Move log management tests into their own suite

2 files changed, 415 insertions, 298 deletions

diff --git a/test/unit_inbroker_non_parallel_SUITE.erl b/test/unit_inbroker_non_parallel_SUITE.erl
index 514031b97d..ae340aba71 100644
--- a/test/unit_inbroker_non_parallel_SUITE.erl
+++ b/test/unit_inbroker_non_parallel_SUITE.erl
@@ -40,9 +40,6 @@ groups() ->
           disk_monitor_enable,
           file_handle_cache, %% Change FHC limit.
           head_message_timestamp_statistics, %% Expect specific statistics.
-          log_management, %% Check log files.
-          log_file_initialised_during_startup,
-          log_file_fails_to_initialise_during_startup,
           externally_rotated_logs_are_automatically_reopened, %% Check log files.
           exchange_count,
           queue_count,
@@ -342,301 +339,6 @@ file_handle_cache_reserve_monitor1(_Config) ->
     ?assertEqual([{files_reserved, 0}], file_handle_cache:info([files_reserved])),
     passed.
 
-%% -------------------------------------------------------------------
-%% Log management.
-%% -------------------------------------------------------------------
-
-log_management(Config) ->
-    passed = rabbit_ct_broker_helpers:rpc(Config, 0,
-      ?MODULE, log_management1, [Config]).
-
-log_management1(_Config) ->
-    [LogFile|_] = rabbit:log_locations(),
-    Suffix = ".0",
-
-    ok = test_logs_working([LogFile]),
-
-    %% prepare basic logs
-    file:delete(LogFile ++ Suffix),
-    ok = test_logs_working([LogFile]),
-
-    %% simple log rotation
-    ok = rabbit:rotate_logs(),
-    %% FIXME: rabbit:rotate_logs/0 is asynchronous due to a limitation
-    %% in Lager. Therefore, we have no choice but to wait an arbitrary
-    %% amount of time.
-    timer:sleep(2000),
-    [true, true] = non_empty_files([LogFile ++ Suffix, LogFile]),
-    ok = test_logs_working([LogFile]),
-
-    %% log rotation on empty files
-    ok = clean_logs([LogFile], Suffix),
-    ok = rabbit:rotate_logs(),
-    timer:sleep(2000),
-    ?assertEqual([true, true], non_empty_files([LogFile ++ Suffix, LogFile])),
-
-    %% logs with suffix are not writable
-    ok = rabbit:rotate_logs(),
-    timer:sleep(2000),
-    ok = make_files_non_writable([LogFile ++ Suffix]),
-    ok = rabbit:rotate_logs(),
-    timer:sleep(2000),
-    ok = test_logs_working([LogFile]),
-
-    %% rotate when original log files are not writable
-    ok = make_files_non_writable([LogFile]),
-    ok = rabbit:rotate_logs(),
-    timer:sleep(2000),
-
-    %% logging directed to tty (first, remove handlers)
-    ok = rabbit:stop(),
-    ok = make_files_writable([LogFile ++ Suffix]),
-    ok = clean_logs([LogFile], Suffix),
-    ok = application:set_env(rabbit, lager_default_file, tty),
-    application:unset_env(rabbit, log),
-    application:unset_env(lager, handlers),
-    application:unset_env(lager, extra_sinks),
-    ok = rabbit:start(),
-    timer:sleep(200),
-    rabbit_log:info("test info"),
-
-    %% rotate logs when logging is turned off
-    ok = rabbit:stop(),
-    ok = clean_logs([LogFile], Suffix),
-    ok = application:set_env(rabbit, lager_default_file, false),
-    application:unset_env(rabbit, log),
-    application:unset_env(lager, handlers),
-    application:unset_env(lager, extra_sinks),
-    ok = rabbit:start(),
-    timer:sleep(200),
-    rabbit_log:error("test error"),
-    timer:sleep(200),
-    ?assertEqual([{error,enoent}], empty_files([LogFile])),
-
-    %% cleanup
-    ok = rabbit:stop(),
-    ok = clean_logs([LogFile], Suffix),
-    ok = application:set_env(rabbit, lager_default_file, LogFile),
-    application:unset_env(rabbit, log),
-    application:unset_env(lager, handlers),
-    application:unset_env(lager, extra_sinks),
-    ok = rabbit:start(),
-    ok = test_logs_working([LogFile]),
-    passed.
