markup/tasks.pm: add on_fail_handler(), add to process_message()

markup/tasks.py

@@ -19,14 +19,29 @@ os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'procat2.settings')
 django.setup()
 
 from .utils import clean_path, ensure_dir, set_file_perms, WORKDIR
-from .email import reply, reply_missing, reply_no_matches
+from .email import reply, reply_missing, reply_no_matches, send_error_email
 from .matching import find_marked_products
 from .spreadsheet import write_spreadsheet
+from procat2.settings import TREE_NAME
 
 logger = get_task_logger(__name__)
 
 
-@shared_task
+def on_fail_handler(self, exc, task_id, args, kwargs, einfo):
+    """Send an email if a task throws an exception."""
+    print(str(einfo))
+    send_error_email(f'ERROR: {TREE_NAME} celery task {task_id}', str(einfo))
+
+
+# @shared_task(on_failure=on_fail_handler)
+# def test_fail(x, y):
+#     test_fail_internal()
+
+# def test_fail_internal():
+#     raise KeyError()
+
+
+@shared_task(on_failure=on_fail_handler)
 def process_message(path):
     parser = FeedParser()
     with open(path) as f: