livecd-rootfs/live-build/ubuntu/hooks/099-ubuntu-image-customization.chroot

#!/bin/bash -ex

. /root/config/chroot

# Specific ubuntu-image chroot configuration goes here.
if [ "$IMAGEFORMAT" == "none" ]; then
    if [ "$SUBPROJECT" == "desktop-preinstalled" ]; then
        # Create files/dirs Ubiquity requires
        mkdir -p /var/log/installer
        touch /var/log/installer/debug
        touch /var/log/syslog
        chown syslog:adm /var/log/syslog

        # Create the oem user account
        /usr/sbin/useradd -d /home/oem -m -N -u 29999 oem

        /usr/sbin/oem-config-prepare --quiet
        touch "/var/lib/oem-config/run"

        # Make the writable partition grow
        echo "LABEL=writable    /     ext4    defaults,x-systemd.growfs    0 0" >>/etc/fstab

        # Create a 1GB swapfile
        dd if=/dev/zero of=/swapfile bs=1M count=1024
        chmod 0600 /swapfile
        mkswap /swapfile

        echo "/swapfile         none  swap    sw    0 0" >>/etc/fstab
    fi
fi