TestDir = lager_util:create_test_dir(),
             TestLog = filename:join(TestDir, "test.log"),
 
             #state{name=TestLog, level=?DEBUG, sync_on=SyncLevel,
-                sync_size=SyncSize, sync_interval=SyncInterval, check_interval=CheckInterval}
+                sync_size=SyncSize, sync_interval=SyncInterval, check_interval=CheckInterval,
+                rotator=Rotator}
 
         end,
         fun(#state{name=TestLog}) ->
             lager_util:delete_test_dir(filename:dirname(TestLog))
         end, [
-        fun(DefaultState = #state{name=TestLog, sync_size=SyncSize, sync_interval = SyncInterval}) ->
+        fun(DefaultState = #state{name=TestLog, sync_size=SyncSize, sync_interval = SyncInterval, rotator = Rotator}) ->
             {"External rotation should work",
             fun() ->
-                {ok, {FD, Inode, _}} = lager_util:open_logfile(TestLog, {SyncSize, SyncInterval}),
+                {ok, {FD, Inode, _}} = Rotator:open_logfile(TestLog, {SyncSize, SyncInterval}),
                 State0 = DefaultState#state{fd=FD, inode=Inode},
                 ?assertMatch(#state{name=TestLog, level=?DEBUG, fd=FD, inode=Inode},
-                    write(State0, os:timestamp(), ?DEBUG, "hello world")),
+                write(State0, os:timestamp(), ?DEBUG, "hello world")),
                 file:delete(TestLog),
                 Result = write(State0, os:timestamp(), ?DEBUG, "hello world"),
                 %% assert file has changed
@@ -472,15 +485,15 @@ rotation_test_() ->
                 ok
             end}
         end,
-        fun(DefaultState = #state{name=TestLog, sync_size=SyncSize, sync_interval = SyncInterval}) ->
+        fun(DefaultState = #state{name=TestLog, sync_size=SyncSize, sync_interval = SyncInterval, rotator = Rotator}) ->
             {"Internal rotation and delayed write",
             fun() ->
                 TestLog0 = TestLog ++ ".0",
                 CheckInterval = 3000, % 3 sec
                 RotationSize = 15,
                 PreviousCheck = os:timestamp(),
 
-                {ok, {FD, Inode, _}} = lager_util:open_logfile(TestLog, {SyncSize, SyncInterval}),
+                {ok, {FD, Inode, _}} = Rotator:open_logfile(TestLog, {SyncSize, SyncInterval}),
                 State0 = DefaultState#state{
                     fd=FD, inode=Inode, size=RotationSize,
                     check_interval=CheckInterval, last_check=PreviousCheck},

src/lager_rotator_behaviour.erl

@@ -0,0 +1,18 @@
+-module(lager_rotator_behaviour).
+
+%% @doc Create a log file
+-callback(create_logfile(Name::list(), Buffer::{integer(), integer()} | any()) ->
+    {ok, {file:io_device(), integer(), integer()}} | {error, any()}).
+
+%% @doc Open a log file
+-callback(open_logfile(Name::list(), Buffer::{integer(), integer()} | any()) ->
+    {ok, {file:io_device(), integer(), integer()}} | {error, any()}).
+
+%% @doc Ensure reference to current target, could be rotated
+-callback(ensure_logfile(Name::list(), FD::file:io_device(), Inode::integer(),
+                         Buffer::{integer(), integer()} | any()) ->
+    {ok, {file:io_device(), integer(), integer()}} | {error, any()}).
+
+%% @doc Rotate the log file
+-callback(rotate_logfile(Name::list(), Count::integer()) ->
+    ok).