-
-log_file_initialised_during_startup(Config) ->
-    passed = rabbit_ct_broker_helpers:rpc(Config, 0,
-      ?MODULE, log_file_initialised_during_startup1, [Config]).
-
-log_file_initialised_during_startup1(_Config) ->
-    [LogFile|_] = rabbit:log_locations(),
-    Suffix = ".0",
-
-    %% start application with simple tty logging
-    ok = rabbit:stop(),
-    ok = clean_logs([LogFile], Suffix),
-    ok = application:set_env(rabbit, lager_default_file, tty),
-    application:unset_env(rabbit, log),
-    application:unset_env(lager, handlers),
-    application:unset_env(lager, extra_sinks),
-    ok = rabbit:start(),
-
-    %% start application with logging to non-existing directory
-    NonExistent = "/tmp/non-existent/test.log",
-    delete_file(NonExistent),
-    delete_file(filename:dirname(NonExistent)),
-    ok = rabbit:stop(),
-    ok = application:set_env(rabbit, lager_default_file, NonExistent),
-    application:unset_env(rabbit, log),
-    application:unset_env(lager, handlers),
-    application:unset_env(lager, extra_sinks),
-    ok = rabbit:start(),
-
-    %% clean up
-    ok = application:set_env(rabbit, lager_default_file, LogFile),
-    application:unset_env(rabbit, log),
-    application:unset_env(lager, handlers),
-    application:unset_env(lager, extra_sinks),
-    ok = rabbit:start(),
-    passed.
-
-
-log_file_fails_to_initialise_during_startup(Config) ->
-    NonWritableDir = case os:type() of
-                         {win32, _} -> "C:/Windows";
-                         _          -> "/"
-                     end,
-    case file:open(filename:join(NonWritableDir, "test.log"), [write]) of
-        {error, eacces} ->
-            passed = rabbit_ct_broker_helpers:rpc(
-                       Config, 0,
-                       ?MODULE, log_file_fails_to_initialise_during_startup1,
-                       [Config, NonWritableDir]);
-        {ok, Fd} ->
-            %% If the supposedly non-writable directory is writable
-            %% (e.g. we are running the testsuite on Windows as
-            %% Administrator), we skip this test.
-            file:close(Fd),
-            {skip, "Supposedly non-writable directory is writable"}
-    end.
-
-log_file_fails_to_initialise_during_startup1(_Config, NonWritableDir) ->
-    [LogFile|_] = rabbit:log_locations(),
-
-    %% start application with logging to directory with no
-    %% write permissions
-    ok = rabbit:stop(),
-
-    Run1 = fun() ->
-      NoPermission1 = filename:join(NonWritableDir, "test.log"),
-      delete_file(NoPermission1),
-      delete_file(filename:dirname(NoPermission1)),
-      ok = rabbit:stop(),
-      ok = application:set_env(rabbit, lager_default_file, NoPermission1),
-      application:unset_env(rabbit, log),
-      application:unset_env(lager, handlers),
-      application:unset_env(lager, extra_sinks),
-      rabbit:start()
-    end,
-
-    ok = try Run1() of
-        ok -> exit({got_success_but_expected_failure,
-                    log_rotation_no_write_permission_dir_test})
-    catch
-        throw:{error, {rabbit, {{cannot_log_to_file, _, _}, _}}} -> ok
-    end,
-
-    %% start application with logging to a subdirectory which
-    %% parent directory has no write permissions
-    NoPermission2 = filename:join([NonWritableDir,
-                                   "non-existent",
-                                   "test.log"]),
-
-    Run2 = fun() ->
-      delete_file(NoPermission2),
-      delete_file(filename:dirname(NoPermission2)),
-      case rabbit:stop() of
-          ok                         -> ok;
-          {error, lager_not_running} -> ok
-      end,
-      ok = application:set_env(rabbit, lager_default_file, NoPermission2),
-      application:unset_env(rabbit, log),
-      application:unset_env(lager, handlers),
-      application:unset_env(lager, extra_sinks),
-      rabbit:start()
-    end,
-
-    ok = try Run2() of
-        ok -> exit({got_success_but_expected_failure,
-                    log_rotation_parent_dirs_test})
-    catch
-        throw:{error, {rabbit, {{cannot_log_to_file, _, _}, _}}} -> ok
-    end,
-
-    %% clean up
-    ok = application:set_env(rabbit, lager_default_file, LogFile),
-    application:unset_env(rabbit, log),
-    application:unset_env(lager, handlers),
-    application:unset_env(lager, extra_sinks),
-    ok = rabbit:start(),
-    passed.
-
-externally_rotated_logs_are_automatically_reopened(Config) ->
-    passed = rabbit_ct_broker_helpers:rpc(Config, 0,
-      ?MODULE, externally_rotated_logs_are_automatically_reopened1, [Config]).
-
-externally_rotated_logs_are_automatically_reopened1(_Config) ->
-    [LogFile|_] = rabbit:log_locations(),
-
-    %% Make sure log file is opened
-    ok = test_logs_working([LogFile]),
-
-    %% Move it away - i.e. external log rotation happened
-    file:rename(LogFile, [LogFile, ".rotation_test"]),
-
-    %% New files should be created - test_logs_working/1 will check that
-    %% LogFile is not empty after doing some logging. And it's exactly
-    %% what we need to check here.
-    ok = test_logs_working([LogFile]),
-    passed.
-
-empty_or_nonexist_files(Files) ->
-    [case file:read_file_info(File) of
-         {ok, FInfo}     -> FInfo#file_info.size == 0;
-         {error, enoent} -> true;
-         Error           -> Error
-     end || File <- Files].
-
-empty_files(Files) ->
-    [case file:read_file_info(File) of
-         {ok, FInfo} -> FInfo#file_info.size == 0;
-         Error       -> Error
-     end || File <- Files].
-
-non_empty_files(Files) ->
-    [case EmptyFile of
-         {error, Reason} -> {error, Reason};
-         _               -> not(EmptyFile)
-     end || EmptyFile <- empty_files(Files)].
-
-test_logs_working(LogFiles) ->
-    ok = rabbit_log:error("Log a test message"),
-    %% give the error loggers some time to catch up
-    timer:sleep(1000),
-    lists:all(fun(LogFile) -> [true] =:= non_empty_files([LogFile]) end, LogFiles),
-    ok.
-
-set_permissions(Path, Mode) ->
-    case file:read_file_info(Path) of
-        {ok, FInfo} -> file:write_file_info(
-                         Path,
-                         FInfo#file_info{mode=Mode});
-        Error       -> Error
-    end.
-
-clean_logs(Files, Suffix) ->
-    [begin
-         ok = delete_file(File),
-         ok = delete_file([File, Suffix])
-     end || File <- Files],
-    ok.
-
-delete_file(File) ->
-    case file:delete(File) of
-        ok              -> ok;
-        {error, enoent} -> ok;
-        Error           -> Error
-    end.
-
-make_files_writable(Files) ->
-    [ok = file:write_file_info(File, #file_info{mode=8#644}) ||
-        File <- Files],
-    ok.
-
-make_files_non_writable(Files) ->
-    [ok = file:write_file_info(File, #file_info{mode=8#444}) ||
-        File <- Files],
-    ok.
-
-add_log_handlers(Handlers) ->
-    [ok = error_logger:add_report_handler(Handler, Args) ||
-        {Handler, Args} <- Handlers],
-    ok.
-
-%% sasl_report_file_h returns [] during terminate
-%% see: https://github.com/erlang/otp/blob/maint/lib/stdlib/src/error_logger_file_h.erl#L98
-%%
-%% error_logger_file_h returns ok since OTP 18.1
-%% see: https://github.com/erlang/otp/blob/maint/lib/stdlib/src/error_logger_file_h.erl#L98
-delete_log_handlers(Handlers) ->
-    [ok_or_empty_list(error_logger:delete_report_handler(Handler))
-     || Handler <- Handlers],
-    ok.
