prosody: Add new module to load push registration for new sessions

ansible/files/prosody.cfg.lua

@@ -76,6 +76,7 @@ modules_enabled = {
 		"turncredentials";
 		"admin_shell";
 		"snikket_client_id";
+		"snikket_ios_preserve_push";
 
 	-- Spam/abuse management
 		"spam_reporting"; -- Allow users to report spam/abuse

ansible/tasks/prosody.yml

@@ -133,6 +133,7 @@
     - mod_invites_default_group
     - mod_invites_bootstrap
     - mod_snikket_client_id
+    - mod_snikket_ios_preserve_push
 
 - name: "Install lua-ossl for encrypted push notifications"
   apt:

snikket-modules/mod_snikket_ios_preserve_push/mod_snikket_ios_preserve_push.lua

@@ -0,0 +1,22 @@
+-- The Snikket iOS client does not perform a push registration ("enable") on
+-- every new connection (it connects every time the app is opened, so we want
+-- to reduce round-trips and latency). This module attempts to locate a push
+-- registration associated with the connecting client, and load it onto the
+-- session so that mod_cloud_notify can find it.
+
+local push_store = module:open_store("cloud_notify");
+
+module:hook("resource-bind", function (event)
+	local session = event.session;
+	local client_id = session.client_id;
+	if not client_id then return; end
+	local push_registrations = push_store:get(session.username);
+	for push_identifier, push_registration in pairs(push_registrations) do
+		if push_registration.client_id == client_id then
+			session.push_identifier = push_identifier;
+			session.push_settings = push_registration;
+			module:log("debug", "Restored push registration for %s (%s)", client_id, push_identifier);
+			break;
+		end
+	end
+end, 10);