Add delete group admin API

changelog.d/5002.feature

@@ -0,0 +1 @@
+Add a delete group admin API.

docs/admin_api/delete_group.md

@@ -0,0 +1,14 @@
+# Delete a local group
+
+This API lets a server admin delete a local group. Doing so will kick all
+users out of the group so that their clients will correctly handle the group
+being deleted.
+
+
+The API is:
+
+```
+POST /_matrix/client/r0/admin/delete_group/<group_id>
+```
+
+including an `access_token` of a server admin.

synapse/groups/groups_server.py

@@ -22,6 +22,7 @@
 
 from synapse.api.errors import SynapseError
 from synapse.types import GroupID, RoomID, UserID, get_domain_from_id
+from synapse.util.async_helpers import concurrently_execute
 
 logger = logging.getLogger(__name__)
 
@@ -896,6 +897,78 @@ def create_group(self, group_id, requester_user_id, content):
             "group_id": group_id,
         })
 
+    @defer.inlineCallbacks
+    def delete_group(self, group_id, requester_user_id):
+        """Deletes a group, kicking out all current members.
+
+        Only group admins or server admins can call this request
+
+        Args:
+            group_id (str)
+            request_user_id (str)
+
+        Returns:
+            Deferred
+        """
+
+        yield self.check_group_is_ours(
+            group_id, requester_user_id,
+            and_exists=True,
+        )
+
+        # Only server admins or group admins can delete groups.
+
+        is_admin = yield self.store.is_user_admin_in_group(
+            group_id, requester_user_id
+        )
+
+        if not is_admin:
+            is_admin = yield self.auth.is_server_admin(
+                UserID.from_string(requester_user_id),
+            )
+
+        if not is_admin:
+            raise SynapseError(403, "User is not an admin")
+
+        # Before deleting the group lets kick everyone out of it
+        users = yield self.store.get_users_in_group(
+            group_id, include_private=True,
+        )
+
+        @defer.inlineCallbacks
+        def _kick_user_from_group(user_id):
+            if self.hs.is_mine_id(user_id):
+                groups_local = self.hs.get_groups_local_handler()
+                yield groups_local.user_removed_from_group(group_id, user_id, {})
+            else:
+                yield self.transport_client.remove_user_from_group_notification(
+                    get_domain_from_id(user_id), group_id, user_id, {}
+                )
+                yield self.store.maybe_delete_remote_profile_cache(user_id)
+
+        # We kick users out in the order of:
+        #   1. Non-admins
+        #   2. Other admins
+        #   3. The requester
+        #
+        # This is so that if the deletion fails for some reason other admins or
+        # the requester still has auth to retry.
+        non_admins = []
+        admins = []
+        for u in users:
+            if u["user_id"] == requester_user_id:
+                continue
+            if u["is_admin"]:
+                admins.append(u["user_id"])
+            else:
+                non_admins.append(u["user_id"])
+
+        yield concurrently_execute(_kick_user_from_group, non_admins, 10)
+        yield concurrently_execute(_kick_user_from_group, admins, 10)
+        yield _kick_user_from_group(requester_user_id)
+
+        yield self.store.delete_group(group_id)
+
 
 def _parse_join_policy_from_contents(content):
     """Given a content for a request, return the specified join policy or None

synapse/rest/client/v1/admin.py

@@ -784,6 +784,31 @@ def on_GET(self, request, target_user_id):
         defer.returnValue((200, ret))
 
 
+class DeleteGroupAdminRestServlet(ClientV1RestServlet):
+    """Allows deleting of local groups
+    """
+    PATTERNS = client_path_patterns("/admin/delete_group/(?P<group_id>[^/]*)")
+
+    def __init__(self, hs):
+        super(DeleteGroupAdminRestServlet, self).__init__(hs)
+        self.group_server = hs.get_groups_server_handler()
+        self.is_mine_id = hs.is_mine_id
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, group_id):
+        requester = yield self.auth.get_user_by_req(request)
+        is_admin = yield self.auth.is_server_admin(requester.user)
+
+        if not is_admin:
+            raise AuthError(403, "You are not a server admin")
+
+        if not self.is_mine_id(group_id):
+            raise SynapseError(400, "Can only delete local groups")
+
+        yield self.group_server.delete_group(group_id, requester.user.to_string())
+        defer.returnValue((200, {}))
+
+
 def register_servlets(hs, http_server):
     WhoisRestServlet(hs).register(http_server)
     PurgeMediaCacheRestServlet(hs).register(http_server)
@@ -799,3 +824,4 @@ def register_servlets(hs, http_server):
     ListMediaInRoom(hs).register(http_server)
     UserRegisterServlet(hs).register(http_server)
     VersionServlet(hs).register(http_server)
+    DeleteGroupAdminRestServlet(hs).register(http_server)

synapse/storage/group_server.py

@@ -1150,3 +1150,40 @@ def _get_all_groups_changes_txn(txn):
 
