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