fixup! Make mirror_file fail if file object already exists (#7134)

Author: nadove-ucsc

src/azul/indexer/mirror_controller.py

@@ -154,6 +154,8 @@ def mirror_file(self,
                                 and catalog not in config.integration_test_catalogs)
         if self.service.info_exists(catalog, file):
             log.info('File is already mirrored, skipping upload: %r', file)
+        elif self.service.file_exists(catalog, file):
+            assert False, R('File object is already present', file)
         elif file_is_large and not deployment_is_stable:
             log.info('Not mirroring file to save cost: %r', file)
         else:

src/azul/indexer/mirror_service.py

@@ -194,6 +194,14 @@ def info_object_key(self, file: File) -> str:
     def info_exists(self, catalog: CatalogName, file: File) -> bool:
         return self._get_info(catalog, file) is not None
 
+    def file_exists(self, catalog: CatalogName, file: File) -> bool:
+        try:
+            self._storage(catalog).head(self.mirror_object_key(file))
+        except StorageObjectNotFound:
+            return False
+        else:
+            return True
+
     def _file_key(self, prefix: str, file: File, *, extension: str = '') -> str:
         digest = file.digest
         assert all(c in string.hexdigits for c in digest.value), R(