added create / compare hashes and notify on miss-match for MinIO backups;

middleware/app_be/services/minioservice.py

@@ -1,3 +1,5 @@
+from typing import Union
+
 import requests
 from django.conf import settings
 
@@ -31,11 +33,11 @@ class MinioService:
         :param filename: filename
         :return: bytes representation of the file or None on error
         """
-        file_bytes: bytes
+        file_bytes: Union[bytes, None] = None
         try:
             url = settings.AWS_HOST + filename
             response = requests.get(url, stream=True)
             file_bytes=response.content
         except:
             print("Error downloading file from minio")
-        return file_bytes
+        return file_bytes