Owner and group of few files and folders from Bind directory visible as nobody/nogroup within nspawn container

[RussianNeuroMancer]

Owner and group of few files and folders from Bind directory visible as nobody/nogroup when I check permission from within nspawn container.

Create testing.nspawn:

[Files]
Bind=/patch/to/folder
Use some folder with many subfolders, to expand the test coverage. Check if owners of all subfolders and files in Bind directory inside container is the same as on host.

Issue is reproducible in Ubuntu Server 17.04 (systemd 232) and Ubuntu Server 17.10 (systemd 233).

[RussianNeuroMancer (russianneuromancer)]

Issue is also reproducible for files and folder within container, if container is btrfs subvolume instead of disk image.

[RussianNeuroMancer (russianneuromancer)]

Example:

~$ LANG=C sudo whoami
sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set
~$ LANG=C ls -l /usr/bin/sudo
-rwsr-xr-x 1 nobody nogroup 140944 Jan 14 07:41 /usr/bin/sudo
~$ LANG=C ls -l /var/lib/machines/builder/usr/bin/sudo
-rwsr-xr-x 1 root root 140944 Jan 14 07:41 /var/lib/machines/builder/usr/bin/sudo

[RussianNeuroMancer (russianneuromancer)]

https://github.com/systemd/systemd/issues/5900#issuecomment-300362005