start introducing modules

zfs_backup/misc.py

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+from os import getuid
+from pathlib import Path
+
+from typing import Any
+
+DISK_BY_UUID = Path("/dev/disk/by-uuid")
+MAPPER_PATH = Path("/dev/mapper")
+
+
+def assert_type(instance: Any, object_type: Any, message: str) -> None:
+    if not isinstance(instance, object_type):
+        raise TypeError(message)
+
+
+def verify_running_as_root() -> None:
+    if getuid() > 0:
+        raise PermissionError("Run as root.")