-
-ok_or_empty_list([]) ->
-    [];
-ok_or_empty_list(ok) ->
-    ok.
 
 %% -------------------------------------------------------------------
 %% Statistics.
diff --git a/test/unit_log_management_SUITE.erl b/test/unit_log_management_SUITE.erl
new file mode 100644
index 0000000000..8f7a069e37
--- /dev/null
+++ b/test/unit_log_management_SUITE.erl
@@ -0,0 +1,415 @@
+%% The contents of this file are subject to the Mozilla Public License
+%% Version 1.1 (the "License"); you may not use this file except in
+%% compliance with the License. You may obtain a copy of the License at
+%% https://www.mozilla.org/MPL/
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
+%% License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% The Original Code is RabbitMQ.
+%%
+%% The Initial Developer of the Original Code is GoPivotal, Inc.
+%% Copyright (c) 2011-2020 VMware, Inc. or its affiliates.  All rights reserved.
+%%
+
+-module(unit_log_management_SUITE).
+
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("common_test/include/ct.hrl").
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("kernel/include/file.hrl").
+-include_lib("amqp_client/include/amqp_client.hrl").
+
+-compile(export_all).
+
+-define(TIMEOUT, 30000).
+
+all() ->
+    [
+      {group, non_parallel_tests}
+    ].
+
+groups() ->
+    [
+      {non_parallel_tests, [], [
+          log_management, %% Check log files.
+          log_file_initialised_during_startup,
+          log_file_fails_to_initialise_during_startup,
+          externally_rotated_logs_are_automatically_reopened
+        ]}
+    ].
+
+%% -------------------------------------------------------------------
+%% Testsuite setup/teardown.
+%% -------------------------------------------------------------------
+
+init_per_suite(Config) ->
+    rabbit_ct_helpers:log_environment(),
+    rabbit_ct_helpers:run_setup_steps(Config).
+
+end_per_suite(Config) ->
+    rabbit_ct_helpers:run_teardown_steps(Config).
+
+init_per_group(Group, Config) ->
+    Config1 = rabbit_ct_helpers:set_config(Config, [
+        {rmq_nodename_suffix, Group},
+        {rmq_nodes_count, 2}
+      ]),
+    rabbit_ct_helpers:run_steps(Config1,
+      rabbit_ct_broker_helpers:setup_steps() ++
+      rabbit_ct_client_helpers:setup_steps()).
+
+end_per_group(_Group, Config) ->
+    rabbit_ct_helpers:run_steps(Config,
+      rabbit_ct_client_helpers:teardown_steps() ++
+      rabbit_ct_broker_helpers:teardown_steps()).
+
+init_per_testcase(Testcase, Config) ->
+    rabbit_ct_helpers:testcase_started(Config, Testcase).
+
+end_per_testcase(Testcase, Config) ->
+    rabbit_ct_helpers:testcase_finished(Config, Testcase).
+
+%% -------------------------------------------------------------------
+%% Application management.
+%% -------------------------------------------------------------------
+
+app_management(Config) ->
+    passed = rabbit_ct_broker_helpers:rpc(Config, 0,
+      ?MODULE, app_management1, [Config]).
+
+app_management1(_Config) ->
+    wait_for_application(rabbit),
+    %% Starting, stopping and diagnostics.  Note that we don't try
+    %% 'report' when the rabbit app is stopped and that we enable
+    %% tracing for the duration of this function.
+    ok = rabbit_trace:start(<<"/">>),
+    ok = rabbit:stop(),
+    ok = rabbit:stop(),
+    ok = no_exceptions(rabbit, status, []),
+    ok = no_exceptions(rabbit, environment, []),
+    ok = rabbit:start(),
+    ok = rabbit:start(),
+    ok = no_exceptions(rabbit, status, []),
+    ok = no_exceptions(rabbit, environment, []),
+    ok = rabbit_trace:stop(<<"/">>),
+    passed.
