Strip last_msg from logs

6 files changed, 179 insertions, 12 deletions

diff --git a/src/couch_log/src/couch_log_config.erl b/src/couch_log/src/couch_log_config.erl
index 766d068a4..a7a469cc3 100644
--- a/src/couch_log/src/couch_log_config.erl
+++ b/src/couch_log/src/couch_log_config.erl
@@ -49,7 +49,8 @@ entries() ->
     [
         {level, "level", "info"},
         {level_int, "level", "info"},
-        {max_message_size, "max_message_size", "16000"}
+        {max_message_size, "max_message_size", "16000"},
+        {strip_last_msg, "strip_last_msg", "true"}
      ].
 
 
@@ -97,4 +98,10 @@ transform(max_message_size, SizeStr) ->
         Size -> Size
     catch _:_ ->
         16000
-    end.
\ No newline at end of file
+    end;
+
+transform(strip_last_msg, "false") ->
+    false;
+
+transform(strip_last_msg, _) ->
+    true.
\ No newline at end of file
diff --git a/src/couch_log/src/couch_log_config_dyn.erl b/src/couch_log/src/couch_log_config_dyn.erl
index f7541f61f..b39dcf2f5 100644
--- a/src/couch_log/src/couch_log_config_dyn.erl
+++ b/src/couch_log/src/couch_log_config_dyn.erl
@@ -25,4 +25,5 @@
 
 get(level) -> info;
 get(level_int) -> 2;
-get(max_message_size) -> 16000.
+get(max_message_size) -> 16000;
+get(strip_last_msg) -> true.
diff --git a/src/couch_log/src/couch_log_formatter.erl b/src/couch_log/src/couch_log_formatter.erl
index 4d81f184f..26997a8a6 100644
--- a/src/couch_log/src/couch_log_formatter.erl
+++ b/src/couch_log/src/couch_log_formatter.erl
@@ -68,7 +68,13 @@ format(Event) ->
 
 do_format({error, _GL, {Pid, "** Generic server " ++ _, Args}}) ->
     %% gen_server terminate
-    [Name, LastMsg, State, Reason | Extra] = Args,
+    [Name, LastMsg0, State, Reason | Extra] = Args,
+    LastMsg = case couch_log_config:get(strip_last_msg) of
+        true ->
+            redacted;
+        false ->
+            LastMsg0
+    end,
     MsgFmt = "gen_server ~w terminated with reason: ~s~n" ++
                 "  last msg: ~p~n     state: ~p~n    extra: ~p",
     MsgArgs = [Name, format_reason(Reason), LastMsg, State, Extra],
@@ -76,7 +82,13 @@ do_format({error, _GL, {Pid, "** Generic server " ++ _, Args}}) ->
 
 do_format({error, _GL, {Pid, "** State machine " ++ _, Args}}) ->
     %% gen_fsm terminate
-    [Name, LastMsg, StateName, State, Reason | Extra] = Args,
+    [Name, LastMsg0, StateName, State, Reason | Extra] = Args,
+    LastMsg = case couch_log_config:get(strip_last_msg) of
+        true ->
+            redacted;
+        false ->
+            LastMsg0
+    end,
     MsgFmt = "gen_fsm ~w in state ~w terminated with reason: ~s~n" ++
                 " last msg: ~p~n     state: ~p~n    extra: ~p",
     MsgArgs = [Name, StateName, format_reason(Reason), LastMsg, State, Extra],
@@ -84,7 +96,13 @@ do_format({error, _GL, {Pid, "** State machine " ++ _, Args}}) ->
 
 do_format({error, _GL, {Pid, "** gen_event handler" ++ _, Args}}) ->
     %% gen_event handler terminate
-    [ID, Name, LastMsg, State, Reason] = Args,
+    [ID, Name, LastMsg0, State, Reason] = Args,
+    LastMsg = case couch_log_config:get(strip_last_msg) of
+        true ->
+            redacted;
+        false ->
+            LastMsg0
+    end,
     MsgFmt = "gen_event ~w installed in ~w terminated with reason: ~s~n" ++
                 "  last msg: ~p~n     state: ~p",
     MsgArgs = [ID, Name, format_reason(Reason), LastMsg, State],
diff --git a/src/couch_log/src/couch_log_sup.erl b/src/couch_log/src/couch_log_sup.erl
index 6219a36e9..fc1ac7812 100644
--- a/src/couch_log/src/couch_log_sup.erl
+++ b/src/couch_log/src/couch_log_sup.erl
@@ -63,6 +63,8 @@ handle_config_change("log", Key, _, _, S) ->
             couch_log_config:reconfigure();
         "max_message_size" ->
             couch_log_config:reconfigure();
+        "strip_last_msg" ->
+            couch_log_config:reconfigure();
         _ ->
             % Someone may have changed the config for
             % the writer so we need to re-initialize.
diff --git a/src/couch_log/test/eunit/couch_log_config_test.erl b/src/couch_log/test/eunit/couch_log_config_test.erl
index c4677f37f..a4c4bcff2 100644
--- a/src/couch_log/test/eunit/couch_log_config_test.erl
+++ b/src/couch_log/test/eunit/couch_log_config_test.erl
@@ -25,7 +25,9 @@ couch_log_config_test_() ->
             fun check_level/0,
             fun check_max_message_size/0,
             fun check_bad_level/0,
-            fun check_bad_max_message_size/0
+            fun check_bad_max_message_size/0,
+            fun check_strip_last_msg/0,
+            fun check_bad_strip_last_msg/0
         ]
     }.
 