     def get_group_stream_token(self):
         return self._group_updates_id_gen.get_current_token()
+
+    def delete_group(self, group_id):
+        """Deletes a group fully from the database.
+
+        Args:
+            group_id (str)
+
+        Returns:
+            Deferred
+        """
+
+        def _delete_group_txn(txn):
+            tables = [
+                "groups",
+                "group_users",
+                "group_invites",
+                "group_rooms",
+                "group_summary_rooms",
+                "group_summary_room_categories",
+                "group_room_categories",
+                "group_summary_users",
+                "group_summary_roles",
+                "group_roles",
+                "group_attestations_renewals",
+                "group_attestations_remote",
+            ]
+
+            for table in tables:
+                self._simple_delete_txn(
+                    txn,
+                    table=table,
+                    keyvalues={"group_id": group_id},
+                )
+
+        return self.runInteraction(
+            "delete_group", _delete_group_txn
+        )

tests/rest/client/v1/test_admin.py

@@ -21,6 +21,7 @@
 
 from synapse.api.constants import UserTypes
 from synapse.rest.client.v1 import admin, events, login, room
+from synapse.rest.client.v2_alpha import groups
 
 from tests import unittest
 
@@ -490,3 +491,126 @@ def _assert_peek(self, room_id, expect_code):
         self.assertEqual(
             expect_code, int(channel.result["code"]), msg=channel.result["body"],
         )
+
+
+class DeleteGroupTestCase(unittest.HomeserverTestCase):
+    servlets = [
+        admin.register_servlets,
+        login.register_servlets,
+        groups.register_servlets,
+    ]
+
+    def prepare(self, reactor, clock, hs):
+        self.store = hs.get_datastore()
+
+        self.admin_user = self.register_user("admin", "pass", admin=True)
+        self.admin_user_tok = self.login("admin", "pass")
+
+        self.other_user = self.register_user("user", "pass")
+        self.other_user_token = self.login("user", "pass")
+
+    def test_delete_group(self):
+        # Create a new group
+        request, channel = self.make_request(
+            "POST",
+            "/create_group".encode('ascii'),
+            access_token=self.admin_user_tok,
+            content={
+                "localpart": "test",
+            }
+        )
+
+        self.render(request)
+        self.assertEqual(
+            200, int(channel.result["code"]), msg=channel.result["body"],
+        )
+
+        group_id = channel.json_body["group_id"]
+
+        self._check_group(group_id, expect_code=200)
+
+        # Invite/join another user
+
+        url = "/groups/%s/admin/users/invite/%s" % (group_id, self.other_user)
+        request, channel = self.make_request(
+            "PUT",
+            url.encode('ascii'),
+            access_token=self.admin_user_tok,
+            content={}
+        )
+        self.render(request)
+        self.assertEqual(
+            200, int(channel.result["code"]), msg=channel.result["body"],
+        )
+
+        url = "/groups/%s/self/accept_invite" % (group_id,)
+        request, channel = self.make_request(
+            "PUT",
+            url.encode('ascii'),
+            access_token=self.other_user_token,
+            content={}
+        )
+        self.render(request)
+        self.assertEqual(
+            200, int(channel.result["code"]), msg=channel.result["body"],
+        )
+
+        # Check other user knows they're in the group
+        self.assertIn(group_id, self._get_groups_user_is_in(self.admin_user_tok))
+        self.assertIn(group_id, self._get_groups_user_is_in(self.other_user_token))
+
+        # Now delete the group
+        url = "/admin/delete_group/" + group_id
+        request, channel = self.make_request(
+            "POST",
+            url.encode('ascii'),
+            access_token=self.admin_user_tok,
+            content={
+                "localpart": "test",
+            }
+        )
+
+        self.render(request)
+        self.assertEqual(
+            200, int(channel.result["code"]), msg=channel.result["body"],
+        )
+
+        # Check group returns 404
+        self._check_group(group_id, expect_code=404)
+
+        # Check users don't think they're in the group
+        self.assertNotIn(group_id, self._get_groups_user_is_in(self.admin_user_tok))
+        self.assertNotIn(group_id, self._get_groups_user_is_in(self.other_user_token))
+
+    def _check_group(self, group_id, expect_code):
+        """Assert that trying to fetch the given group results in the given
+        HTTP status code
+        """
+
+        url = "/groups/%s/profile" % (group_id,)
+        request, channel = self.make_request(
+            "GET",
+            url.encode('ascii'),
+            access_token=self.admin_user_tok,
+        )
+
+        self.render(request)
+        self.assertEqual(
+            expect_code, int(channel.result["code"]), msg=channel.result["body"],
+        )
+
+    def _get_groups_user_is_in(self, access_token):
+        """Returns the list of groups the user is in (given their access token)
+        """
+        request, channel = self.make_request(
+            "GET",
+            "/joined_groups".encode('ascii'),
+            access_token=access_token,
+        )
+
+        self.render(request)
+        self.assertEqual(
+            200, int(channel.result["code"]), msg=channel.result["body"],
+        )
+
+        return channel.json_body["groups"]