From 6ee61b905256f87dc2b75007ed711cd59065db9a Mon Sep 17 00:00:00 2001
From: Sean Quah <8349537+squahtx@users.noreply.github.com>
Date: Wed, 11 May 2022 14:52:26 +0100
Subject: [PATCH] Complain if a federation endpoint has the `@cancellable` flag
(#12705)
`BaseFederationServlet` wraps its endpoints in a bunch of async code
that has not been vetted for compatibility with cancellation.
Fail CI if a `@cancellable` flag is applied to a federation endpoint.
Signed-off-by: Sean Quah <seanq@element.io>
---
changelog.d/12705.misc | 1 +
synapse/federation/transport/server/_base.py | 13 ++++++++++++-
tests/federation/transport/server/test__base.py | 2 ++
3 files changed, 15 insertions(+), 1 deletion(-)
create mode 100644 changelog.d/12705.misc
diff --git a/changelog.d/12705.misc b/changelog.d/12705.misc
new file mode 100644
index 0000000000..a913d8bb85
--- /dev/null
+++ b/changelog.d/12705.misc
@@ -0,0 +1 @@
+Complain if a federation endpoint has the `@cancellable` flag, since some of the wrapper code may not handle cancellation correctly yet.
diff --git a/synapse/federation/transport/server/_base.py b/synapse/federation/transport/server/_base.py
index d629a3ecb5..103861644a 100644
--- a/synapse/federation/transport/server/_base.py
+++ b/synapse/federation/transport/server/_base.py
@@ -21,7 +21,7 @@ from typing import TYPE_CHECKING, Any, Awaitable, Callable, Dict, Optional, Tupl
from synapse.api.errors import Codes, FederationDeniedError, SynapseError
from synapse.api.urls import FEDERATION_V1_PREFIX
-from synapse.http.server import HttpServer, ServletCallback
+from synapse.http.server import HttpServer, ServletCallback, is_method_cancellable
from synapse.http.servlet import parse_json_object_from_request
from synapse.http.site import SynapseRequest
from synapse.logging.context import run_in_background
@@ -373,6 +373,17 @@ class BaseFederationServlet:
if code is None:
continue
+ if is_method_cancellable(code):
+ # The wrapper added by `self._wrap` will inherit the cancellable flag,
+ # but the wrapper itself does not support cancellation yet.
+ # Once resolved, the cancellation tests in
+ # `tests/federation/transport/server/test__base.py` can be re-enabled.
+ raise Exception(
+ f"{self.__class__.__name__}.on_{method} has been marked as "
+ "cancellable, but federation servlets do not support cancellation "
+ "yet."
+ )
+
server.register_paths(
method,
(pattern,),
diff --git a/tests/federation/transport/server/test__base.py b/tests/federation/transport/server/test__base.py
index 98a951f03e..ac3695a8cc 100644
--- a/tests/federation/transport/server/test__base.py
+++ b/tests/federation/transport/server/test__base.py
@@ -59,6 +59,8 @@ class BaseFederationServletCancellationTests(
):
"""Tests for `BaseFederationServlet` cancellation."""
+ skip = "`BaseFederationServlet` does not support cancellation yet."
+
path = f"{CancellableFederationServlet.PREFIX}{CancellableFederationServlet.PATH}"
def create_test_resource(self):
--
GitLab