Add avatar and topic settings for server notice room

changelog.d/16679.feature

@@ -0,0 +1 @@
+Add a way to set the avatar and the topic of the server notices room.

docs/server_notices.md

@@ -46,11 +46,13 @@ server_notices:
    system_mxid_display_name: "Server Notices"
    system_mxid_avatar_url: "mxc://server.com/oumMVlgDnLYFaPVkExemNVVZ"
    room_name: "Server Notices"
+   room_avatar_url: "mxc://server.com/oumMVlgDnLYFaPVkExemNVVZ"
+   room_topic: "Room used by your server admin to notice you of important information"
 ```
 
 The only compulsory setting is `system_mxid_localpart`, which defines the user
 id of the Server Notices user, as above. `room_name` defines the name of the
-room which will be created.
+room which will be created, `room_avatar_url` its avatar and `room_topic` its topic.
 
 `system_mxid_display_name` and `system_mxid_avatar_url` can be used to set the
 displayname and avatar of the Server Notices user.

docs/usage/configuration/config_documentation.md

@@ -3815,6 +3815,8 @@ Sub-options for this setting include:
 * `system_mxid_display_name`: set the display name of the "notices" user
 * `system_mxid_avatar_url`: set the avatar for the "notices" user
 * `room_name`: set the room name of the server notices room
+* `room_avatar_url`: set the room avatar URL of the server notices room
+* `room_topic`: set the room topic of the server notices room
 
 Example configuration:
 ```yaml
@@ -3823,6 +3825,8 @@ server_notices:
   system_mxid_display_name: "Server Notices"
   system_mxid_avatar_url: "mxc://server.com/oumMVlgDnLYFaPVkExemNVVZ"
   room_name: "Server Notices"
+  room_avatar_url: "mxc://server.com/oumMVlgDnLYFaPVkExemNVVZ"
+  room_topic: "Room used by your server admin to notice you of important information"
 ```
 ---
 ### `enable_room_list_search`

synapse/config/server_notices.py

@@ -38,6 +38,14 @@ class ServerNoticesConfig(Config):
         server_notices_room_name (str|None):
             The name to use for the server notices room.
             None if server notices are not enabled.
+
+        server_notices_room_avatar_url (str|None):
+            The avatar URL to use for the server notices room.
+            None if server notices are not enabled.
+
+        server_notices_room_topic (str|None):
+            The topic to use for the server notices room.
+            None if server notices are not enabled.
     """
 
     section = "servernotices"
@@ -48,6 +56,8 @@ def __init__(self, *args: Any):
         self.server_notices_mxid_display_name: Optional[str] = None
         self.server_notices_mxid_avatar_url: Optional[str] = None
         self.server_notices_room_name: Optional[str] = None
+        self.server_notices_room_avatar_url: Optional[str] = None
+        self.server_notices_room_topic: Optional[str] = None
 
     def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         c = config.get("server_notices")
@@ -62,3 +72,5 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.server_notices_mxid_avatar_url = c.get("system_mxid_avatar_url", None)
         # todo: i18n
         self.server_notices_room_name = c.get("room_name", "Server Notices")
+        self.server_notices_room_avatar_url = c.get("room_avatar_url", None)
+        self.server_notices_room_topic = c.get("room_topic", None)

synapse/server_notices/server_notices_manager.py

@@ -160,6 +160,30 @@ async def get_or_create_notice_room_for_user(self, user_id: str) -> str:
                 self._config.servernotices.server_notices_mxid_display_name,
                 self._config.servernotices.server_notices_mxid_avatar_url,
             )
+            await self._update_room_info(
+                requester,
+                room_id,
+                EventTypes.Name,
+                "name",
+                self._config.servernotices.server_notices_room_name,
+                if_changed_only=True,
+            )
+            await self._update_room_info(
+                requester,
+                room_id,
+                EventTypes.RoomAvatar,
+                "url",
+                self._config.servernotices.server_notices_room_avatar_url,
+                if_changed_only=True,
+            )
+            await self._update_room_info(
+                requester,
+                room_id,
+                EventTypes.Topic,
+                "topic",
+                self._config.servernotices.server_notices_room_topic,
+                if_changed_only=True,
+            )
             return room_id
 
         # apparently no existing notice room: create a new one
@@ -178,17 +202,33 @@ async def get_or_create_notice_room_for_user(self, user_id: str) -> str:
                 "avatar_url": self._config.servernotices.server_notices_mxid_avatar_url,
             }
 
+        room_config = {
+            "preset": RoomCreationPreset.PRIVATE_CHAT,
+            "power_level_content_override": {"users_default": -10},
+        }
+
+        if self._config.servernotices.server_notices_room_name:
+            room_config["name"] = self._config.servernotices.server_notices_room_name
+        if self._config.servernotices.server_notices_room_topic:
+            room_config["topic"] = self._config.servernotices.server_notices_room_topic
+
         room_id, _, _ = await self._room_creation_handler.create_room(
             requester,
-            config={
-                "preset": RoomCreationPreset.PRIVATE_CHAT,
-                "name": self._config.servernotices.server_notices_room_name,
-                "power_level_content_override": {"users_default": -10},
-            },
+            config=room_config,
             ratelimit=False,
             creator_join_profile=join_profile,
         )
 
+        # Room avatar can't be set at creation time so let's just send an event for that
+        if self._config.servernotices.server_notices_room_avatar_url:
+            await self._update_room_info(
+                requester,
+                room_id,
+                EventTypes.RoomAvatar,
+                "url",
+                self._config.servernotices.server_notices_room_avatar_url,
+            )
+
         self.maybe_get_notice_room_for_user.invalidate((user_id,))
 
         max_id = await self._account_data_handler.add_tag_to_room(
@@ -272,3 +312,51 @@ async def _update_notice_user_profile_if_changed(
                 ratelimit=False,
                 content={"displayname": display_name, "avatar_url": avatar_url},
             )
+
+    async def _update_room_info(
+        self,
+        requester: Requester,
+        room_id: str,
+        info_event_type: str,
+        info_content_key: str,
+        info_value: Optional[str],
+        if_changed_only: Optional[bool] = False,
+    ) -> None:
+        """
+        Updates a specific notice room's info if it's different from what is set.
+
+        Args:
+            requester: The user who is performing the update.
+            room_id: The ID of the server notice room
+            info_event_type: The event type holding the specific info
+            info_content_key: The key containing the specific info in the event's content
+            info_value: The expected value for the specific info
+            if_changed_only: Try to read the info first and does not send the event if it's already the same
+        """
+        if if_changed_only:
+            room_info_event = await self._message_handler.get_room_data(
+                requester,
+                room_id,
+                info_event_type,
+                "",
+            )
+
+            if room_info_event and room_info_event.get(info_content_key) == info_value:
+                return
+
+        if info_value is None:
+            info_value = ""
+
+        room_info_event_dict = {
+            "type": info_event_type,
+            "room_id": room_id,
+            "sender": requester.user.to_string(),
+            "state_key": "",
+            "content": {
+                info_content_key: info_value,
+            },
+        }
+
+        event, _ = await self._event_creation_handler.create_and_send_nonmember_event(
+            requester, room_info_event_dict, ratelimit=False
+        )