feat: Visitors stats (#13139)

* fix: Fixes mac occupants check logic.

Now works and with missing muc_access_whitelist option.

* feat: Adds visitor stats.

* squash: Drops check for healthcheck room.

resources/prosody-plugins/mod_fmuc.lua

 
 local NICK_NS = 'http://jabber.org/protocol/nick';
 
+-- we send stats for the total number of rooms, total number of participants and total number of visitors
+local measure_rooms = module:measure("vnode-rooms", "amount");
+local measure_participants = module:measure("vnode-participants", "amount");
+local measure_visitors = module:measure("vnode-visitors", "amount");
+
 -- This is the domain of the main prosody that is federating with us;
 local fmuc_main_domain;
 
             "Private messaging is disabled on visitor nodes"));
     return true;
 end, 10);
+
+-- we calculate the stats on the configured interval (60 seconds by default)
+module:hook_global("stats-update", function ()
+    local participants_count, rooms_count, visitors_count = 0, 0, 0;
+
+    -- iterate over all rooms
+    for room in prosody.hosts[module.host].modules.muc.each_room() do
+        rooms_count = rooms_count + 1;
+        for _, o in room:each_occupant() do
+            if jid.host(o.bare_jid) == main_domain then
+                visitors_count = visitors_count + 1;
+            else
+                participants_count = participants_count + 1;
+            end
+        end
+        -- do not count jicofo
+        participants_count = participants_count - 1;
+    end
+
+    measure_rooms(rooms_count);
+    measure_visitors(visitors_count);
+    measure_participants(participants_count);
+end);
+
+

resources/prosody-plugins/mod_muc_max_occupants.lua

   end
   -- If we're a whitelisted user joining the room, don't bother checking the max
   -- occupants.
-  if whitelist and whitelist:contains(domain) or whitelist:contains(user..'@'..domain) then
+  if whitelist and (whitelist:contains(domain) or whitelist:contains(user..'@'..domain)) then
     return;
   end
 
 		-- from the count.
 		for _, occupant in room:each_occupant() do
 			user, domain, res = split_jid(occupant.bare_jid);
-			if not whitelist:contains(domain) and not whitelist:contains(user..'@'..domain) then
+			if not whitelist or (not whitelist:contains(domain) and not whitelist:contains(user..'@'..domain)) then
 				slots = slots - 1
 			end
 		end