@@ -108,3 +110,36 @@ check_bad_max_message_size() ->
         couch_log_test_util:wait_for_config(),
         ?assertEqual(16000, couch_log_config:get(max_message_size))
     end).
+
+
+check_strip_last_msg() ->
+    % Default is true
+    ?assertEqual(true, couch_log_config:get(strip_last_msg)),
+
+    couch_log_test_util:with_config_listener(fun() ->
+        config:set("log", "strip_last_msg", "false"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual(false, couch_log_config:get(strip_last_msg)),
+
+        config:delete("log", "strip_last_msg"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual(true, couch_log_config:get(strip_last_msg))
+    end).
+
+check_bad_strip_last_msg() ->
+    % Default is true
+    ?assertEqual(true, couch_log_config:get(strip_last_msg)),
+
+    couch_log_test_util:with_config_listener(fun() ->
+        config:set("log", "strip_last_msg", "false"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual(false, couch_log_config:get(strip_last_msg)),
+
+        config:set("log", "strip_last_msg", "this is not a boolean"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual(true, couch_log_config:get(strip_last_msg)),
+
+        config:delete("log", "strip_last_msg"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual(true, couch_log_config:get(strip_last_msg))
+    end).
diff --git a/src/couch_log/test/eunit/couch_log_formatter_test.erl b/src/couch_log/test/eunit/couch_log_formatter_test.erl
index 795efcf29..24de346c6 100644
--- a/src/couch_log/test/eunit/couch_log_formatter_test.erl
+++ b/src/couch_log/test/eunit/couch_log_formatter_test.erl
@@ -81,7 +81,7 @@ gen_server_error_test() ->
     do_matches(do_format(Event), [
         "gen_server a_gen_server terminated",
         "with reason: some_reason",
-        "last msg: {foo,bar}",
+        "last msg: redacted",
         "state: server_state",
         "extra: \\[\\]"
     ]).
@@ -108,7 +108,7 @@ gen_server_error_with_extra_args_test() ->
     do_matches(do_format(Event), [
         "gen_server a_gen_server terminated",
         "with reason: some_reason",
-        "last msg: {foo,bar}",
+        "last msg: redacted",
         "state: server_state",
         "extra: \\[sad,args\\]"
     ]).
@@ -135,7 +135,7 @@ gen_fsm_error_test() ->
     do_matches(do_format(Event), [
         "gen_fsm a_gen_fsm in state state_name",
         "with reason: barf",
-        "last msg: {ohai,there}",
+        "last msg: redacted",
         "state: curr_state",
         "extra: \\[\\]"
     ]).
@@ -162,7 +162,7 @@ gen_fsm_error_with_extra_args_test() ->
     do_matches(do_format(Event), [
         "gen_fsm a_gen_fsm in state state_name",
         "with reason: barf",
-        "last msg: {ohai,there}",
+        "last msg: redacted",
         "state: curr_state",
         "extra: \\[sad,args\\]"
     ]).
@@ -195,7 +195,7 @@ gen_event_error_test() ->
     do_matches(do_format(Event), [
         "gen_event handler_id installed in a_gen_event",
         "reason: barf",
-        "last msg: {ohai,there}",
+        "last msg: redacted",
         "state: curr_state"
     ]).
 
@@ -850,6 +850,110 @@ coverage_test() ->
         })
     ).
 
+gen_server_error_with_last_msg_test() ->
+    Pid = self(),
+    Event = {
+        error,
+        erlang:group_leader(),
+        {
+            Pid,
+            "** Generic server and some stuff",
+            [a_gen_server, {foo, bar}, server_state, some_reason]
+        }
+    },
+    ?assertMatch(
+        #log_entry{
+            level = error,
+            pid = Pid
+        },
+        do_format(Event)
+    ),
+    with_last(fun() ->
+        do_matches(do_format(Event), [
+            "gen_server a_gen_server terminated",
+            "with reason: some_reason",
+            "last msg: {foo,bar}",
+            "state: server_state",
+            "extra: \\[\\]"
+        ])
+    end).
+
+gen_event_error_with_last_msg_test() ->
+    Pid = self(),
+    Event = {
+        error,
+        erlang:group_leader(),
+        {
+            Pid,
+            "** gen_event handler did a thing",
+            [
+                handler_id,
+                a_gen_event,
+                {ohai,there},
+                curr_state,
+                barf
+            ]
+        }
+    },
+    ?assertMatch(
+        #log_entry{
+            level = error,
+            pid = Pid
+        },
+        do_format(Event)
+    ),
+    with_last(fun() ->
+        do_matches(do_format(Event), [
+            "gen_event handler_id installed in a_gen_event",
+            "reason: barf",
+            "last msg: {ohai,there}",
+            "state: curr_state"
+        ])
+    end).
+
+
+gen_fsm_error_with_last_msg_test() ->
+    Pid = self(),
+    Event = {
+        error,
+        erlang:group_leader(),
+        {
+            Pid,
+            "** State machine did a thing",
+            [a_gen_fsm, {ohai,there}, state_name, curr_state, barf]
+        }
+    },
+    ?assertMatch(
+        #log_entry{
+            level = error,
+            pid = Pid
+        },
+        do_format(Event)
+    ),
+    with_last(fun() ->
+        do_matches(do_format(Event), [
+            "gen_fsm a_gen_fsm in state state_name",
+            "with reason: barf",
+            "last msg: {ohai,there}",
+            "state: curr_state",
+            "extra: \\[\\]"
+        ])
+    end).
+
+
+with_last(Fun) ->
+    meck:new(couch_log_config_dyn, [passthrough]),
+    try
+        meck:expect(couch_log_config_dyn, get, fun(Case) ->
+            case Case of
+                strip_last_msg -> false;
+                Case -> meck:passthrough([Case])
+            end
+        end),
+        Fun()
+    after
+        meck:unload(couch_log_config_dyn)
+    end.
 
 do_format(Event) ->
     E = couch_log_formatter:format(Event),