[SOLVED] Reset UID/GID mappings

[uruloki01]

I have been trying to work my way through using bind mounts in unprivileged containers (https://pve.proxmox.com/wiki/Unprivileged_LXC_containers#Using_local_directory_bind_mount_points). Since I have been unable to get it to work, I tried resetting everything to try again to the point of wiping out my containers and clearing out /etc/subuid and /etc/subgid. Now, I can't make any containers.

  Logical volume "vm-101-disk-0" created.
mke2fs 1.44.5 (15-Dec-2018)
Discarding device blocks:    4096/3932160               done                           
Creating filesystem with 3932160 4k blocks and 983040 inodes
Filesystem UUID: 00d81563-4df1-41dc-a619-0fea5f3db505
Superblock backups stored on blocks:
    32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208

Allocating group tables:   0/120       done                           
Writing inode tables:   0/120       done                           
Creating journal (16384 blocks): done
Multiple mount protection is enabled with update interval 5 seconds.
Writing superblocks and filesystem accounting information:   0/120       done

extracting archive '/var/lib/vz/template/cache/ubuntu-20.04-standard_20.04-1_amd64.tar.gz'
lxc 20200628201057.948 ERROR    conf - conf.c:lxc_map_ids:2779 - newuidmap failed to write mapping "newuidmap: uid range [0-65536) -> [100000-165536) not allowed": newuidmap 27570 0 100000 65536
Failed to write id mapping for child process
lxc 20200628201057.948 ERROR    utils - utils.c:lxc_switch_uid_gid:1341 - Invalid argument - Failed to switch to gid 0
  Logical volume "vm-101-disk-0" successfully removed
TASK ERROR: unable to create CT 101 - command 'lxc-usernsexec -m u:0:100000:65536 -m g:0:100000:65536 -- tar xpf - -z --totals --one-file-system -p --sparse --numeric-owner --acls --xattrs '--xattrs-include=user.*' '--xattrs-include=security.capability' '--warning=no-file-ignored' '--warning=no-xattr-write' -C /var/lib/lxc/101/rootfs --skip-old-files --anchored --exclude './dev/*'' failed: exit code 1

Where is the mapping coming from that is trying to change 27570?
What are the default values for /etc/subuid and /etc/subgid? I have tried with blank and with root:1000:1 in them.

 

[fiona]

Hi,
seems like it ends up using the process ID for some reason if there is no /etc/sub{g,u}id file.
The default content in both files is:

root:100000:65536

EDIT: It's not actually trying to use the process ID as part of the mapping, that's just log information. When /etc/subuid is empty or doesn't allow the range LXC wants to map (i.e. 100000 to 165535), then of course LXC fails.