Switch to hard coding the exchange name.

5 files changed, 50 insertions, 29 deletions

diff --git a/ebin/rabbit_app.in b/ebin/rabbit_app.in
index 7972ba86..7dabb8c3 100644
--- a/ebin/rabbit_app.in
+++ b/ebin/rabbit_app.in
@@ -36,7 +36,7 @@
          {auth_mechanisms, ['PLAIN', 'AMQPLAIN']},
          {auth_backends, [rabbit_auth_backend_internal]},
          {delegate_count, 16},
-         {trace_exchanges, []},
+         {trace_vhosts, []},
          {tcp_listen_options, [binary,
                                {packet,        raw},
                                {reuseaddr,     true},
diff --git a/src/rabbit_control.erl b/src/rabbit_control.erl
index 2a9dd463..52cfac9b 100644
--- a/src/rabbit_control.erl
+++ b/src/rabbit_control.erl
@@ -282,14 +282,14 @@ action(list_consumers, Node, _Args, Opts, Inform) ->
         Other             -> Other
     end;
 
-action(start_tracing, Node, [XName], Opts, Inform) ->
+action(trace_on, Node, [], Opts, Inform) ->
     VHost = list_to_binary(proplists:get_value(?VHOST_OPT, Opts)),
-    Inform("Starting tracing", []),
-    rpc_call(Node, rabbit_trace, start, [VHost, XName]);
+    Inform("Starting tracing for vhost ~p", [VHost]),
+    rpc_call(Node, rabbit_trace, start, [VHost]);
 
-action(stop_tracing, Node, [], Opts, Inform) ->
+action(trace_off, Node, [], Opts, Inform) ->
     VHost = list_to_binary(proplists:get_value(?VHOST_OPT, Opts)),
-    Inform("Stopping tracing", []),
+    Inform("Stopping tracing for vhost ~p", [VHost]),
     rpc_call(Node, rabbit_trace, stop, [VHost]);
 
 action(set_permissions, Node, [Username, CPerm, WPerm, RPerm], Opts, Inform) ->
diff --git a/src/rabbit_trace.erl b/src/rabbit_trace.erl
index cf8ee64c..1f9fe932 100644
--- a/src/rabbit_trace.erl
+++ b/src/rabbit_trace.erl
@@ -16,12 +16,13 @@
 
 -module(rabbit_trace).
 
--export([init/1, tap_trace_in/2, tap_trace_out/2, start/2, stop/1]).
+-export([init/1, tap_trace_in/2, tap_trace_out/2, start/1, stop/1]).
 
 -include("rabbit.hrl").
 -include("rabbit_framing.hrl").
 
--define(TRACE_EXCHANGES, trace_exchanges).
+-define(TRACE_VHOSTS, trace_vhosts).
+-define(XNAME, <<"amq.rabbitmq.trace">>).
 
 %%----------------------------------------------------------------------------
 
@@ -33,7 +34,7 @@
 -spec(tap_trace_in/2 :: (rabbit_types:basic_message(), state()) -> 'ok').
 -spec(tap_trace_out/2 :: (rabbit_amqqueue:qmsg(), state()) -> 'ok').
 
--spec(start/2 :: (rabbit_types:vhost(), binary()) -> 'ok').
+-spec(start/1 :: (rabbit_types:vhost()) -> 'ok').
 -spec(stop/1 :: (rabbit_types:vhost()) -> 'ok').
 
 -endif.
@@ -41,14 +42,12 @@
 %%----------------------------------------------------------------------------
 
 init(VHost) ->
-    {ok, XNs} = application:get_env(rabbit, ?TRACE_EXCHANGES),
-    case proplists:get_value(VHost, XNs, none) of
-        none -> none;
-        Name -> case rabbit_exchange:lookup(
-                       rabbit_misc:r(VHost, exchange, Name)) of
-                    {ok, X} -> X;
-                    _       -> none
-                end
+    {ok, VHosts} = application:get_env(rabbit, ?TRACE_VHOSTS),
+    case lists:member(VHost, VHosts) of
+        false -> none;
+        true  -> {ok, X} = rabbit_exchange:lookup(
+                             rabbit_misc:r(VHost, exchange, ?XNAME)),
+                 X
     end.
 
 tap_trace_in(Msg = #basic_message{exchange_name = #resource{name = XName}},
@@ -63,16 +62,16 @@ tap_trace_out({#resource{name = QName}, _QPid, _QMsgId, Redelivered, Msg},
 
