push_notifications: Fix handling of 500s from bouncer.

The comments explain the context, but we shouldn't mark our access to
push notifications as disabled incorrectly here.

zerver/lib/push_notifications.py

@@ -44,6 +44,7 @@ from zerver.lib.exceptions import ErrorCode, JsonableError
 from zerver.lib.message import access_message, huddle_users
 from zerver.lib.outgoing_http import OutgoingSession
 from zerver.lib.remote_server import (
+    PushNotificationBouncerServerError,
     send_json_to_push_bouncer,
     send_realms_only_to_push_bouncer,
     send_to_push_bouncer,
@@ -786,6 +787,12 @@ def initialize_push_notifications() -> None:
 
         try:
             realms = send_realms_only_to_push_bouncer()
+        except PushNotificationBouncerServerError:  # nocoverage
+            # 50x errors from the bouncer cannot be addressed by the
+            # administrator of this server, and may be localized to
+            # this endpoint; don't rashly mark push notifications as
+            # disabled when they are likely working perfectly fine.
+            pass
         except Exception:
             # An exception was thrown trying to ask the bouncer service whether we can send
             # push notifications or not. There may be certain transient failures that we could

zerver/lib/remote_server.py

@@ -32,6 +32,10 @@ class PushNotificationBouncerRetryLaterError(JsonableError):
     http_status_code = 502
 
 
+class PushNotificationBouncerServerError(PushNotificationBouncerRetryLaterError):
+    http_status_code = 502
+
+
 class RealmDataForAnalytics(BaseModel):
     model_config = ConfigDict(extra="forbid")
 
@@ -114,7 +118,7 @@ def send_to_push_bouncer(
         # to the callers that the attempt failed and they can retry.
         error_msg = "Received 500 from push notification bouncer"
         logging.warning(error_msg)
-        raise PushNotificationBouncerRetryLaterError(error_msg)
+        raise PushNotificationBouncerServerError(error_msg)
     elif res.status_code >= 400:
         # If JSON parsing errors, just let that exception happen
         result_dict = orjson.loads(res.content)

zerver/tests/test_push_notifications.py

@@ -62,6 +62,7 @@ from zerver.lib.push_notifications import (
 from zerver.lib.remote_server import (
     PushNotificationBouncerError,
     PushNotificationBouncerRetryLaterError,
+    PushNotificationBouncerServerError,
     build_analytics_data,
     get_realms_info_for_push_bouncer,
     send_analytics_to_push_bouncer,
@@ -906,7 +907,7 @@ class PushBouncerNotificationTest(BouncerTestCase):
             with responses.RequestsMock() as resp, self.assertLogs(level="WARNING") as warn_log:
                 resp.add(responses.POST, URL, body=orjson.dumps({"msg": "error"}), status=500)
                 with self.assertRaisesRegex(
-                    PushNotificationBouncerRetryLaterError,
+                    PushNotificationBouncerServerError,
                     r"Received 500 from push notification bouncer$",
                 ):
                     self.client_post(endpoint, {"token": token, **appid}, subdomain="zulip")
@@ -3492,7 +3493,7 @@ class TestSendToPushBouncer(ZulipTestCase):
     def test_500_error(self) -> None:
         self.add_mock_response(status=500)
         with self.assertLogs(level="WARNING") as m:
-            with self.assertRaises(PushNotificationBouncerRetryLaterError):
+            with self.assertRaises(PushNotificationBouncerServerError):
                 send_to_push_bouncer("POST", "register", {"data": "true"})
             self.assertEqual(m.output, ["WARNING:root:Received 500 from push notification bouncer"])