Store registered users in a namespaced table, deactivate upon expiry

To deactivate users, we need their `actor_user_id` (MAS-specific). I don't believe there's a way to get this from Synapse. So, we store user's detailed in a namespaced table upon registering them, along with the creation timestamp, and deactivate them once they're considered expired.

modules/restricted-guests/synapse/synapse_guest_module/guest_module.py

@@ -7,11 +7,13 @@
 # Originally licensed under the Apache License, Version 2.0:
 # <http://www.apache.org/licenses/LICENSE-2.0>.
 
+import asyncio
 import logging
 from typing import Any, Dict, Literal, Optional, Tuple, Union
 
 from synapse.module_api import (
     NOT_SPAM,
+    LoggingTransaction,
     ModuleApi,
     ProfileInfo,
     UserProfile,
@@ -33,12 +35,20 @@ class GuestModule:
     def __init__(self, config: GuestModuleConfig, api: ModuleApi):
         self._api = api
         self._config = config
+        self._mas_tables_ready: asyncio.Event | None = None
 
         mas_admin_client = (
             MasAdminClient(api, config.mas) if config.mas is not None else None
         )
+        if config.mas is not None:
+            self._mas_tables_ready = asyncio.Event()
+            run_as_background_process(
+                "guest_module_mas_db_init",
+                self._init_mas_tables,
+                bg_start_span=False,
+            )
         self.registration_servlet = GuestRegistrationServlet(
-            config, api, mas_admin_client
+            config, api, mas_admin_client, self._mas_tables_ready
         )
         self._api.register_web_resource(
             "/_synapse/client/register_guest", self.registration_servlet
@@ -54,7 +64,9 @@ class GuestModule:
         )
 
         # Start the user reaper
-        self.reaper = GuestUserReaper(api, config)
+        self.reaper = GuestUserReaper(
+            api, config, mas_admin_client, self._mas_tables_ready
+        )
         if config.enable_user_reaper:
             run_as_background_process(
                 "guest_module_reaper_bg_task",
@@ -152,6 +164,39 @@ class GuestModule:
                 )
                 await self._api.set_displayname(user_id_1, guest_display_name)
 
+    async def _init_mas_tables(self) -> None:
+        if self._mas_tables_ready is None:
+            return
+
+        try:
+            await self._api.run_db_interaction(
+                "guest_module_create_mas_tables",
+                self._create_mas_tables,
+            )
+        except Exception as err:
+            logger.error("Failed to initialize MAS tables: %s", err)
+        finally:
+            self._mas_tables_ready.set()
+
+    @staticmethod
+    def _create_mas_tables(txn: LoggingTransaction) -> None:
+        txn.execute(
+            """
+            CREATE TABLE IF NOT EXISTS guest_module_mas_users (
+                mas_user_id TEXT PRIMARY KEY,
+                created_at BIGINT NOT NULL
+            )
+            """,
+            (),
+        )
+        txn.execute(
+            """
+            CREATE INDEX IF NOT EXISTS guest_module_mas_users_created_at
+            ON guest_module_mas_users (created_at)
+            """,
+            (),
+        )
+
     async def callback_user_may_create_room(
         self,
         user_id: str,

modules/restricted-guests/synapse/synapse_guest_module/guest_registration_servlet.py

@@ -7,12 +7,15 @@
 # Originally licensed under the Apache License, Version 2.0:
 # <http://www.apache.org/licenses/LICENSE-2.0>.
 
+import asyncio
 import logging
 import secrets
 import string
+import time
 from typing import Any, Dict, Tuple
 
 from synapse.module_api import (
+    DatabasePool,
     DirectServeJsonResource,
     ModuleApi,
     parse_json_object_from_request,
@@ -38,11 +41,13 @@ class GuestRegistrationServlet(DirectServeJsonResource):
         config: GuestModuleConfig,
         api: ModuleApi,
         mas_admin_client: MasAdminClient | None = None,
+        mas_tables_ready: asyncio.Event | None = None,
     ):
         super().__init__()
         self._api = api
         self._config = config
         self._mas_admin_client = mas_admin_client
+        self._mas_tables_ready = mas_tables_ready
 
     async def _async_render_POST(self, request: Request) -> Tuple[int, Dict[str, Any]]:
         """On POST requests, generate a new username for a guest, check that it
@@ -96,6 +101,8 @@ class GuestRegistrationServlet(DirectServeJsonResource):
                     displayname + self._config.display_name_suffix,
                 )
 
