Packer QEMU / KVM example.

build.json

{

    "variables": {
        "ssh_user": "root",
        "ssh_pass": "T@c0_Bu3n0"
    },

    "builders": [

        {
            "type": "qemu",
            "accelerator": "kvm",
            "vm_name": "trusty64",
            "disk_size": 50000,
            "output_directory": "output",

            "headless": true,

            "iso_url": "http://archive.ubuntu.com/ubuntu/dists/trusty-updates/main/installer-amd64/current/images/netboot/mini.iso",
            "iso_checksum": "2988edf35356df844f3028e4aea3bbcff99b127f",
            "iso_checksum_type": "sha1",

            "ssh_username": "{{user `ssh_user`}}",
            "ssh_password": "{{user `ssh_pass`}}",
            "ssh_wait_timeout": "60m",

            "http_directory": "./",

            "boot_command": [
                "<esc><wait>",
                "linux ",
                "preseed/url=http://{{.HTTPIP}}:{{.HTTPPort}}/preseed.cfg ",
                "debian-installer=en_US auto locale=en_US kbd-chooser/method=us ",
                "hostname={{.Name}} ",
                "fb=false debconf/frontend=noninteractive ",
                "keyboard-configuration/modelcode=SKIP keyboard-configuration/layout=USA ",
                "keyboard-configuration/variant=USA console-setup/ask_detect=false ",
                "initrd=initrd.gz --",
                "<enter>"
            ],

            "shutdown_command": "echo '{{user `ssh_pass`}}' | sudo -S shutdown -P now"
        }

    ],

    "provisioners": [

        {
            "type": "shell",
            "inline": "apt-get -y upgrade && apt-get -y dist-upgrade"
        },

        {
            "type": "shell",
            "inline": " apt-get -y autoremove && apt-get -y clean && apt-get -y autoclean"
        }

    ]

}

gistfile1.txt

## Localization
########################################

# Preseeding only locale sets language, country and locale.
d-i debian-installer/locale string en_US

# Keyboard selection.
# Disable automatic (interactive) keymap detection.
d-i console-setup/ask_detect boolean false
d-i keyboard-configuration/layoutcode string us


## Networking
########################################

# netcfg will choose an interface that has link if possible. This makes it
# skip displaying a list if there is more than one interface.
d-i netcfg/choose_interface select auto

# Disable that annoying WEP key dialog.
d-i netcfg/wireless_wep string


## User accounts
########################################

# Enable the root user account
d-i passwd/root-login boolean true

# Set the root user password
d-i passwd/root-password password T@c0_Bu3n0
d-i passwd/root-password-again password T@c0_Bu3n0

# Skip creation of normal user account
d-i passwd/make-user boolean false

# Allow weak password
#d-i user-setup/allow-password-weak boolean true


## Clock and time zone
########################################

# Controls whether or not the hardware clock is set to UTC.
d-i clock-setup/utc boolean true

# You may set this to any valid setting for $TZ; see the contents of
# /usr/share/zoneinfo/ for valid values.
d-i time/zone string UTC

# Controls whether to use NTP to set the clock during the install
d-i clock-setup/ntp boolean true


## Partitioning
########################################

# Alternatively, you may specify a disk to partition. If the system has only
# one disk the installer will default to using that, but otherwise the device
# name must be given in traditional, non-devfs format (so e.g. /dev/hda or
# /dev/sda, and not e.g. /dev/discs/disc0/disc).
# For example, to use the first SCSI/SATA hard disk:
#d-i partman-auto/disk string /dev/sda
# In addition, you'll need to specify the method to use.
# The presently available methods are:
# - regular: use the usual partition types for your architecture
# - lvm:     use LVM to partition the disk
# - crypto:  use LVM within an encrypted partition
d-i partman-auto/method string regular

# If the system has free space you can choose to only partition that space.
# This is only honoured if partman-auto/method (below) is not set.
# Alternatives: custom, some_device, some_device_crypto, some_device_lvm.
d-i partman-auto/init_automatically_partition select biggest_free

# If you just want to change the default filesystem from ext3 to something
# else, you can do that without providing a full recipe.
d-i partman/default_filesystem string ext4

# The full recipe format is documented in the file partman-auto-recipe.txt
# included in the 'debian-installer' package or available from D-I source
# repository. This also documents how to specify settings such as file
# system labels, volume group names and which physical devices to include
# in a volume group.

# This makes partman automatically partition without confirmation, provided
# that you told it what to do using one of the methods above.
d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman/choose_partition select finish
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true


## Mirror settings
########################################

# If you select ftp, the mirror/country string does not need to be set.
d-i mirror/country string manual
d-i mirror/http/hostname string archive.ubuntu.com
d-i mirror/http/directory string /ubuntu
d-i mirror/http/proxy string


## Update policy
########################################

# Policy for applying updates. May be "none" (no automatic updates),
# "unattended-upgrades" (install security updates automatically), or
# "landscape" (manage system with Landscape).
d-i pkgsel/update-policy select none


## Language support
########################################

# Don't download language support
d-i pkgsel/install-language-support boolean false


## Package selection
########################################

tasksel tasksel/first multiselect standard, ubuntu-server, openssh-server

# Individual additional packages to install
d-i pkgsel/include string ntp


## Boot loader installation
########################################

# This is fairly safe to set, it makes grub install automatically to the MBR
# if no other operating system is detected on the machine.
d-i grub-installer/only_debian boolean true

# This one makes grub-installer install to the MBR if it also finds some other
# OS, which is less safe as it might not be able to boot that other OS.
d-i grub-installer/with_other_os boolean true


## Finishing up the installation
########################################

# Avoid that last message about the install being complete.
d-i finish-install/reboot_in_progress note