PRETTY_NAME="Ubuntu 22.04.2 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.2 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy

lxc.apparmor.profile=unconfined
lxc.mount.entry = /dev/tty7 dev/tty7 none bind,optional,create=file
lxc.cgroup.devices.allow = c 4:7 rwm

root@lxcguest:/# cat /dev/tty7
cat: /dev/tty7: Operation not permitted

ubuntu@lxchost:~$ sudo lxc-create -t ubuntu -n lxcguest1 -- -r focal 
....................................................
ubuntu@lxchost:~$ sudo cp /root/ubuntu-20.04.3-live-server-amd64.iso /var/lib/lxc/lxcguest1/rootfs/root
ubuntu@lxchost:~$ sudo lxc-execute -n lxcguest1 -u 0 -- mount -o loop /root/ubuntu-20.04.3-live-server-amd64.iso /mnt/
lxc-execute: lxcguest1: utils.c: __safe_mount_beneath_at: 1106 Function not implemented - Failed to open 40(dev)
                                                                                                                mount: /mnt/: mount failed: Operation not permitted.
ubuntu@lxchost:~$ uname -a
Linux lxchost 5.4.0-48-generic #52-Ubuntu SMP Thu Sep 10 10:58:49 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
ubuntu@lxchost:~$ sudo cat /var/lib/lxc/lxcguest1/config
# Template used to create this container: /usr/share/lxc/templates/lxc-ubuntu
# Parameters passed to the template: -r focal
# For additional config options, please look at lxc.container.conf(5)

# Uncomment the following line to support nesting containers:
#lxc.include = /usr/share/lxc/config/nesting.conf
# (Be aware this has security implications)


# Common configuration
lxc.include = /usr/share/lxc/config/ubuntu.common.conf

# Container specific configuration
lxc.rootfs.path = dir:/var/lib/lxc/lxcguest1/rootfs
lxc.uts.name = lxcguest1
lxc.arch = amd64

# Network configuration
lxc.net.0.type = veth
lxc.net.0.link = lxcbr0
lxc.net.0.flags = up
lxc.net.0.hwaddr = 00:16:3e:08:39:a6
ubuntu@lxchost:~$