+                await self._store_mas_user(mas_user_id, int(time.time()))
+
                 # Determine how long to keep the access token valid for.
                 #
                 # If a user reaper is enabled, just have the token expire after
@@ -123,3 +130,21 @@ class GuestRegistrationServlet(DirectServeJsonResource):
             return 201, res
 
         return 500, {"msg": "Internal error: Could not find a free username"}
+
+    async def _store_mas_user(self, mas_user_id: str, created_at: int) -> None:
+        if self._mas_tables_ready is not None:
+            await self._mas_tables_ready.wait()
+
+        def store_user(txn: Any) -> None:
+            DatabasePool.simple_insert_txn(
+                txn,
+                table="guest_module_mas_users",
+                values={
+                    "mas_user_id": mas_user_id,
+                    "created_at": created_at,
+                },
+            )
+
+        await self._api.run_db_interaction(
+            "guest_module_store_mas_user", store_user
+        )

modules/restricted-guests/synapse/synapse_guest_module/guest_user_reaper.py

@@ -7,6 +7,7 @@
 # Originally licensed under the Apache License, Version 2.0:
 # <http://www.apache.org/licenses/LICENSE-2.0>.
 
+import asyncio
 import logging
 import time
 from typing import List
@@ -14,14 +15,23 @@ from typing import List
 from synapse.module_api import DatabasePool, LoggingTransaction, ModuleApi
 
 from synapse_guest_module.config import GuestModuleConfig
+from synapse_guest_module.mas_admin_client import MasAdminClient
 
 logger = logging.getLogger("synapse.contrib." + __name__)
 
 
 class GuestUserReaper:
-    def __init__(self, api: ModuleApi, config: GuestModuleConfig):
+    def __init__(
+        self,
+        api: ModuleApi,
+        config: GuestModuleConfig,
+        mas_admin_client: MasAdminClient | None = None,
+        mas_tables_ready: asyncio.Event | None = None,
+    ):
         self._api = api
         self._config = config
+        self._mas_admin_client = mas_admin_client
+        self._mas_tables_ready = mas_tables_ready
         self.reaper_user = f"{config.user_id_prefix}reaper"
 
     async def run(self) -> None:
@@ -43,6 +53,9 @@ class GuestUserReaper:
         """Deactivate all users that are older than the specified expiration
         interval. This uses the admin API to disable the user.
         """
+        if self._mas_admin_client is not None:
+            await self._deactivate_expired_mas_users()
+            return
 
         def get_expired_users(txn: LoggingTransaction) -> List[str]:
             sql = """
@@ -92,6 +105,55 @@ class GuestUserReaper:
                 except Exception as e:
                     logger.error('Failed to delete user "%s": %s', user_id, e)
 
+    async def _deactivate_expired_mas_users(self) -> None:
+        if self._mas_tables_ready is not None:
+            await self._mas_tables_ready.wait()
+
+        def get_expired_users(txn: LoggingTransaction) -> List[str]:
+            expire_ts_seconds = int(time.time() - self._config.user_expiration_seconds)
+            txn.execute(
+                """
+                SELECT mas_user_id
+                FROM guest_module_mas_users
+                WHERE created_at < ?
+                """,
+                (expire_ts_seconds,),
+            )
+            expired_users_rows = txn.fetchall()
+
+            return [row[0] for row in expired_users_rows]
+
+        expired_users: List[str] = await self._api.run_db_interaction(
+            "guest_module_get_expired_mas_users",
+            get_expired_users,
+        )
+
+        if len(expired_users) == 0:
+            return
+
+        logger.info("Deactivating %d expired MAS users", len(expired_users))
+
+        token = await self._mas_admin_client.request_admin_token()
+
+        for mas_user_id in expired_users:
+            try:
+                await self._mas_admin_client.deactivate_user(mas_user_id, token)
+                await self._remove_mas_user(mas_user_id)
+            except Exception as e:
+                logger.error('Failed to deactivate MAS user "%s": %s', mas_user_id, e)
+
+    async def _remove_mas_user(self, mas_user_id: str) -> None:
+        def delete_user(txn: LoggingTransaction) -> None:
+            txn.execute(
+                "DELETE FROM guest_module_mas_users WHERE mas_user_id = ?",
+                (mas_user_id,),
+            )
+
+        await self._api.run_db_interaction(
+            "guest_module_delete_mas_user",
+            delete_user,
+        )
+
     async def get_admin_token(self) -> str:
         """Create a new admin user in synapse so the module can call the admin
         api. If no user or login session exists, we create new ones.