reset_machine_id: ask for forgiveness, not permission

Avoid TOCTOU by always deleting and handling the FileNotFoundError
systemd · Mar 1, 2017 · 8c91ff1 · 8c91ff1
1 parent 122d787
commit 8c91ff1
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/mkosi b/mkosi
@@ -1027,8 +1027,11 @@ def reset_machine_id(args, workspace, run_build_script):
         os.unlink(machine_id)
         open(machine_id, "w+b").close()
         dbus_machine_id = os.path.join(workspace, 'root', 'var/lib/dbus/machine-id')
-        if os.path.exists(dbus_machine_id):
+        try:
             os.unlink(dbus_machine_id)
+        except FileNotFoundError:
+            pass
+        else:
             os.symlink('../../../etc/machine-id', dbus_machine_id)
 
 def set_root_password(args, workspace, run_build_script):