+
+no_exceptions(Mod, Fun, Args) ->
+    try erlang:apply(Mod, Fun, Args) of _ -> ok
+    catch Type:Ex -> {Type, Ex}
+    end.
+
+wait_for_application(Application) ->
+    wait_for_application(Application, 5000).
+
+wait_for_application(_, Time) when Time =< 0 ->
+    {error, timeout};
+wait_for_application(Application, Time) ->
+    Interval = 100,
+    case lists:keyfind(Application, 1, application:which_applications()) of
+        false ->
+            timer:sleep(Interval),
+            wait_for_application(Application, Time - Interval);
+        _ -> ok
+    end.
+
+
+
+%% -------------------------------------------------------------------
+%% Log management.
+%% -------------------------------------------------------------------
+
+log_management(Config) ->
+    passed = rabbit_ct_broker_helpers:rpc(Config, 0,
+      ?MODULE, log_management1, [Config]).
+
+log_management1(_Config) ->
+    [LogFile|_] = rabbit:log_locations(),
+    Suffix = ".0",
+
+    ok = test_logs_working([LogFile]),
+
+    %% prepare basic logs
+    file:delete(LogFile ++ Suffix),
+    ok = test_logs_working([LogFile]),
+
+    %% simple log rotation
+    ok = rabbit:rotate_logs(),
+    %% FIXME: rabbit:rotate_logs/0 is asynchronous due to a limitation
+    %% in Lager. Therefore, we have no choice but to wait an arbitrary
+    %% amount of time.
+    timer:sleep(2000),
+    [true, true] = non_empty_files([LogFile ++ Suffix, LogFile]),
+    ok = test_logs_working([LogFile]),
+
+    %% log rotation on empty files
+    ok = clean_logs([LogFile], Suffix),
+    ok = rabbit:rotate_logs(),
+    timer:sleep(2000),
+    ?assertEqual([true, true], non_empty_files([LogFile ++ Suffix, LogFile])),
+
+    %% logs with suffix are not writable
+    ok = rabbit:rotate_logs(),
+    timer:sleep(2000),
+    ok = make_files_non_writable([LogFile ++ Suffix]),
+    ok = rabbit:rotate_logs(),
+    timer:sleep(2000),
+    ok = test_logs_working([LogFile]),
+
+    %% rotate when original log files are not writable
+    ok = make_files_non_writable([LogFile]),
+    ok = rabbit:rotate_logs(),
+    timer:sleep(2000),
+
+    %% logging directed to tty (first, remove handlers)
+    ok = rabbit:stop(),
+    ok = make_files_writable([LogFile ++ Suffix]),
+    ok = clean_logs([LogFile], Suffix),
+    ok = application:set_env(rabbit, lager_default_file, tty),
+    application:unset_env(rabbit, log),
+    application:unset_env(lager, handlers),
+    application:unset_env(lager, extra_sinks),
+    ok = rabbit:start(),
+    timer:sleep(200),
+    rabbit_log:info("test info"),
+
+    %% rotate logs when logging is turned off
+    ok = rabbit:stop(),
+    ok = clean_logs([LogFile], Suffix),
+    ok = application:set_env(rabbit, lager_default_file, false),
+    application:unset_env(rabbit, log),
+    application:unset_env(lager, handlers),
+    application:unset_env(lager, extra_sinks),
+    ok = rabbit:start(),
+    timer:sleep(200),
+    rabbit_log:error("test error"),
+    timer:sleep(200),
+    ?assertEqual([{error,enoent}], empty_files([LogFile])),
+
+    %% cleanup
+    ok = rabbit:stop(),
+    ok = clean_logs([LogFile], Suffix),
+    ok = application:set_env(rabbit, lager_default_file, LogFile),
+    application:unset_env(rabbit, log),
+    application:unset_env(lager, handlers),
+    application:unset_env(lager, extra_sinks),
+    ok = rabbit:start(),
+    ok = test_logs_working([LogFile]),
+    passed.
