Configure AE by policy.

2 files changed, 45 insertions, 4 deletions

diff --git a/src/rabbit_exchange.erl b/src/rabbit_exchange.erl
index 49952a4d70..bdb0f5db48 100644
--- a/src/rabbit_exchange.erl
+++ b/src/rabbit_exchange.erl
@@ -347,11 +347,12 @@ route1(Delivery, Decorators,
            lists:foldl(fun process_route/2, {WorkList, SeenXs, QNames},
                        AlternateDests ++ DecorateDests  ++ ExchangeDests)).
 
-process_alternate(#exchange{arguments = []}, _Results) -> %% optimisation
-    [];
-process_alternate(#exchange{name = XName, arguments = Args}, []) ->
+process_alternate(X = #exchange{name = XName, arguments = Args}, []) ->
     case rabbit_misc:r_arg(XName, exchange, Args, <<"alternate-exchange">>) of
-        undefined -> [];
+        undefined -> case rabbit_policy:get(<<"alternate-exchange">>, X) of
+                         {ok, AName} -> [rabbit_misc:r(XName, exchange, AName)];
+                         {error, _}  -> []
+                     end;
         AName     -> [AName]
     end;
 process_alternate(_X, _Results) ->
diff --git a/src/rabbit_policies.erl b/src/rabbit_policies.erl
new file mode 100644
index 0000000000..20f461bcb2
--- /dev/null
+++ b/src/rabbit_policies.erl
@@ -0,0 +1,40 @@
+%% 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 http://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) 2007-2013 GoPivotal, Inc.  All rights reserved.
+%%
+
+-module(rabbit_policies).
+-behaviour(rabbit_policy_validator).
+
+-include("rabbit.hrl").
+
+-export([register/0, validate_policy/1]).
+
+-rabbit_boot_step({?MODULE,
+                   [{description, "internal policies"},
+                    {mfa, {rabbit_policies, register, []}},
+                    {requires, rabbit_registry},
+                    {enables, recovery}]}).
+
+register() ->
+    [rabbit_registry:register(Class, Name, ?MODULE) ||
+        {Class, Name} <- [{policy_validator,  <<"alternate-exchange">>}]],
+    ok.
+
+validate_policy([{<<"alternate-exchange">>, Value}])
+  when is_binary(Value) ->
+    ok;
+validate_policy([{<<"alternate-exchange">>, Value}]) ->
+    {error, "~p is not a valid alternate exchange name", [Value]}.
+