fix(oci): reject missing managed mount roots

oci/remote/oci_managed_volumes.py

@@ -84,10 +84,7 @@ def remove_empty_format_directories(rootfs, deployment, backed_only=True, target
     if not paths:
         return 0
     flags = os.O_RDONLY | os.O_DIRECTORY | os.O_NOFOLLOW
-    try:
     root = os.open(rootfs, flags)
-    except FileNotFoundError:
-        return 0
     removed = 0
     try:
         for path in paths:
@@ -98,8 +95,6 @@ def remove_empty_format_directories(rootfs, deployment, backed_only=True, target
                     os.close(current)
                     current = following
                 removed += int(remove_empty_at(current))
-            except FileNotFoundError:
-                continue
             except OSError as error:
                 if error.errno in (errno.ELOOP, errno.ENOTDIR):
                     raise ValueError('Symbolic link or invalid managed volume path') from error

oci/tests/test_managed_volume_startup.py

@@ -174,6 +174,21 @@ class FormatDirectoryTests(unittest.TestCase):
             opened.assert_not_called()
 
 
+    def test_missing_rootfs_is_an_error_without_remove(self):
+        with tempfile.TemporaryDirectory() as tmp, patch.object(volumes.os, 'rmdir') as remove:
+            with self.assertRaises(FileNotFoundError):
+                volumes.remove_empty_format_directories(Path(tmp) / 'missing', {'mounts': [
+                    {'container_path': '/config', 'type': 'managed-volume', 'backup': True}]})
+            remove.assert_not_called()
+
+    def test_missing_managed_mount_is_an_error_without_remove(self):
+        with tempfile.TemporaryDirectory() as tmp, patch.object(volumes.os, 'rmdir') as remove:
+            with self.assertRaises(FileNotFoundError):
+                volumes.remove_empty_format_directories(Path(tmp), {'mounts': [
+                    {'container_path': '/missing', 'type': 'managed-volume', 'backup': True}]})
+            remove.assert_not_called()
+
+
 class StartupContractTests(unittest.TestCase):
     def setUp(self):
         directory = tempfile.TemporaryDirectory(); self.addCleanup(directory.cleanup)