limit extraction dir to one on archives

CHANGELOG.md

@@ -16,6 +16,7 @@ This project adheres to [Semantic Versioning](http://semver.org/) and [Keep a Ch
 - Update session manager to pass toolchain role region to sts
 
 ### Fixes
+- correct archive extraction when there is only one nested path (issue 749)
 
 ## v5.0.0 (2024-08-16)
 

seedfarmer/mgmt/archive_support.py

@@ -72,12 +72,26 @@ def _download_archive(archive_url: str, secret_name: Optional[str]) -> Response:
 def _extract_archive(archive_name: str, extracted_dir_path: str) -> str:
     if archive_name.endswith(".tar.gz"):
         with tarfile.open(archive_name, "r:gz") as tar_file:
-            embedded_dir = os.path.commonprefix(tar_file.getnames())
-            tar_file.extractall(extracted_dir_path)
+            all_members = tar_file.getmembers()
+            top_level_dirs = set(member.name.split("/")[0] for member in all_members)
+            if len(top_level_dirs) == 1:
+                embedded_dir = top_level_dirs.pop()
+            else:
+                embedded_dir = ""
+            members_to_extract = [m for m in all_members]
+            tar_file.extractall(extracted_dir_path, members=members_to_extract)
     else:
         with ZipFile(archive_name, "r") as zip_file:
-            embedded_dir = os.path.commonprefix(zip_file.namelist())
-            zip_file.extractall(extracted_dir_path)
+            all_files = zip_file.namelist()
+            top_level_dirs = set(name.split("/")[0] for name in all_files if name.endswith("/"))
+            if len(top_level_dirs) == 1:
+                embedded_dir = top_level_dirs.pop()
+            else:
+                embedded_dir = ""
+            files_to_extract = [f for f in all_files]  # ]
+
+            for file in files_to_extract:
+                zip_file.extract(file, path=extracted_dir_path)
 
     return embedded_dir