LXC Group Mapping

[548901239]

Hi, I'm having trouble configuring group mapping for zfs mount access in my unprivileged LXC.

I have a directory /zpool/media/ on the host which I passed to the container with a mount point at /mnt/media.

On the host:

• The directory is owned by user root (uid=0) and group media (gid=1000).
• Permissions are 770 on the directory
• I have created user jellyfin (uid=1100) which is a member of the "media" group

On the LXC guest:

• I am using the root user.
• uid 0 (root) is mapped to uid 1100 on the host (jellyfin user)
• I have created a group media here as well with gid=1000 and added the root LXC user to it
• gid 1000 (media) is mapped to gid 1000 on the host (media group)

With all of this configured, I can see the mount point inside the LXC with the correct group permission. However I am unable to enter the directory. Am I missing anything else? I created a test directory inside the LXC with the same permissions and I can enter that one.

My uid/gid mapping in the lxc config:

lxc.idmap: u 0 1100 1

lxc.idmap: u 1 100000 65535

lxc.idmap: g 0 100000 1000

lxc.idmap: g 1000 1000 1

lxc.idmap: g 1001 101001 64534

If I map the root group (gid=0) in LXC to media group on the host it works. However I would like to get this working from the media group inside the LXC.