mcroce@mcroce-redhat:~$ hostname
mcroce-redhat
mcroce@mcroce-redhat:~$ sudo unshare -u
root@mcroce-redhat:/home/mcroce# hexdump -n3 -e '1/1 "%0x2"' /dev/urandom >/proc/sys/kernel/hostname
root@mcroce-redhat:/home/mcroce# exec bash
root@5d2e52852:/home/mcroce# hostname
5d2e52852
root@5d2e52852:/home/mcroce# exit
mcroce@mcroce-redhat:~$ hostname
mcroce-redhat