Disk-space consumed: < 500 MB.

0. Run in shell; takes about 5 minutes depending on download speed.

   #!/bin/bash
   SYSR=/var/lib/machines/debian
   sudo mkdir $SYSR
   sudo chown $USER $SYSR; sudo chgrp $USER $SYSR
   sudo debootstrap --include=sudo,dbus,libpam-systemd sid $SYSR http://httpredir.debian.org/debian/

1. Open a shell inside the new container:

   export SYSR=/var/lib/machines/debian
   sudo systemd-nspawn -m sid -D $SYSR
   
See: root@debian prompt.

2. Create another user the usual way:

   root@debian:~# adduser jack
   Adding user `jack' ...

3. Add your user to systemd-journal group:

   root@debian:~# addgroup jack systemd-journal
   Adding user `jack' to group `systemd-journal' ...

4. Exit container with Ctrl-] 3 times in a row.

5. Employ a text editor from localhost to add jack to /etc/sudoers:

   # User privilege specification
   root    ALL=(ALL:ALL) ALL
   jack    ALL=(ALL:ALL) ALL

Also, employ a text editor to change /etc/hostname to differ from that
of your test machine in order to minimize confusion.

6. Now boot the container and login as your new user:

   [alison@localhost ]$ sudo systemd-nspawn -bD $SYSR
   Spawning container debian on /vol/debian.
   Press ^] three times within 1s to kill container.
   Detected virtualization systemd-nspawn.
   Detected architecture x86-64.

   Welcome to Debian GNU/Linux stretch/sid!
   Debian GNU/Linux stretch/sid sid.localhost.com console

   sid login: jack
   Password:

   jack@sid:~$ systemctl status
   ● sid.localhost.com
    State: running
     Jobs: 0 queued
   Failed: 0 units
    Since: Thu 2015-08-27 17:58:03 UTC; 3min 6s ago
   CGroup: /machine.slice/machine-sid.scope
           ├─1 /lib/systemd/systemd
           └─system.slice
             ├─dbus.service
             │ └─58 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation
             ├─cron.service
             │ └─57 /usr/sbin/cron -f
             ├─systemd-journald.service
             │ └─17 /lib/systemd/systemd-journald
             ├─systemd-logind.service
             │ └─56 /lib/systemd/systemd-logind
             ├─console-getty.service
             │ ├─62 /bin/login --
             │ ├─69 -bash
             │ ├─86 systemctl status
             │ └─87 pager
             └─rsyslog.service
               └─60 /usr/sbin/rsyslogd -n

   jack@sid:~$ sudo dpkg -l "*systemd*"
   sudo: unable to resolve host sid.localhost.com
   [sudo] password for jack:
   Desired=Unknown/Install/Remove/Purge/Hold
   | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
   |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
   ||/ Name                  Version         Architecture    Description
   +++-=====================-===============-===============-================================================
   ii  libpam-systemd        <none>          <none>          (no description available)
   ii  libsystemd0:amd64     224-2           amd64           systemd utility library
   ii  systemd               224-2           amd64           system and service manager
   un  systemd-container     <none>          <none>          (no description available)
   un  systemd-shim          <none>          <none>          (no description available)
   ii  systemd-sysv          224-2           amd64           system and service manager - SysV links
   un  systemd-ui            <none>          <none>          (no description available)

   jack@sid:~$ systemctl --version
   systemd 224
   +PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT -GNUTLS +ACL +XZ -LZ4 +SECCOMP +BLKID -ELFUTILS +KMOD -IDN


7. View/control container from localhost:

   [alison@localhost systemd_tutorial]$ machinectl
   MACHINE CLASS     SERVICE
   sid     container nspawn
   1 machines listed.

   [alison@bonnet systemd_tutorial]$ sudo machinectl list-images
   NAME   TYPE      RO  USAGE CREATED MODIFIED
   debian directory no  n/a   n/a     n/a
   1 images listed.


8. Now you're ready for testing systemd.

   jack@sid:~$ sudo systemctl poweroff

More information:
systemd-nspawn man page
http://www.freedesktop.org/software/systemd/man/systemd-nspawn.html

machinectl man page
http://www.freedesktop.org/software/systemd/man/machinectl.html