Implement an `on_new_event` callback (#11126)

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
pull/11187/head
Brendan Abolivier 2021-10-26 15:17:36 +02:00 committed by GitHub
parent 7004f43da1
commit c7a5e49664
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8 changed files with 165 additions and 12 deletions

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@ -0,0 +1 @@
Add an `on_new_event` third-party rules callback to allow Synapse modules to act after an event has been sent into a room.

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@ -119,6 +119,27 @@ callback returns `True`, Synapse falls through to the next one. The value of the
callback that does not return `True` will be used. If this happens, Synapse will not call
any of the subsequent implementations of this callback.
### `on_new_event`
_First introduced in Synapse v1.47.0_
```python
async def on_new_event(
event: "synapse.events.EventBase",
state_events: "synapse.types.StateMap",
) -> None:
```
Called after sending an event into a room. The module is passed the event, as well
as the state of the room _after_ the event. This means that if the event is a state event,
it will be included in this state.
Note that this callback is called when the event has already been processed and stored
into the room, which means this callback cannot be used to deny persisting the event. To
deny an incoming event, see [`check_event_for_spam`](spam_checker_callbacks.md#check_event_for_spam) instead.
If multiple modules implement this callback, Synapse runs them all in order.
## Example
The example below is a module that implements the third-party rules callback

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@ -36,6 +36,7 @@ CHECK_THREEPID_CAN_BE_INVITED_CALLBACK = Callable[
CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK = Callable[
[str, StateMap[EventBase], str], Awaitable[bool]
]
ON_NEW_EVENT_CALLBACK = Callable[[EventBase, StateMap[EventBase]], Awaitable]
def load_legacy_third_party_event_rules(hs: "HomeServer") -> None:
@ -152,6 +153,7 @@ class ThirdPartyEventRules:
self._check_visibility_can_be_modified_callbacks: List[
CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
] = []
self._on_new_event_callbacks: List[ON_NEW_EVENT_CALLBACK] = []
def register_third_party_rules_callbacks(
self,
@ -163,6 +165,7 @@ class ThirdPartyEventRules:
check_visibility_can_be_modified: Optional[
CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
] = None,
on_new_event: Optional[ON_NEW_EVENT_CALLBACK] = None,
) -> None:
"""Register callbacks from modules for each hook."""
if check_event_allowed is not None:
@ -181,6 +184,9 @@ class ThirdPartyEventRules:
check_visibility_can_be_modified,
)
if on_new_event is not None:
self._on_new_event_callbacks.append(on_new_event)
async def check_event_allowed(
self, event: EventBase, context: EventContext
) -> Tuple[bool, Optional[dict]]:
@ -321,6 +327,31 @@ class ThirdPartyEventRules:
return True
async def on_new_event(self, event_id: str) -> None:
"""Let modules act on events after they've been sent (e.g. auto-accepting
invites, etc.)
Args:
event_id: The ID of the event.
Raises:
ModuleFailureError if a callback raised any exception.
"""
# Bail out early without hitting the store if we don't have any callbacks
if len(self._on_new_event_callbacks) == 0:
return
event = await self.store.get_event(event_id)
state_events = await self._get_state_map_for_room(event.room_id)
for callback in self._on_new_event_callbacks:
try:
await callback(event, state_events)
except Exception as e:
logger.exception(
"Failed to run module API callback %s: %s", callback, e
)
async def _get_state_map_for_room(self, room_id: str) -> StateMap[EventBase]:
"""Given a room ID, return the state events of that room.

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@ -1916,7 +1916,7 @@ class FederationEventHandler:
event_pos = PersistedEventPosition(
self._instance_name, event.internal_metadata.stream_ordering
)
self._notifier.on_new_room_event(
await self._notifier.on_new_room_event(
event, event_pos, max_stream_token, extra_users=extra_users
)

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@ -1537,13 +1537,16 @@ class EventCreationHandler:
# If there's an expiry timestamp on the event, schedule its expiry.
self._message_handler.maybe_schedule_expiry(event)
def _notify() -> None:
async def _notify() -> None:
try:
self.notifier.on_new_room_event(
await self.notifier.on_new_room_event(
event, event_pos, max_stream_token, extra_users=extra_users
)
except Exception:
logger.exception("Error notifying about new room event")
logger.exception(
"Error notifying about new room event %s",
event.event_id,
)
run_in_background(_notify)

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@ -220,6 +220,8 @@ class Notifier:
# down.
self.remote_server_up_callbacks: List[Callable[[str], None]] = []
self._third_party_rules = hs.get_third_party_event_rules()
self.clock = hs.get_clock()
self.appservice_handler = hs.get_application_service_handler()
self._pusher_pool = hs.get_pusherpool()
@ -267,7 +269,7 @@ class Notifier:
"""
self.replication_callbacks.append(cb)
def on_new_room_event(
async def on_new_room_event(
self,
event: EventBase,
event_pos: PersistedEventPosition,
@ -275,9 +277,10 @@ class Notifier:
extra_users: Optional[Collection[UserID]] = None,
):
"""Unwraps event and calls `on_new_room_event_args`."""
self.on_new_room_event_args(
await self.on_new_room_event_args(
event_pos=event_pos,
room_id=event.room_id,
event_id=event.event_id,
event_type=event.type,
state_key=event.get("state_key"),
membership=event.content.get("membership"),
@ -285,9 +288,10 @@ class Notifier:
extra_users=extra_users or [],
)
def on_new_room_event_args(
async def on_new_room_event_args(
self,
room_id: str,
event_id: str,
event_type: str,
state_key: Optional[str],
membership: Optional[str],
@ -302,7 +306,10 @@ class Notifier:
listening to the room, and any listeners for the users in the
`extra_users` param.
The events can be peristed out of order. The notifier will wait
This also notifies modules listening on new events via the
`on_new_event` callback.
The events can be persisted out of order. The notifier will wait
until all previous events have been persisted before notifying
the client streams.
"""
@ -318,6 +325,8 @@ class Notifier:
)
self._notify_pending_new_room_events(max_room_stream_token)
await self._third_party_rules.on_new_event(event_id)
self.notify_replication()
def _notify_pending_new_room_events(self, max_room_stream_token: RoomStreamToken):