+
+log_file_initialised_during_startup(Config) ->
+    passed = rabbit_ct_broker_helpers:rpc(Config, 0,
+      ?MODULE, log_file_initialised_during_startup1, [Config]).
+
+log_file_initialised_during_startup1(_Config) ->
+    [LogFile|_] = rabbit:log_locations(),
+    Suffix = ".0",
+
+    %% start application with simple tty logging
+    ok = rabbit:stop(),
+    ok = clean_logs([LogFile], Suffix),
+    ok = application:set_env(rabbit, lager_default_file, tty),
+    application:unset_env(rabbit, log),
+    application:unset_env(lager, handlers),
+    application:unset_env(lager, extra_sinks),
+    ok = rabbit:start(),
+
+    %% start application with logging to non-existing directory
+    NonExistent = "/tmp/non-existent/test.log",
+    delete_file(NonExistent),
+    delete_file(filename:dirname(NonExistent)),
+    ok = rabbit:stop(),
+    ok = application:set_env(rabbit, lager_default_file, NonExistent),
+    application:unset_env(rabbit, log),
+    application:unset_env(lager, handlers),
+    application:unset_env(lager, extra_sinks),
+    ok = rabbit:start(),
+
+    %% clean up
+    ok = application:set_env(rabbit, lager_default_file, LogFile),
+    application:unset_env(rabbit, log),
+    application:unset_env(lager, handlers),
+    application:unset_env(lager, extra_sinks),
+    ok = rabbit:start(),
+    passed.
+
+
+log_file_fails_to_initialise_during_startup(Config) ->
+    NonWritableDir = case os:type() of
+                         {win32, _} -> "C:/Windows";
+                         _          -> "/"
+                     end,
+    case file:open(filename:join(NonWritableDir, "test.log"), [write]) of
+        {error, eacces} ->
+            passed = rabbit_ct_broker_helpers:rpc(
+                       Config, 0,
+                       ?MODULE, log_file_fails_to_initialise_during_startup1,
+                       [Config, NonWritableDir]);
+        {ok, Fd} ->
+            %% If the supposedly non-writable directory is writable
+            %% (e.g. we are running the testsuite on Windows as
+            %% Administrator), we skip this test.
+            file:close(Fd),
+            {skip, "Supposedly non-writable directory is writable"}
+    end.
+
+log_file_fails_to_initialise_during_startup1(_Config, NonWritableDir) ->
+    [LogFile|_] = rabbit:log_locations(),
+
+    %% start application with logging to directory with no
+    %% write permissions
+    ok = rabbit:stop(),
+
+    Run1 = fun() ->
+      NoPermission1 = filename:join(NonWritableDir, "test.log"),
+      delete_file(NoPermission1),
+      delete_file(filename:dirname(NoPermission1)),
+      ok = rabbit:stop(),
+      ok = application:set_env(rabbit, lager_default_file, NoPermission1),
+      application:unset_env(rabbit, log),
+      application:unset_env(lager, handlers),
+      application:unset_env(lager, extra_sinks),
+      rabbit:start()
+    end,
+
+    ok = try Run1() of
+        ok -> exit({got_success_but_expected_failure,
+                    log_rotation_no_write_permission_dir_test})
+    catch
+        throw:{error, {rabbit, {{cannot_log_to_file, _, _}, _}}} -> ok
+    end,
+
+    %% start application with logging to a subdirectory which
+    %% parent directory has no write permissions
+    NoPermission2 = filename:join([NonWritableDir,
+                                   "non-existent",
+                                   "test.log"]),
+
+    Run2 = fun() ->
+      delete_file(NoPermission2),
+      delete_file(filename:dirname(NoPermission2)),
+      case rabbit:stop() of
+          ok                         -> ok;
+          {error, lager_not_running} -> ok
+      end,
+      ok = application:set_env(rabbit, lager_default_file, NoPermission2),
+      application:unset_env(rabbit, log),
+      application:unset_env(lager, handlers),
+      application:unset_env(lager, extra_sinks),
+      rabbit:start()
+    end,
+
+    ok = try Run2() of
+        ok -> exit({got_success_but_expected_failure,
+                    log_rotation_parent_dirs_test})
+    catch
+        throw:{error, {rabbit, {{cannot_log_to_file, _, _}, _}}} -> ok
+    end,
+
+    %% clean up
+    ok = application:set_env(rabbit, lager_default_file, LogFile),
+    application:unset_env(rabbit, log),
+    application:unset_env(lager, handlers),
+    application:unset_env(lager, extra_sinks),
+    ok = rabbit:start(),
+    passed.
