Make modules loading in a dependent order (#1191)

src/gen_mod.erl

@@ -53,6 +53,7 @@
 -callback start(binary(), opts()) -> any().
 -callback stop(binary()) -> any().
 -callback mod_opt_type(atom()) -> fun((term()) -> term()) | [atom()].
+-callback depends(binary(), opts()) -> [{module(), hard | soft}].
 
 -export_type([opts/0]).
 -export_type([db_type/0]).
@@ -77,18 +78,49 @@ start_modules() ->
 
 get_modules_options(Host) ->
     ejabberd_config:get_option(
-	{modules, Host},
-	fun(Mods) ->
-	    lists:map(
+      {modules, Host},
+      fun(Mods) ->
+	      lists:map(
 		fun({M, A}) when is_atom(M), is_list(A) ->
-		    {M, A}
+			{M, A}
 		end, Mods)
-	end, []).
+      end, []).
+
+sort_modules(Host, ModOpts) ->
+    G = digraph:new([acyclic]),
+    lists:foreach(
+      fun({Mod, Opts}) ->
+	      digraph:add_vertex(G, Mod, Opts),
+	      Deps = try Mod:depends(Host, Opts) catch _:undef -> [] end,
+	      lists:foreach(
+		fun({DepMod, Type}) ->
+			case lists:keyfind(DepMod, 1, ModOpts) of
+			    false when Type == hard ->
+				ErrTxt = io_lib:format(
+					   "failed to load module '~s' "
+					   "because it depends on module '~s' "
+					   "which is not found in the config",
+					   [Mod, DepMod]),
+				?ERROR_MSG(ErrTxt, []),
+				digraph:del_vertex(G, Mod),
+				maybe_halt_ejabberd(ErrTxt);
+			    false when Type == soft ->
+				?WARNING_MSG("module '~s' is recommended for "
+					     "module '~s' but is not found in "
+					     "the config",
+					     [DepMod, Mod]);
+			    {DepMod, DepOpts} ->
+				digraph:add_vertex(G, DepMod, DepOpts),
+				digraph:add_edge(G, DepMod, Mod)
+			end
+		end, Deps)
+      end, ModOpts),
+    [digraph:vertex(G, V) || V <- digraph_utils:topsort(G)].
 
 -spec start_modules(binary()) -> any().
 
 start_modules(Host) ->
-    Modules = get_modules_options(Host),
+    Modules = sort_modules(Host, get_modules_options(Host)),
     lists:foreach(
 	fun({Module, Opts}) ->
 	    start_module(Host, Module, Opts)
@@ -121,16 +153,20 @@ start_module(Host, Module, Opts0) ->
 			    [Module, Host, Opts, Class, Reason,
 			     erlang:get_stacktrace()]),
 	  ?CRITICAL_MSG(ErrorText, []),
-	  case is_app_running(ejabberd) of
-	    true ->
-		erlang:raise(Class, Reason, erlang:get_stacktrace());
-	    false ->
-		?CRITICAL_MSG("ejabberd initialization was aborted "
-			      "because a module start failed.",
-			      []),
-		timer:sleep(3000),
-		erlang:halt(string:substr(lists:flatten(ErrorText), 1, 199))
-	  end
+          maybe_halt_ejabberd(ErrorText),
+	  erlang:raise(Class, Reason, erlang:get_stacktrace())
+    end.
+
+maybe_halt_ejabberd(ErrorText) ->
+    case is_app_running(ejabberd) of
+	false ->
+	    ?CRITICAL_MSG("ejabberd initialization was aborted "
+			  "because a module start failed.",
+			  []),
+	    timer:sleep(3000),
+	    erlang:halt(string:substr(lists:flatten(ErrorText), 1, 199));
+	true ->
+	    ok
     end.
 
 is_app_running(AppName) ->

src/mod_adhoc.erl

@@ -35,7 +35,7 @@
 	 process_sm_iq/3, get_local_commands/5,
 	 get_local_identity/5, get_local_features/5,
 	 get_sm_commands/5, get_sm_identity/5, get_sm_features/5,
-	 ping_item/4, ping_command/4, mod_opt_type/1]).
+	 ping_item/4, ping_command/4, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -284,6 +284,9 @@ ping_command(_Acc, _From, _To,
     end;
 ping_command(Acc, _From, _To, _Request) -> Acc.
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(report_commands_node) ->
     fun (B) when is_boolean(B) -> B end;

src/mod_admin_extra.erl

@@ -47,7 +47,7 @@
 	 srg_delete/2, srg_list/1, srg_get_info/2,
 	 srg_get_members/2, srg_user_add/4, srg_user_del/4,
 	 send_message/5, send_stanza/3, send_stanza_c2s/4, privacy_set/3,
-	 stats/1, stats/2, mod_opt_type/1, get_commands_spec/0]).
+	 stats/1, stats/2, mod_opt_type/1, get_commands_spec/0, depends/2]).
 