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@ -207,11 +207,12 @@ class ReplicationDataHandler:
max_token = self.store.get_room_max_token()
event_pos = PersistedEventPosition(instance_name, token)
self.notifier.on_new_room_event_args(
await self.notifier.on_new_room_event_args(
event_pos=event_pos,
max_room_stream_token=max_token,
extra_users=extra_users,
room_id=row.data.room_id,
event_id=row.data.event_id,
event_type=row.data.type,
state_key=row.data.state_key,
membership=row.data.membership,

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@ -15,7 +15,7 @@ import threading
from typing import TYPE_CHECKING, Dict, Optional, Tuple
from unittest.mock import Mock
from synapse.api.constants import EventTypes
from synapse.api.constants import EventTypes, Membership
from synapse.api.errors import SynapseError
from synapse.events import EventBase
from synapse.events.third_party_rules import load_legacy_third_party_event_rules
@ -25,6 +25,7 @@ from synapse.types import JsonDict, Requester, StateMap
from synapse.util.frozenutils import unfreeze
from tests import unittest
from tests.test_utils import make_awaitable
if TYPE_CHECKING:
from synapse.module_api import ModuleApi
@ -74,7 +75,7 @@ class LegacyChangeEvents(LegacyThirdPartyRulesTestModule):
return d
class ThirdPartyRulesTestCase(unittest.HomeserverTestCase):
class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
servlets = [
admin.register_servlets,
login.register_servlets,
@ -86,11 +87,29 @@ class ThirdPartyRulesTestCase(unittest.HomeserverTestCase):
load_legacy_third_party_event_rules(hs)
# We're not going to be properly signing events as our remote homeserver is fake,
# therefore disable event signature checks.
# Note that these checks are not relevant to this test case.
# Have this homeserver auto-approve all event signature checking.
async def approve_all_signature_checking(_, pdu):
return pdu
hs.get_federation_server()._check_sigs_and_hash = approve_all_signature_checking
# Have this homeserver skip event auth checks. This is necessary due to
# event auth checks ensuring that events were signed by the sender's homeserver.
async def _check_event_auth(origin, event, context, *args, **kwargs):
return context
hs.get_federation_event_handler()._check_event_auth = _check_event_auth
return hs
def prepare(self, reactor, clock, homeserver):
# Create a user and room to play with during the tests
# Create some users and a room to play with during the tests
self.user_id = self.register_user("kermit", "monkey")
self.invitee = self.register_user("invitee", "hackme")
self.tok = self.login("kermit", "monkey")
# Some tests might prevent room creation on purpose.
@ -424,6 +443,74 @@ class ThirdPartyRulesTestCase(unittest.HomeserverTestCase):
self.assertEqual(channel.code, 200)
self.assertEqual(channel.json_body["i"], i)
def test_on_new_event(self):
"""Test that the on_new_event callback is called on new events"""
on_new_event = Mock(make_awaitable(None))
self.hs.get_third_party_event_rules()._on_new_event_callbacks.append(
on_new_event
)
# Send a message event to the room and check that the callback is called.
self.helper.send(room_id=self.room_id, tok=self.tok)
self.assertEqual(on_new_event.call_count, 1)
# Check that the callback is also called on membership updates.
self.helper.invite(
room=self.room_id,
src=self.user_id,
targ=self.invitee,
tok=self.tok,
)
self.assertEqual(on_new_event.call_count, 2)
args, _ = on_new_event.call_args
self.assertEqual(args[0].membership, Membership.INVITE)
self.assertEqual(args[0].state_key, self.invitee)
# Check that the invitee's membership is correct in the state that's passed down
# to the callback.
self.assertEqual(
args[1][(EventTypes.Member, self.invitee)].membership,
Membership.INVITE,
)
# Send an event over federation and check that the callback is also called.
self._send_event_over_federation()
self.assertEqual(on_new_event.call_count, 3)
def _send_event_over_federation(self) -> None:
"""Send a dummy event over federation and check that the request succeeds."""
body = {
"origin": self.hs.config.server.server_name,
"origin_server_ts": self.clock.time_msec(),
"pdus": [
{
"sender": self.user_id,
"type": EventTypes.Message,
"state_key": "",
"content": {"body": "hello world", "msgtype": "m.text"},
"room_id": self.room_id,
"depth": 0,
"origin_server_ts": self.clock.time_msec(),
"prev_events": [],
"auth_events": [],
"signatures": {},
"unsigned": {},
}
],
}
channel = self.make_request(
method="PUT",
path="/_matrix/federation/v1/send/1",
content=body,
federation_auth_origin=self.hs.config.server.server_name.encode("utf8"),
)
self.assertEqual(channel.code, 200, channel.result)
def _update_power_levels(self, event_default: int = 0):
"""Updates the room's power levels.