sudo systemd-nspawn -b -D debian_master

sudo bash -c "echo 1 > /proc/sys/net/ipv4/ip_forward"
sudo systemd-nspawn -b -D ./debian_master -n -p 23:22

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: host0@if6: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 72:ba:f6:a1:ca:f0 brd ff:ff:ff:ff:ff:ff link-netnsid 0

sudo debootstrap stable debian_master http://deb.debian.org/debian/

sudo systemd-nspawn -D debian_master
passwd
logout

sudo systemd-nspawn -b -D debian_master -n -p 22:23