+
+externally_rotated_logs_are_automatically_reopened(Config) ->
+    passed = rabbit_ct_broker_helpers:rpc(Config, 0,
+      ?MODULE, externally_rotated_logs_are_automatically_reopened1, [Config]).
+
+externally_rotated_logs_are_automatically_reopened1(_Config) ->
+    [LogFile|_] = rabbit:log_locations(),
+
+    %% Make sure log file is opened
+    ok = test_logs_working([LogFile]),
+
+    %% Move it away - i.e. external log rotation happened
+    file:rename(LogFile, [LogFile, ".rotation_test"]),
+
+    %% New files should be created - test_logs_working/1 will check that
+    %% LogFile is not empty after doing some logging. And it's exactly
+    %% what we need to check here.
+    ok = test_logs_working([LogFile]),
+    passed.
+
+empty_or_nonexist_files(Files) ->
+    [case file:read_file_info(File) of
+         {ok, FInfo}     -> FInfo#file_info.size == 0;
+         {error, enoent} -> true;
+         Error           -> Error
+     end || File <- Files].
+
+empty_files(Files) ->
+    [case file:read_file_info(File) of
+         {ok, FInfo} -> FInfo#file_info.size == 0;
+         Error       -> Error
+     end || File <- Files].
+
+non_empty_files(Files) ->
+    [case EmptyFile of
+         {error, Reason} -> {error, Reason};
+         _               -> not(EmptyFile)
+     end || EmptyFile <- empty_files(Files)].
+
+test_logs_working(LogFiles) ->
+    ok = rabbit_log:error("Log a test message"),
+    %% give the error loggers some time to catch up
+    timer:sleep(1000),
+    lists:all(fun(LogFile) -> [true] =:= non_empty_files([LogFile]) end, LogFiles),
+    ok.
+
+set_permissions(Path, Mode) ->
+    case file:read_file_info(Path) of
+        {ok, FInfo} -> file:write_file_info(
+                         Path,
+                         FInfo#file_info{mode=Mode});
+        Error       -> Error
+    end.
+
+clean_logs(Files, Suffix) ->
+    [begin
+         ok = delete_file(File),
+         ok = delete_file([File, Suffix])
+     end || File <- Files],
+    ok.
+
+delete_file(File) ->
+    case file:delete(File) of
+        ok              -> ok;
+        {error, enoent} -> ok;
+        Error           -> Error
+    end.
+
+make_files_writable(Files) ->
+    [ok = file:write_file_info(File, #file_info{mode=8#644}) ||
+        File <- Files],
+    ok.
+
+make_files_non_writable(Files) ->
+    [ok = file:write_file_info(File, #file_info{mode=8#444}) ||
+        File <- Files],
+    ok.
+
+add_log_handlers(Handlers) ->
+    [ok = error_logger:add_report_handler(Handler, Args) ||
+        {Handler, Args} <- Handlers],
+    ok.
+
+%% sasl_report_file_h returns [] during terminate
+%% see: https://github.com/erlang/otp/blob/maint/lib/stdlib/src/error_logger_file_h.erl#L98
+%%
+%% error_logger_file_h returns ok since OTP 18.1
+%% see: https://github.com/erlang/otp/blob/maint/lib/stdlib/src/error_logger_file_h.erl#L98
+delete_log_handlers(Handlers) ->
+    [ok_or_empty_list(error_logger:delete_report_handler(Handler))
+     || Handler <- Handlers],
+    ok.
+
+ok_or_empty_list([]) ->
+    [];
+ok_or_empty_list(ok) ->
+    ok.