 %%----------------------------------------------------------------------------
 
-start(VHost, XN) ->
-    update_config(fun (Xs) -> orddict:store(VHost, list_to_binary(XN), Xs) end).
+start(VHost) ->
+    update_config(fun (VHosts) -> [VHost | lists:delete(VHost, VHosts)] end).
 
 stop(VHost) ->
-    update_config(fun (Xs) -> orddict:erase(VHost, Xs) end).
+    update_config(fun (VHosts) -> lists:delete(VHost, VHosts) end).
 
 update_config(Fun) ->
-    {ok, Xs0} = application:get_env(rabbit, ?TRACE_EXCHANGES),
-    Xs = Fun(orddict:from_list(Xs0)),
-    application:set_env(rabbit, ?TRACE_EXCHANGES, Xs),
+    {ok, VHosts0} = application:get_env(rabbit, ?TRACE_VHOSTS),
+    VHosts = Fun(VHosts0),
+    application:set_env(rabbit, ?TRACE_VHOSTS, VHosts),
     rabbit_channel:refresh_config_all(),
     ok.
 
diff --git a/src/rabbit_upgrade_functions.erl b/src/rabbit_upgrade_functions.erl
index 31bbb929..bead388d 100644
--- a/src/rabbit_upgrade_functions.erl
+++ b/src/rabbit_upgrade_functions.erl
@@ -28,6 +28,7 @@
 -rabbit_upgrade({topic_trie,            mnesia, []}).
 -rabbit_upgrade({semi_durable_route,    mnesia, []}).
 -rabbit_upgrade({exchange_event_serial, mnesia, []}).
+-rabbit_upgrade({trace_exchanges,       mnesia, []}).
 
 %% -------------------------------------------------------------------
 
@@ -41,6 +42,7 @@
 -spec(topic_trie/0 :: () -> 'ok').
 -spec(exchange_event_serial/0 :: () -> 'ok').
 -spec(semi_durable_route/0 :: () -> 'ok').
+-spec(trace_exchanges/0 :: () -> 'ok').
 
 -endif.
 
@@ -113,6 +115,12 @@ exchange_event_serial() ->
     create(rabbit_exchange_serial, [{record_name, exchange_serial},
                                     {attributes, [name, next]}]).
 
+trace_exchanges() ->
+    [declare_exchange(
+       rabbit_misc:r(VHost, exchange, <<"amq.rabbitmq.trace">>), topic) ||
+        VHost <- rabbit_vhost:list()],
+    ok.
+
 %%--------------------------------------------------------------------
 
 transform(TableName, Fun, FieldList) ->
@@ -129,3 +137,16 @@ transform(TableName, Fun, FieldList, NewRecordName) ->
 create(Tab, TabDef) ->
     {atomic, ok} = mnesia:create_table(Tab, TabDef),
     ok.
+
+%% Dumb replacement for rabbit_exchange:declare that does not require
+%% the exchange type registry or worker pool to be running by dint of
+%% not validating anything and assuming the exchange type does not
+%% require serialisation.
+declare_exchange(XName, Type) ->
+    X = #exchange{name        = XName,
+                  type        = Type,
+                  durable     = true,
+                  auto_delete = false,
+                  internal    = false,
+                  arguments   = []},
+    ok = mnesia:dirty_write(rabbit_durable_exchange, X).
diff --git a/src/rabbit_vhost.erl b/src/rabbit_vhost.erl
index 24c130ed..67c73cf2 100644
--- a/src/rabbit_vhost.erl
+++ b/src/rabbit_vhost.erl
@@ -51,12 +51,13 @@ add(VHostPath) ->
                      rabbit_misc:r(VHostPath, exchange, Name),
                      Type, true, false, false, []) ||
                       {Name,Type} <-
-                          [{<<"">>,            direct},
-                           {<<"amq.direct">>,  direct},
-                           {<<"amq.topic">>,   topic},
-                           {<<"amq.match">>,   headers}, %% per 0-9-1 pdf
-                           {<<"amq.headers">>, headers}, %% per 0-9-1 xml
-                           {<<"amq.fanout">>,  fanout}]],
+                          [{<<"">>,                   direct},
+                           {<<"amq.direct">>,         direct},
+                           {<<"amq.topic">>,          topic},
+                           {<<"amq.match">>,          headers}, %% per 0-9-1 pdf
+                           {<<"amq.headers">>,        headers}, %% per 0-9-1 xml
+                           {<<"amq.fanout">>,         fanout},
+                           {<<"amq.rabbitmq.trace">>, topic}]],
                   ok
           end),
     rabbit_log:info("Added vhost ~p~n", [VHostPath]),