Added run_in_ns_wrapper to only run in namespace when root is detected.

granulate_utils/linux/ns.py

@@ -19,6 +19,7 @@
 import os
 import re
 from collections import deque
+from functools import lru_cache
 from pathlib import Path
 from threading import Thread
 from typing import Callable, Collection, List, Optional, TypeVar, Union
@@ -273,6 +274,21 @@ def _switch_and_run():
         return ret
 
 
+@lru_cache(maxsize=None)
+def is_root() -> bool:
+    return os.geteuid() == 0
+
+
+def run_in_ns_wrapper(
+    nstypes: List[str],
+    callback: Callable[[], T],
+    target_pid: int = 1,
+) -> T:
+    if is_root():
+        return run_in_ns(nstypes, callback, target_pid)
+    return callback()
+
+
 def get_mnt_ns_ancestor(process: Process) -> Process:
     """
     Gets the topmost ancestor of "process" that runs in the same mount namespace of "process".

granulate_utils/metadata/cloud.py

@@ -26,7 +26,7 @@
 
 from granulate_utils.exceptions import BadResponseCode
 from granulate_utils.futures import call_in_parallel
-from granulate_utils.linux.ns import run_in_ns
+from granulate_utils.linux.ns import run_in_ns_wrapper
 from granulate_utils.metadata import Metadata
 
 METADATA_REQUEST_TIMEOUT = 5
@@ -229,7 +229,7 @@ def _fetch() -> Optional[Metadata]:
         return None
 
     try:
-        metadata = run_in_ns(["net"], _fetch)
+        metadata = run_in_ns_wrapper(["net"], _fetch)
         if metadata is not None:
             return metadata
     except TimeoutError as exception: