Remove user-visible groups/communities code (#12553)

Makes it so that groups/communities no longer exist from a user-POV. E.g. we remove:

* All API endpoints (including Client-Server, Server-Server, and admin).
* Documented configuration options (and the experimental flag, which is now unused).
* Special handling during room upgrades.
* The `groups` section of the `/sync` response.

changelog.d/12553.removal

@@ -0,0 +1 @@
+Remove support for the non-standard groups/communities feature from Synapse.

docs/sample_config.yaml

@@ -2521,16 +2521,6 @@ push:
 #        "events_default": 1
 
 
-# Uncomment to allow non-server-admin users to create groups on this server
-#
-#enable_group_creation: true
-
-# If enabled, non server admins can only create groups with local parts
-# starting with this prefix
-#
-#group_creation_prefix: "unofficial_"
-
-
 
 # User Directory configuration
 #

docs/usage/configuration/config_documentation.md

@@ -3145,25 +3145,6 @@ Example configuration:
 encryption_enabled_by_default_for_room_type: invite
 ```
 ---
-Config option: `enable_group_creation`
-
-Set to true to allow non-server-admin users to create groups on this server
-
-Example configuration:
-```yaml
-enable_group_creation: true
-```
----
-Config option: `group_creation_prefix`
-
-If enabled/present, non-server admins can only create groups with local parts
-starting with this prefix.
-
-Example configuration:
-```yaml
-group_creation_prefix: "unofficial_"
-```
----
 Config option: `user_directory`
 
 This setting defines options related to the user directory. 

synapse/api/constants.py

@@ -31,11 +31,6 @@
 # the maximum length for a user id is 255 characters
 MAX_USERID_LENGTH = 255
 
-# The maximum length for a group id is 255 characters
-MAX_GROUPID_LENGTH = 255
-MAX_GROUP_CATEGORYID_LENGTH = 255
-MAX_GROUP_ROLEID_LENGTH = 255
-
 
 class Membership:
 

synapse/app/generic_worker.py

@@ -69,7 +69,6 @@
 from synapse.rest.client import (
     account_data,
     events,
-    groups,
     initial_sync,
     login,
     presence,
@@ -323,9 +322,6 @@ def _listen_http(self, listener_config: ListenerConfig) -> None:
 
                     presence.register_servlets(self, resource)
 
-                    if self.config.experimental.groups_enabled:
-                        groups.register_servlets(self, resource)
-
                     resources.update({CLIENT_API_PREFIX: resource})
 
                     resources.update(build_synapse_client_resource_tree(self))

synapse/config/experimental.py

@@ -73,9 +73,6 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         # MSC3720 (Account status endpoint)
         self.msc3720_enabled: bool = experimental.get("msc3720_enabled", False)
 
-        # The deprecated groups feature.
-        self.groups_enabled: bool = experimental.get("groups_enabled", False)
-
         # MSC2654: Unread counts
         self.msc2654_enabled: bool = experimental.get("msc2654_enabled", False)
 

synapse/config/groups.py

@@ -25,15 +25,3 @@ class GroupsConfig(Config):
     def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.enable_group_creation = config.get("enable_group_creation", False)
         self.group_creation_prefix = config.get("group_creation_prefix", "")
-
-    def generate_config_section(self, **kwargs: Any) -> str:
-        return """\
-        # Uncomment to allow non-server-admin users to create groups on this server
-        #
-        #enable_group_creation: true
-
-        # If enabled, non server admins can only create groups with local parts
-        # starting with this prefix
-        #
-        #group_creation_prefix: "unofficial_"
-        """

synapse/federation/transport/server/__init__.py

@@ -27,10 +27,6 @@
     FederationAccountStatusServlet,
     FederationTimestampLookupServlet,
 )
-from synapse.federation.transport.server.groups_local import GROUP_LOCAL_SERVLET_CLASSES
-from synapse.federation.transport.server.groups_server import (
-    GROUP_SERVER_SERVLET_CLASSES,
-)
 from synapse.http.server import HttpServer, JsonResource
 from synapse.http.servlet import (
     parse_boolean_from_args,
@@ -199,38 +195,6 @@ async def on_POST(
         return 200, data
 
 
-class FederationGroupsRenewAttestaionServlet(BaseFederationServlet):
-    """A group or user's server renews their attestation"""
-
-    PATH = "/groups/(?P<group_id>[^/]*)/renew_attestation/(?P<user_id>[^/]*)"
-
-    def __init__(
-        self,
-        hs: "HomeServer",
-        authenticator: Authenticator,
-        ratelimiter: FederationRateLimiter,
-        server_name: str,
-    ):
-        super().__init__(hs, authenticator, ratelimiter, server_name)
-        self.handler = hs.get_groups_attestation_renewer()
-
-    async def on_POST(
-        self,
-        origin: str,
-        content: JsonDict,
-        query: Dict[bytes, List[bytes]],
-        group_id: str,
-        user_id: str,
-    ) -> Tuple[int, JsonDict]:
-        # We don't need to check auth here as we check the attestation signatures
-
-        new_content = await self.handler.on_renew_attestation(
-            group_id, user_id, content
-        )
-
-        return 200, new_content
-
-
 class OpenIdUserInfo(BaseFederationServlet):
     """
     Exchange a bearer token for information about a user.
@@ -292,16 +256,9 @@ async def on_GET(
 SERVLET_GROUPS: Dict[str, Iterable[Type[BaseFederationServlet]]] = {
     "federation": FEDERATION_SERVLET_CLASSES,
     "room_list": (PublicRoomList,),
-    "group_server": GROUP_SERVER_SERVLET_CLASSES,
-    "group_local": GROUP_LOCAL_SERVLET_CLASSES,
-    "group_attestation": (FederationGroupsRenewAttestaionServlet,),
     "openid": (OpenIdUserInfo,),
 }
 
-DEFAULT_SERVLET_GROUPS = ("federation", "room_list", "openid")
-
-GROUP_SERVLET_GROUPS = ("group_server", "group_local", "group_attestation")
-
 
 def register_servlets(
     hs: "HomeServer",
@@ -324,10 +281,7 @@ def register_servlets(
             Defaults to ``DEFAULT_SERVLET_GROUPS``.
     """
     if not servlet_groups:
-        servlet_groups = DEFAULT_SERVLET_GROUPS
-        # Only allow the groups servlets if the deprecated groups feature is enabled.
-        if hs.config.experimental.groups_enabled:
-            servlet_groups = servlet_groups + GROUP_SERVLET_GROUPS
+        servlet_groups = SERVLET_GROUPS.keys()
 
     for servlet_group in servlet_groups:
         # Skip unknown servlet groups.