Returns NULL If File Doesn't Exist

storage_service/controller/storage_controller.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from storage_service.depends.depend_queue import dependency_queue
 from storage_service.depends.depend_s3_service import (
     dependency_storage_service,
@@ -36,7 +38,7 @@ class StorageController:
         )
 
     @s3_router.get("/file_url/", status_code=200)
-    def file_url(self, username: str, file_postfix: str) -> dict[str, str]:
+    def file_url(self, username: str, file_postfix: str) -> dict[str, str | None]:
         return self.storage_service.get_temp_read_link(
             file_name_hash(username, file_postfix)
         )

storage_service/service/amazon_s3_service.py

@@ -36,7 +36,7 @@ class AmazonS3Service(StorageService):
             "file_key": self._get_object_url(file_name),
         }
 
-    def get_temp_read_link(self, file_name) -> dict[str, str | Any]:
+    def get_temp_read_link(self, file_name) -> dict[str, str | None]:
         return {"presigned_url": self._get_presigned_read_url(file_name)}
 
     def process_file(self, file_name: str, file_type: FileType = FileType.PNG) -> None:
@@ -59,12 +59,16 @@ class AmazonS3Service(StorageService):
             ExpiresIn=self.expires_in,
         )
 
-    def _get_presigned_read_url(self, file_name) -> str:
+    def _get_presigned_read_url(self, file_name) -> str | None:
+        result = self.s3.list_objects(Bucket=self.bucket_name, Prefix=file_name)
+
+        if file_name in map(lambda x: x["Key"], result["Contents"]):
             return self.s3.generate_presigned_url(
                 "get_object",
                 Params={"Bucket": self.bucket_name, "Key": file_name},
                 ExpiresIn=self.expires_in,
             )
+        return None
 
     def _get_file_obj(self, file_name: str) -> io.BytesIO:
         return io.BytesIO(

storage_service/service/storage_service.py

@@ -17,7 +17,7 @@ class StorageService(ABC):
         pass
 
     @abstractmethod
-    def get_temp_read_link(self, file_name) -> dict[str, str | Any]:
+    def get_temp_read_link(self, file_name) -> dict[str, str | None]:
         pass
 
     @abstractmethod