 
 -include("ejabberd.hrl").
@@ -66,6 +66,8 @@ start(_Host, _Opts) ->
 stop(_Host) ->
     ejabberd_commands:unregister_commands(get_commands_spec()).
 
+depends(_Host, _Opts) ->
+    [].
 
 %%%
 %%% Register commands

src/mod_announce.erl

@@ -33,7 +33,7 @@
 
 -export([start/2, init/0, stop/1, export/1, import/1,
 	 import/3, announce/3, send_motd/1, disco_identity/5,
-	 disco_features/5, disco_items/5,
+	 disco_features/5, disco_items/5, depends/2,
 	 send_announcement_to_all/3, announce_commands/4,
 	 announce_items/4, mod_opt_type/1]).
 
@@ -74,6 +74,9 @@ start(Host, Opts) ->
     register(gen_mod:get_module_proc(Host, ?PROCNAME),
 	     proc_lib:spawn(?MODULE, init, [])).
 
+depends(_Host, _Opts) ->
+    [{mod_adhoc, hard}].
+
 init() ->
     loop().
 

src/mod_blocking.erl

@@ -30,7 +30,7 @@
 -protocol({xep, 191, '1.2'}).
 
 -export([start/2, stop/1, process_iq/3,
-	 process_iq_set/4, process_iq_get/5, mod_opt_type/1]).
+	 process_iq_set/4, process_iq_get/5, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -63,6 +63,9 @@ stop(Host) ->
     gen_iq_handler:remove_iq_handler(ejabberd_sm, Host,
 				     ?NS_BLOCKING).
 
+depends(_Host, _Opts) ->
+    [{mod_privacy, hard}].
+
 process_iq(_From, _To, IQ) ->
     SubEl = IQ#iq.sub_el,
     IQ#iq{type = error, sub_el = [SubEl, ?ERR_NOT_ALLOWED]}.

src/mod_caps.erl

@@ -41,7 +41,7 @@
          import_start/2, import_stop/2]).
 
 %% gen_mod callbacks
--export([start/2, start_link/2, stop/1]).
+-export([start/2, start_link/2, stop/1, depends/2]).
 
 %% gen_server callbacks
 -export([init/1, handle_info/2, handle_call/3,
@@ -306,6 +306,9 @@ c2s_broadcast_recipients(InAcc, Host, C2SState,
     end;
 c2s_broadcast_recipients(Acc, _, _, _, _, _) -> Acc.
 
+depends(_Host, _Opts) ->
+    [].
+
 init([Host, Opts]) ->
     Mod = gen_mod:db_mod(Host, Opts, ?MODULE),
     Mod:init(Host, Opts),

src/mod_configure.erl

@@ -35,7 +35,8 @@
 	 get_local_features/5, get_local_items/5,
 	 adhoc_local_items/4, adhoc_local_commands/4,
 	 get_sm_identity/5, get_sm_features/5, get_sm_items/5,
-	 adhoc_sm_items/4, adhoc_sm_commands/4, mod_opt_type/1]).
+	 adhoc_sm_items/4, adhoc_sm_commands/4, mod_opt_type/1,
+	 depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -95,6 +96,9 @@ stop(Host) ->
     gen_iq_handler:remove_iq_handler(ejabberd_sm, Host,
 				     ?NS_COMMANDS).
 
+depends(_Host, _Opts) ->
+    [{mod_adhoc, hard}, {mod_last, soft}].
+
 %%%-----------------------------------------------------------------------
 
 -define(INFO_IDENTITY(Category, Type, Name, Lang),

src/mod_configure2.erl

@@ -32,7 +32,7 @@
 -behaviour(gen_mod).
 
 -export([start/2, stop/1, process_local_iq/3,
-	 mod_opt_type/1, opt_type/1]).
+	 mod_opt_type/1, opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -201,6 +201,9 @@ process_get(#xmlel{name = <<"last">>, attrs = Attrs}, Lang) ->
 %%    {result, };
 process_get(_, _) -> {error, ?ERR_BAD_REQUEST}.
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(_) -> [iqdisc].
 

src/mod_disco.erl

@@ -39,7 +39,7 @@
 	 get_sm_identity/5, get_sm_features/5, get_sm_items/5,
 	 get_info/5, register_feature/2, unregister_feature/2,
 	 register_extra_domain/2, unregister_extra_domain/2,
-	 transform_module_options/1, mod_opt_type/1]).
+	 transform_module_options/1, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -534,6 +534,9 @@ values_to_xml(Values) ->
 	      end,
 	      Values).
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(extra_domains) ->
     fun (Hs) -> [iolist_to_binary(H) || H <- Hs] end;
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;

src/mod_echo.erl

@@ -37,7 +37,7 @@
 
 -export([init/1, handle_call/3, handle_cast/2,
 	 handle_info/2, terminate/2, code_change/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -200,5 +200,8 @@ do_client_version(enabled, From, To) ->
     ?INFO_MSG("Information of the client: ~s~s",
 	      [ToS, Values_string2]).
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(host) -> fun iolist_to_binary/1;
 mod_opt_type(_) -> [host].

src/mod_fail2ban.erl

@@ -33,7 +33,7 @@
 
 -export([init/1, handle_call/3, handle_cast/2,
 	 handle_info/2, terminate/2, code_change/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -include_lib("stdlib/include/ms_transform.hrl").
 -include("ejabberd.hrl").
@@ -120,6 +120,9 @@ stop(Host) ->
     supervisor:terminate_child(ejabberd_sup, Proc),
     supervisor:delete_child(ejabberd_sup, Proc).
 
+depends(_Host, _Opts) ->
+    [].
+
 %%%===================================================================
 %%% gen_server callbacks
 %%%===================================================================

src/mod_http_api.erl

@@ -74,7 +74,7 @@
 
 -behaviour(gen_mod).
 
--export([start/2, stop/1, process/2, mod_opt_type/1]).
+-export([start/2, stop/1, process/2, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("jlib.hrl").
@@ -123,6 +123,9 @@ start(_Host, _Opts) ->
 stop(_Host) ->
     ok.
 
+depends(_Host, _Opts) ->
+    [].
+
 %% ----------
 %% basic auth
 %% ----------

src/mod_http_bind.erl

@@ -37,7 +37,7 @@
 
 -behaviour(gen_mod).
 
--export([start/2, stop/1, process/2, mod_opt_type/1]).
+-export([start/2, stop/1, process/2, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -109,6 +109,8 @@ mod_opt_type(max_pause) ->
     fun (I) when is_integer(I), I > 0 -> I end;
 mod_opt_type(_) -> [max_inactivity, max_pause].
 
+depends(_Host, _Opts) ->
+    [].
 
 %%%----------------------------------------------------------------------
 %%% Help Web Page

src/mod_http_fileserver.erl

@@ -46,7 +46,7 @@
 %% utility for other http modules
 -export([content_type/3]).
 
--export([reopen_log/1, mod_opt_type/1]).
+-export([reopen_log/1, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -109,6 +109,9 @@ stop(Host) ->
     supervisor:terminate_child(ejabberd_sup, Proc),
     supervisor:delete_child(ejabberd_sup, Proc).
 
+depends(_Host, _Opts) ->
+    [].
+
 %%====================================================================
 %% API
 %%====================================================================

src/mod_http_upload.erl

@@ -68,6 +68,7 @@
 -export([start_link/3,
 	 start/2,
 	 stop/1,
+	 depends/2,
 	 mod_opt_type/1]).
 
 %% gen_server callbacks.
@@ -222,6 +223,11 @@ mod_opt_type(_) ->
      dir_mode, docroot, put_url, get_url, service_url, custom_headers,
      rm_on_unregister, thumbnail].
 
+-spec depends(binary(), gen_mod:opts()) -> [{module(), hard | soft}].
+
+depends(_Host, _Opts) ->
+    [].
+
 %%--------------------------------------------------------------------
 %% gen_server callbacks.
 %%--------------------------------------------------------------------

src/mod_http_upload_quota.erl

@@ -39,6 +39,7 @@
 -export([start_link/3,
 	 start/2,
 	 stop/1,
+	 depends/2,
 	 mod_opt_type/1]).
 
 %% gen_server callbacks.
@@ -109,6 +110,11 @@ mod_opt_type(max_days) ->
 mod_opt_type(_) ->
     [access_soft_quota, access_hard_quota, max_days].
 
+-spec depends(binary(), gen_mod:opts()) -> [{module(), hard | soft}].
+
+depends(_Host, _Opts) ->
+    [].
+
 %%--------------------------------------------------------------------
 %% gen_server callbacks.
 %%--------------------------------------------------------------------

src/mod_ip_blacklist.erl

@@ -36,7 +36,7 @@
 
 -export([update_bl_c2s/0]).
 
--export([is_ip_in_c2s_blacklist/3, mod_opt_type/1]).
+-export([is_ip_in_c2s_blacklist/3, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -65,6 +65,9 @@ preinit(Parent, State) ->
       error:_ -> Parent ! {ok, Pid, true}
     end.
 
+depends(_Host, _Opts) ->
+    [].
+
 %% TODO:
 stop(_Host) -> ok.