Make silly list configurable

6 files changed, 71 insertions, 5 deletions

diff --git a/rel/overlay/etc/default.ini b/rel/overlay/etc/default.ini
index 8ee51ffa9..25f3cca37 100644
--- a/rel/overlay/etc/default.ini
+++ b/rel/overlay/etc/default.ini
@@ -644,6 +644,9 @@ level = info
 ; Do not log last message received by terminated process
 ; strip_last_msg = true
 ;
+; List of fields to remove before logging the crash report
+; filter_fields = [pid, registered_name, error_info, messages]
+;
 ; There are four different log writers that can be configured
 ; to write log messages. The default writes to stderr of the
 ; Erlang VM which is useful for debugging/development as well
diff --git a/src/couch_log/src/couch_log_config.erl b/src/couch_log/src/couch_log_config.erl
index ab076cc69..55925c39f 100644
--- a/src/couch_log/src/couch_log_config.erl
+++ b/src/couch_log/src/couch_log_config.erl
@@ -50,7 +50,8 @@ entries() ->
         {level, "level", "info"},
         {level_int, "level", "info"},
         {max_message_size, "max_message_size", "16000"},
-        {strip_last_msg, "strip_last_msg", "true"}
+        {strip_last_msg, "strip_last_msg", "true"},
+        {filter_fields, "filter_fields", "[pid, registered_name, error_info, messages]"}
      ].
 
 
@@ -104,4 +105,23 @@ transform(strip_last_msg, "false") ->
     false;
 
 transform(strip_last_msg, _) ->
-    true.
+    true;
+
+transform(filter_fields, FieldsStr) ->
+    Default = [pid, registered_name, error_info, messages],
+    case parse_term(FieldsStr) of
+        {ok, List} when is_list(List) ->
+            case lists:all(fun erlang:is_atom/1, List) of
+                true ->
+                    List;
+                false ->
+                    Default
+            end;
+        _ ->
+            Default
+    end.
+
+
+parse_term(List) ->
+    {ok, Tokens, _} = erl_scan:string(List ++ "."),
+    erl_parse:parse_term(Tokens).
diff --git a/src/couch_log/src/couch_log_config_dyn.erl b/src/couch_log/src/couch_log_config_dyn.erl
index b39dcf2f5..1e1c927ae 100644
--- a/src/couch_log/src/couch_log_config_dyn.erl
+++ b/src/couch_log/src/couch_log_config_dyn.erl
@@ -26,4 +26,5 @@
 get(level) -> info;
 get(level_int) -> 2;
 get(max_message_size) -> 16000;
-get(strip_last_msg) -> true.
+get(strip_last_msg) -> true;
+get(filter_fields) -> [pid, registered_name, error_info, messages].
diff --git a/src/couch_log/src/couch_log_formatter.erl b/src/couch_log/src/couch_log_formatter.erl
index 26997a8a6..3553666f6 100644
--- a/src/couch_log/src/couch_log_formatter.erl
+++ b/src/couch_log/src/couch_log_formatter.erl
@@ -199,7 +199,7 @@ format_crash_report(Report, Neighbours) ->
     MsgFmt = "Process ~s with ~w neighbors ~s with reason: ~s",
     Args = [Name, length(Neighbours), Type, ReasonStr],
     Msg = io_lib:format(MsgFmt, Args),
-    case filter_silly_list(Report, [pid, registered_name, error_info]) of
+    case filter_silly_list(Report) of
         [] ->
             Msg;
         Rest ->
@@ -431,6 +431,11 @@ print_val(Val) ->
     {Str, _} = couch_log_trunc_io:print(Val, 500),
     Str.
 
+filter_silly_list(KV) ->
+    %% The complete list of fields is from here
+    %% https://github.com/erlang/otp/blob/7ca7a6c59543db8a6d26b95ae434e61a044b0800/lib/stdlib/src/proc_lib.erl#L539:L553
+    FilterFields = couch_log_config:get(filter_fields),
+    filter_silly_list(KV, FilterFields).
 
 filter_silly_list([], _) ->
     [];
diff --git a/src/couch_log/src/couch_log_sup.erl b/src/couch_log/src/couch_log_sup.erl
index fc1ac7812..6cb8d7395 100644
--- a/src/couch_log/src/couch_log_sup.erl
+++ b/src/couch_log/src/couch_log_sup.erl
@@ -65,6 +65,8 @@ handle_config_change("log", Key, _, _, S) ->
             couch_log_config:reconfigure();
         "strip_last_msg" ->
             couch_log_config:reconfigure();
+        "filter_fields" ->
+            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 b8ee2dab5..e47a52bc2 100644
--- a/src/couch_log/test/eunit/couch_log_config_test.erl
+++ b/src/couch_log/test/eunit/couch_log_config_test.erl
@@ -28,7 +28,9 @@ couch_log_config_test_() ->
             ?T(check_bad_level),
             ?T(check_bad_max_message_size),
             ?T(check_strip_last_msg),
-            ?T(check_bad_strip_last_msg)
+            ?T(check_bad_strip_last_msg),
+            ?T(check_filter_fields),
+            ?T(check_bad_filter_fields)
         ]
     }.
 
@@ -144,3 +146,36 @@ check_bad_strip_last_msg() ->
         couch_log_test_util:wait_for_config(),
         ?assertEqual(true, couch_log_config:get(strip_last_msg))
     end).
+
+
+check_filter_fields() ->
+    Default = [pid, registered_name, error_info, messages],
+    ?assertEqual(Default, couch_log_config:get(filter_fields)),
+
+    couch_log_test_util:with_config_listener(fun() ->
+        config:set("log", "filter_fields", "[foo, bar, baz]"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual([foo, bar, baz], couch_log_config:get(filter_fields)),
+
+        config:delete("log", "filter_fields"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual(Default, couch_log_config:get(filter_fields))
+    end).
+
+check_bad_filter_fields() ->
+    Default = [pid, registered_name, error_info, messages],
+    ?assertEqual(Default, couch_log_config:get(filter_fields)),
+
+    couch_log_test_util:with_config_listener(fun() ->
+        config:set("log", "filter_fields", "[foo, bar, baz]"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual([foo, bar, baz], couch_log_config:get(filter_fields)),
+
+        config:set("log", "filter_fields", "not a list of atoms"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual(Default, couch_log_config:get(filter_fields)),
+
+        config:delete("log", "filter_fields"),
+        couch_log_test_util:wait_for_config(),
+        ?assertEqual(Default, couch_log_config:get(filter_fields))
+    end).