Get rid of get_module_opt_subhost

It was used in two places:
- For ejabberd_admin, where the function was not usable from the CLI
  and would not work with dynamic domains, so it was removed.
  There is stil an utility function in mod_mucm should someone need it.
- For mod_muc, it was used to trigger the (un)register_subhost hooks,
  which are triggered by mongoose_router anyway when routes are added
  and all other modules including mod_muc_light are making use of this
  fact. mod_muc was the only exception here.

src/ejabberd_admin.erl

@@ -31,7 +31,6 @@
 -export([start/0, stop/0,
          %% Server
          status/0,
-         send_service_message_all_mucs/2,
          %% Accounts
          register/3, register/2, unregister/2,
          registered_users/1,
@@ -58,7 +57,7 @@
     get_loglevel/0, import_users/1, install_fallback_mnesia/1,
     join_cluster/1, leave_cluster/0, load_mnesia/1, mnesia_change_nodename/4,
     register/2, register/3, registered_users/1, remove_from_cluster/1,
-    restore_mnesia/1, send_service_message_all_mucs/2, set_master/1, status/0,
+    restore_mnesia/1, set_master/1, status/0,
     stop/0, unregister/2]).
 
 -include("mongoose.hrl").
@@ -279,7 +278,6 @@ do_leave_cluster() ->
             {error, {E, R}}
     end.
 
-
 -spec status() -> {'mongooseim_not_running', io_lib:chars()} | {'ok', io_lib:chars()}.
 status() ->
     {InternalStatus, ProvidedStatus} = init:get_status(),
@@ -294,18 +292,6 @@ status() ->
         end,
     {Is_running, String1 ++ String2}.
 
-
--spec send_service_message_all_mucs(Subject :: string() | binary(),
-                              AnnouncementText :: string() | binary()) -> 'ok'.
-send_service_message_all_mucs(Subject, AnnouncementText) ->
-    Message = io_lib:format("~s~n~s", [Subject, AnnouncementText]),
-    lists:foreach(
-      fun(Host) ->
-              MUCHost = gen_mod:get_module_opt_subhost(Host, mod_muc, mod_muc:default_host()),
-              mod_muc:broadcast_service_message(MUCHost, Message)
-      end,
-      ?MYHOSTS).
-
 %%%
 %%% Account management
 %%%

src/gen_mod.erl

@@ -42,7 +42,6 @@
          get_module_opt/4,
          get_module_opts/2,
          get_loaded_module_opts/2,
-         get_module_opt_subhost/3,
 
          loaded_modules/0,
          loaded_modules/1,
@@ -62,7 +61,6 @@
 -include("mongoose.hrl").
 
 -type module_feature() :: atom().
--type domain_name() :: mongooseim:domain_name().
 -type host_type() :: mongooseim:host_type().
 -type key_path() :: mongoose_config:key_path().
 -type opt_key() :: atom().
@@ -271,23 +269,12 @@ get_module_opt(HostType, Module, Opt) ->
 
 -spec get_module_opts(mongooseim:host_type(), module()) -> module_opts().
 get_module_opts(HostType, Module) ->
-    mongoose_config:get_opt([{modules, HostType}, Module], []).
+    mongoose_config:get_opt([{modules, HostType}, Module], #{}).
 
 -spec get_loaded_module_opts(mongooseim:host_type(), module()) -> module_opts().
 get_loaded_module_opts(HostType, Module) ->
     mongoose_config:get_opt([{modules, HostType}, Module]).
 
--spec get_module_opt_subhost(domain_name(),
-                             module(),
-                             mongoose_subdomain_utils:subdomain_pattern()) ->
-    domain_name().
-get_module_opt_subhost(Host, Module, Default) ->
-    %% TODO: try to get rid of this interface
-    %% note that get_module_opt/4 requires host_type(), while
-    %% mongoose_subdomain_utils:get_fqdn/2 expects domain_name()
-    Spec = get_module_opt(Host, Module, host, Default),
-    mongoose_subdomain_utils:get_fqdn(Spec, Host).
-
 -spec loaded_modules() -> [module()].
 loaded_modules() ->
     lists:usort(lists:flatmap(fun loaded_modules/1, ?ALL_HOST_TYPES)).

src/mod_muc.erl

@@ -492,7 +492,6 @@ init({HostType, Opts}) ->
                            text => <<"Only one MUC domain would work with this host type">>})
     end,
     mongoose_domain_api:register_subdomain(HostType, SubdomainPattern, PacketHandler),
-    register_for_global_distrib(HostType),
     %% Loading
     case LoadPermRoomsAtStartup of
         false ->
@@ -601,9 +600,7 @@ stop_if_hibernated_for_specified_time(Pid, Now, Timeout, {hibernated, LastHibern
 
 terminate(_Reason, #muc_state{host_type = HostType,
                               subdomain_pattern = SubdomainPattern}) ->
-    mongoose_domain_api:unregister_subdomain(HostType, SubdomainPattern),
-    unregister_for_global_distrib(HostType),
-    ok.
+    mongoose_domain_api:unregister_subdomain(HostType, SubdomainPattern).
 
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
@@ -1406,12 +1403,3 @@ make_server_host(To, #muc_state{host_type = HostType,
         {fqdn, _} ->
             HostType
     end.
-
-register_for_global_distrib(HostType) ->
-    %% Would not work for multitenancy
-    SubHost = gen_mod:get_module_opt_subhost(HostType, ?MODULE, default_host()),
-    mongoose_hooks:register_subhost(SubHost, false).
-
-unregister_for_global_distrib(HostType) ->
-    SubHost = gen_mod:get_module_opt_subhost(HostType, ?MODULE, default_host()),
-    mongoose_hooks:unregister_subhost(SubHost).