Make the file backend clean up on terminate

src/lager.erl

@@ -33,7 +33,8 @@ start_link() ->
     %application:start(riak_err),
     Handlers = case application:get_env(lager, handlers) of
         undefined ->
-            [{lager_console_backend, [info]}];
+            [{lager_console_backend, [info]},
+                {lager_file_backend, [{"error.log", error}, {"console.log", info}]}];
         Val ->
             Val
     end,
@@ -91,6 +92,7 @@ handle_info(Info, State) ->
     {noreply, State}.
 
 terminate(_Reason, _State) ->
+    gen_event:stop(lager_event),
     ok.
 
 code_change(_OldVsn, State, _Extra) ->

src/lager_file_backend.erl

@@ -67,8 +67,13 @@ handle_event(_Event, State) ->
 handle_info(_Info, State) ->
     {ok, State}.
 
-terminate(_Reason, _State) ->
-    ok.
+terminate(_Reason, State) ->
+    io:format("lager file handler exiting~n"),
+    %% flush and close any file handles
+    lists:foreach(
+        fun({_, _, FD, _}) -> file:datasync(FD), file:close(FD);
+            (_) -> ok
+        end, State#state.files).
 
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.