Log a warning when being ratelimtted by Github

pydis_site/apps/api/tests/test_github_webhook_filter.py

@@ -1,8 +1,10 @@
 from unittest import mock
+from urllib.error import HTTPError
 
 from django.urls import reverse
 from rest_framework.test import APITestCase
 
+from pydis_site.apps.api.views import GitHubWebhookFilterView
 
 class GitHubWebhookFilterAPITests(APITestCase):
     def test_ignores_bot_sender(self):
@@ -44,3 +46,17 @@ def test_accepts_interesting_events(self):
             response = self.client.post(url, data=payload, headers=headers)
             self.assertEqual(response.status_code, context_mock.status)
             self.assertEqual(response.headers.get('X-Clacks-Overhead'), 'Joe Armstrong')
+
+def test_rate_limit_is_logged_to_sentry(self):
+    url = reverse('api:github-webhook-filter', args=('id', 'token'))
+    payload = {}
+    headers = {'X-GitHub-Event': 'pull_request_review'}
+    with (
+        mock.patch('urllib.request.urlopen') as urlopen,
+        mock.patch.object(GitHubWebhookFilterView, "logger") as logger,
+    ):
+        urlopen.side_effect = HTTPError(None, 429, 'Too Many Requests', {}, None)
+        self.client.post(url, data=payload, headers=headers)
+
+        logger.warning = mock.PropertyMock()
+        logger.warning.assert_called_once()

pydis_site/apps/api/views.py

@@ -1,6 +1,8 @@
 import json
+import logging
 import urllib.request
 from collections.abc import Mapping
+from http import HTTPStatus
 
 from rest_framework import status
 from rest_framework.exceptions import ParseError
@@ -254,6 +256,7 @@ class GitHubWebhookFilterView(APIView):
 
     authentication_classes = ()
     permission_classes = ()
+    logger = logging.getLogger("github_webhook_filter")
 
     def post(self, request: Request, *, webhook_id: str, webhook_token: str) -> Response:
         """Filter a webhook POST from GitHub before sending it to Discord."""
@@ -329,4 +332,10 @@ def send_webhook(
             with urllib.request.urlopen(request) as response:  # noqa: S310
                 return (response.status, dict(response.getheaders()), response.read())
         except urllib.error.HTTPError as err:  # pragma: no cover
+            if err.code == HTTPStatus.TOO_MANY_REQUESTS:
+                self.logger.warning(
+                    "We are being rate limited by Github! Scope: %s, reset-after: %d",
+                    headers.get("X-RateLimit-Scope"),
+                    headers.get("X-RateLimit-Reset-After"),
+                )
             return (err.code, dict(err.headers), err.fp.read())