feat(processing): add unblob dedicated temporary directory handling

Author: qkaiser

python/unblob/processing.py

@@ -1,8 +1,11 @@
+import atexit
 import multiprocessing
+import os
 import shutil
 from collections.abc import Iterable, Sequence
 from operator import attrgetter
 from pathlib import Path
+import tempfile
 from typing import Optional, Union
 
 import attrs
@@ -100,6 +103,21 @@ class ExtractionConfig:
     dir_handlers: DirectoryHandlers = BUILTIN_DIR_HANDLERS
     verbose: int = 1
     progress_reporter: type[ProgressReporter] = NullProgressReporter
+    tmp_dir: Path = attrs.field(factory=lambda: Path(tempfile.mkdtemp(prefix="unblob-tmp-")))
+
+    def __attrs_post_init__(self):
+        """Set environment variables so all subprocesses and handlers use our temp dir"""
+        for var in ("TMP", "TMPDIR", "TEMP", "TEMPDIR"):
+            os.environ[var] = self.tmp_dir.as_posix()
+        atexit.register(self._cleanup_tmp_dir)
+
+    def _cleanup_tmp_dir(self):
+        """Remove the temp directory and its contents at the end of the run"""
+        if self.tmp_dir.exists():
+            try:
+                shutil.rmtree(self.tmp_dir)
+            except Exception as e:
+                logger.warning("Failed to clean up tmp_dir", tmp_dir=self.tmp_dir, exc_info=e)
 
     def _get_output_path(self, path: Path) -> Path:
         """Return path under extract root."""

python/unblob/sandbox.py

@@ -55,6 +55,10 @@ def __init__(
             AccessFS.remove_file(config.extract_root),
             AccessFS.make_dir(config.extract_root.parent),
             AccessFS.read_write(log_path),
+            # Allow access to the managed temp directory for handlers
+            AccessFS.read_write(config.tmp_dir),
+            AccessFS.remove_dir(config.tmp_dir),
+            AccessFS.remove_file(config.tmp_dir),
             *extra_passthrough,
         ]
 

tests/test_cli.py

@@ -1,5 +1,6 @@
 from collections.abc import Iterable
 from pathlib import Path
+import tempfile
 from typing import Optional
 from unittest import mock