federation_exchange_link_sup_sup: revert to old id format if khepri i…

…s disabled

During an upgrade from pre 3.13.0 version with existing federation
exchange links, the mirrored supervisor preserves old child id
format. During migration to Khepri old child ids are converted to new
format anyway. So let's revert and use old child id format also on
3.13.0 if Mnesia is used. This is to avoid the need to handle
two formats at the same time.

deps/rabbitmq_federation/src/rabbit_federation_exchange_link_sup_sup.erl

@@ -40,15 +40,15 @@
       Record :: tuple().
 upgrade_record(mirrored_sup_childspec,
                #mirrored_sup_childspec{key = {?MODULE, #exchange{} = Exchange}} = Record) ->
-    Record#mirrored_sup_childspec{key = {?MODULE, id(Exchange)}};
+    Record#mirrored_sup_childspec{key = {?MODULE, id(Exchange, _KhepriEnabled = true)}};
 upgrade_record(_Table, Record) ->
     Record.
 
 -spec upgrade_key(Table, Key) -> Key when
       Table :: mnesia_to_khepri:mnesia_table(),
       Key :: any().
 upgrade_key(mirrored_sup_childspec, {?MODULE, #exchange{} = Exchange}) ->
-    {?MODULE, id(Exchange)};
+    {?MODULE, id(Exchange, _KhepriEnabled = true)};
 upgrade_key(_Table, Key) ->
     Key.
 
@@ -83,12 +83,15 @@ start_child(X) ->
 
 adjust({clear_upstream, VHost, UpstreamName}) ->
     _ = [rabbit_federation_link_sup:adjust(Pid, X, {clear_upstream, UpstreamName}) ||
-            {{_, #exchange{name = Name} = X}, Pid, _, _} <- mirrored_supervisor:which_children(?SUPERVISOR),
-            Name#resource.virtual_host == VHost],
+            {Id, Pid, _, _} <- mirrored_supervisor:which_children(?SUPERVISOR),
+            begin
+                #exchange{name = Name} = X = id_to_exchange(Id),
+                Name#resource.virtual_host == VHost
+            end],
     ok;
 adjust(Reason) ->
-    _ = [rabbit_federation_link_sup:adjust(Pid, X, Reason) ||
-            {{_, X}, Pid, _, _} <- mirrored_supervisor:which_children(?SUPERVISOR)],
+    _ = [rabbit_federation_link_sup:adjust(Pid, id_to_exchange(Id), Reason) ||
+            {Id, Pid, _, _} <- mirrored_supervisor:which_children(?SUPERVISOR)],
     ok.
 
 stop_child(X) ->
@@ -111,7 +114,20 @@ init([]) ->
 %% See comment in rabbit_federation_queue_link_sup_sup:id/1
 id(X = #exchange{policy = Policy}) ->
     X1 = rabbit_exchange:immutable(X),
-    {simple_id(X), X1#exchange{policy = Policy}}.
+    X2 = X1#exchange{policy = Policy},
+    id(X2, rabbit_khepri:is_enabled()).
+
+id(X, _KhepriEnabled = true) ->
+    {simple_id(X), X};
+id(X, _KhepriEnabled = false) ->
+    %% Old child id format before migration to Khepri
+    X.
 
 simple_id(#exchange{name = #resource{virtual_host = VHost, name = Name}}) ->
     [exchange, VHost, Name].
+
+id_to_exchange({_, #exchange{} = X}) ->
+    X;
+id_to_exchange(#exchange{} = X) ->
+    %% Old child id format before migration to Khepri
+    X.