Comment 8 for bug 1427160

Preseed file taken from MAAS "View preseed" UI:

# MAAS - Ubuntu Server Installation
# * Minimal install
# * Cloud-init for bare-metal
# * Cloud-init preseed data

# Locale
d-i debian-installer/locale string en_US.UTF-8

# No splash
d-i debian-installer/splash boolean false

# Keyboard layout
d-i console-setup/ask_detect boolean false
d-i console-setup/layoutcode string us
d-i console-setup/variantcode string

# Network configuration
d-i netcfg/get_nameservers string
d-i netcfg/get_ipaddress string
d-i netcfg/get_netmask string 255.255.255.0
d-i netcfg/get_gateway string
d-i netcfg/confirm_static boolean true

# Local clock (set to UTC and use ntp)
d-i clock-setup/utc boolean true
d-i clock-setup/ntp boolean true
d-i clock-setup/ntp-server string ntp.ubuntu.com
d-i time/zone string Etc/UTC

# Partitioning
d-i partman/early_command string debconf-set partman-auto/disk `list-devices disk | head -n1`
d-i partman-iscsi/mainmenu string finish
d-i partman-auto/method string regular
d-i partman-lvm/device_remove_lvm boolean true
d-i partman-lvm/confirm boolean true
d-i partman-md/device_remove_md boolean true
d-i partman/confirm_write_new_label boolean true
d-i partman/choose_partition select Finish partitioning and write changes to disk
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true
d-i partman/default_filesystem string ext4

# Enable this if you want to override to a specific kernel, such as
# linux-generic-lts-saucy, but Debian Installer should pick the right one based
# on the boot kernel.
#d-i base-installer/kernel/image string linux-server

# User Setup
d-i passwd/root-login boolean false
d-i passwd/make-user boolean true
d-i passwd/user-fullname string ubuntu
d-i passwd/username string ubuntu
d-i passwd/user-password-crypted password !
d-i passwd/user-uid string
d-i user-setup/allow-password-weak boolean false
d-i user-setup/encrypt-home boolean false
d-i passwd/user-default-groups string adm cdrom dialout lpadmin plugdev sambashare

# APT
d-i mirror/country string manual
d-i mirror/http/hostname string za.archive.ubuntu.com
d-i mirror/http/directory string /ubuntu
d-i mirror/http/proxy string http://maas-ip:8000/

# By default the installer requires that repositories be authenticated
# using a known gpg key. This setting can be used to disable that
# authentication. Warning: Insecure, not recommended.
d-i debian-installer/allow_unauthenticated string false

# Lang
d-i pkgsel/language-packs multiselect en
d-i pkgsel/update-policy select none
d-i pkgsel/updatedb boolean true

# Boot-loader
d-i grub-installer/skip boolean false
d-i lilo-installer/skip boolean false
d-i grub-installer/only_debian boolean true
d-i grub-installer/with_other_os boolean true
d-i finish-install/keep-consoles boolean false
d-i finish-install/reboot_in_progress note

# Eject cdrom
d-i cdrom-detect/eject boolean true

# Do not halt/poweroff after install
d-i debian-installer/exit/halt boolean false
d-i debian-installer/exit/poweroff boolean false

# maas client packages
d-i pkgsel/include string cloud-init openssh-server python-software-properties vim avahi-daemon server^

# maas preseed
cloud-init cloud-init/datasources multiselect MAAS
cloud-init cloud-init/maas-metadata-url string http://maas-ip/MAAS/metadata/
cloud-init cloud-init/maas-metadata-credentials string oauth_token_key=OAUTH_TOKEN&oauth_token_secret=OAUTH_TOKEN_SECRET&oauth_consumer_key=OAUTH_CONSUMER_TOKEN
cloud-init cloud-init/local-cloud-config string {apt_preserve_sources_list: true, manage_etc_hosts: localhost}\n

# Post scripts.
# Executes late command and disables PXE.
d-i preseed/late_command string true && \
    in-target sh -c 'f=$1; shift; echo $0 > $f && chmod 0440 $f $*' 'ubuntu ALL=(ALL) NOPASSWD: ALL' /etc/sudoers.d/maas && \
    in-target wget --no-proxy "http://maas-ip/MAAS/metadata/latest/by-id/node-NODE-ID/" --post-data "op=netboot_off" -O /dev/null && \
    true