zulip_update: Catch and carry on if a realm fails.

It is better to log the exception and _try_ all realms, than to fail
early due to a bad realm and fail to notify the rest.

zerver/lib/import_realm.py

@@ -40,7 +40,7 @@ from zerver.lib.user_counts import realm_user_count_by_role
 from zerver.lib.user_groups import create_system_user_groups_for_realm
 from zerver.lib.user_message import UserMessageLite, bulk_insert_ums
 from zerver.lib.utils import generate_api_key, process_list_in_batches
-from zerver.lib.zulip_update_announcements import send_zulip_update_announcements
+from zerver.lib.zulip_update_announcements import send_zulip_update_announcements_to_realm
 from zerver.models import (
     AlertWord,
     Attachment,
@@ -1559,7 +1559,9 @@ def do_import_realm(import_dir: Path, subdomain: str, processes: int = 1) -> Rea
         realm=realm, event_type=RealmAuditLog.REALM_EXPORTED, acting_user=None
     ).exists()
     if not is_realm_imported_from_other_zulip_server:
-        send_zulip_update_announcements(skip_delay=False, realm_imported_from_other_product=realm)
+        send_zulip_update_announcements_to_realm(
+            realm, skip_delay=False, realm_imported_from_other_product=True
+        )
 
     return realm
 

zerver/lib/zulip_update_announcements.py

@@ -1,3 +1,4 @@
+import logging
 from dataclasses import dataclass
 from datetime import timedelta
 from typing import List, Optional
@@ -220,21 +221,21 @@ def send_messages_and_update_level(
     realm.save(update_fields=["zulip_update_announcements_level"])
 
 
-def send_zulip_update_announcements(
-    skip_delay: bool, realm_imported_from_other_product: Optional[Realm] = None
+def send_zulip_update_announcements(skip_delay: bool) -> None:
+    latest_zulip_update_announcements_level = get_latest_zulip_update_announcements_level()
+    for realm in get_realms_behind_zulip_update_announcements_level(
+        level=latest_zulip_update_announcements_level
+    ):
+        try:
+            send_zulip_update_announcements_to_realm(realm, skip_delay)
+        except Exception as e:  # nocoverage
+            logging.exception(e)
+
+
+def send_zulip_update_announcements_to_realm(
+    realm: Realm, skip_delay: bool, realm_imported_from_other_product: bool = False
 ) -> None:
     latest_zulip_update_announcements_level = get_latest_zulip_update_announcements_level()
-
-    if realm_imported_from_other_product:
-        realms = [realm_imported_from_other_product]
-    else:
-        realms = list(
-            get_realms_behind_zulip_update_announcements_level(
-                level=latest_zulip_update_announcements_level
-            )
-        )
-
-    for realm in realms:
     # Refresh the realm from the database and check its
     # properties, to protect against racing with another copy of
     # ourself.
@@ -275,7 +276,7 @@ def send_zulip_update_announcements(
             and is_group_direct_message_sent_to_admins_within_days(realm, days=1)
             and not skip_delay
         ):
-                continue
+            return
 
         # Send an introductory message just before the first update message.
         with override_language(realm.default_language):
@@ -283,9 +284,7 @@ def send_zulip_update_announcements(
 
         stream = realm.zulip_update_announcements_stream
         assert stream.recipient_id is not None
-            topic_has_messages = messages_for_topic(
-                realm.id, stream.recipient_id, topic_name
-            ).exists()
+        topic_has_messages = messages_for_topic(realm.id, stream.recipient_id, topic_name).exists()
 
         if not topic_has_messages:
             content_of_introductory_message = (