debian-img-burner.sh

# Image burner program to generate debian images for qemu-kvm

#!/bin/bash -x

SRC_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
. $SRC_DIR/config.sh

##############################################################################
DISK_MNT=/mnt/qemu-disk
export http_proxy=$HTTP_PROXY
export https_proxy=$HTTPS_PROXY
export ftp_proxy=$FTP_PROXY
CHROOT_SCRIPT=chroot-run.sh
##############################################################################

function install_prereq {
    apt-get install -y debootstrap qemu-system qemu-kvm qemu-utils gdisk
}

# Clean up function to clear out system state.
function cleanup() {
    umount $DISK_MNT/proc
    umount $DISK_MNT/sys
    umount $DISK_MNT/dev
    umount $DISK_MNT
    umount /dev/nbd0p2
    qemu-nbd -d /dev/nbd0
    #rm -rf $QEMU_IMG_NAME
}

# Pass the error code, exit-state and error string to the function.
# $1 : return error code.
# $2 : exit state, exit the program if error is critical.
# #3 : error string to print.
# 
function exit_on_error() {
    ret_code=$1
    is_exit=$2
    err_str=$3
    if [ $ret_code -ne 0 ]; then
        echo "** $err_str **"
    fi
    if [ $ret_code -ne 0 ] && [ $is_exit -ne 0 ]; then
        echo "** EXITING THE PROGRAM ERR: $ret_code **"
        cleanup
        exit $ret_code
    fi
}

function fdisk_part {
fdisk /dev/nbd0 << EEOF
I
$gpt

p
w

EEOF
}

# Setting the proxy inside the VM apt.
function set_apt_proxy() {
    if [[ -v HTTP_PROXY ]]; then
        proxy_setup="Acquire::http::Proxy \"$HTTP_PROXY\";"
        echo $proxy_setup >  $DISK_MNT/etc/apt/apt.conf
    fi
}

# Create a script file to run commands inside the chroot.
function chroot_script() {
set_apt_proxy
APT_INSTALL_APPS="$(echo -e "${IMG_APPS}" | tr -d '[:space:]')"
APT_INSTALL_APPS=${APT_INSTALL_APPS//,/ }
cat >$DISK_MNT/$CHROOT_SCRIPT <<EOL

#!/bin/bash -x

mount -t proc none /proc

mount -t sysfs none /sys

export PATH=$PATH:/usr/bin:/usr/sbin/

export http_proxy=${HTTP_PROXY}
export https_proxy=${HTTPS_PROXY}
export ftp_proxy=${FTP_PROXY}

#Make apt install non interactive
export DEBIAN_FRONTEND=noninteractive

apt-get install -y grub-pc grub-common

apt-get -f install -y

grub-install --force /dev/nbd0 --modules="biosdisk part_msdos"


apt-get install -y sed

# Update the grub command line options.
sed -i '/GRUB_CMDLINE_LINUX_DEFAULT/d' /etc/default/grub
echo 'GRUB_CMDLINE_LINUX_DEFAULT="nomodeset net.ifnames=1 biosdevname=0"' >> /etc/default/grub

update-grub

echo "Updating root password"

echo "${ROOT_PWD}\n${ROOT_PWD}" | passwd root

#Add a new user for the ssh log-in support.
adduser sugesh --gecos "Sugesh Chandran,2017,1234567890,1234567890" --disabled-password

echo "${ROOT_PWD}\n${ROOT_PWD}" | passwd sugesh

#setup the hostname
echo 'sugesh-vm' > /etc/hostname
sed -i '/127.0.0.1/d' /etc/hosts
echo "127.0.0.1\tlocalhost sugesh-vm" >> /etc/hosts

# Install custom image apps.
apt-get install -y ${APT_INSTALL_APPS}

umount /proc/ /sys/ /dev/

EOL

}

function chroot_setup() {
    mount --bind /dev/ $DISK_MNT/dev
    exit_on_error $? 1 "Failed to mount dev"
    chroot_script
    chmod a+rwx $DISK_MNT/$CHROOT_SCRIPT
    LANG=C chroot $DISK_MNT ./$CHROOT_SCRIPT

    umount $DISK_MNT/dev
}

# Function to update VM grub with disk entry.
function update_vm_grubcfg() {
    sed -i -e 's/nbd0p2/sda2/g' $DISK_MNT/boot/grub/grub.cfg
    exit_on_error $? 1 "ERR: Failed to update grub,"
}

# Function to update fstab with right disk entries.
function set_fstab() {
cat >$DISK_MNT/etc/fstab <<EOL
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda2 during installation
/dev/sda2 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda1 during installation
/dev/sda1 none            swap    sw              0       0

EOL
}

#Function to create apt source list.
function setup_apt_src() {
	rm -rf $DISK_MNT/etc/apt/sources.list.d/*
cat >$DISK_MNT/etc/apt/sources.list <<EOL

deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE} main restricted
deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE}-updates main restricted

deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE} universe
deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE}-updates universe

deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE} multiverse
deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE}-updates multiverse

deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE}-backports main restricted universe multiverse


deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE}-security main restricted
deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE}-security universe
deb http://archive.ubuntu.com/ubuntu ${IMG_SUITE}-security multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu ${IMG_SUITE} partner
# deb-src http://archive.canonical.com/ubuntu ${IMG_SUITE} partne

EOL
}

# Create the static network configuration file.
function set_network() {
cat >$DISK_MNT/etc/network/interfaces <<EOL
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto ens3
iface ens3 inet dhcp
#address 20.0.0.2
#netmask 255.255.254.0

EOL

#Bionic beaver is now using systemd, netplan for networking so set it up
mkdir -p $DISK_MNT/etc/netplan

cat >$DISK_MNT/etc/netplan/config.yaml <<EOL
network:
        version: 2
        renderer: NetworkManager
EOL
}

# function to attach the image to nbd and format it.
function nbd_attach_format_install {
    modprobe nbd max_part=32
    qemu-nbd -c /dev/nbd0 $QEMU_IMG_NAME
    exit_on_error $? 1 "ERR: Failed to init nbd, cannot create image"
    fdisk_part
    exit_on_error $? 1 "ERR: Failed to do partition"
    mkswap /dev/nbd0p1
    exit_on_error $? 1 "ERR: Failed to create swap partition"
    mkfs.ext3 /dev/nbd0p2
    exit_on_error $? 1 "ERR: Failed to format partition"
    mkdir -p $DISK_MNT
    mount /dev/nbd0p2 $DISK_MNT
    exit_on_error $? 1 "ERR: Failed to mount disk,"
    debootstrap --include=$IMG_KERNEL_APPS,$DEFAULT_IMG_APPS \
    $IMG_SUITE $DISK_MNT $IMG_MIRROR_URL
}

function create_qcow_disk {
    # XXX :: validate the input before using the file name.
    case $QCOW_SIZE in
        10)
        QCOW_SIZE='10G'
        gpt='10G-ubuntu-gpt-disk'
        ;;
        15)
        QCOW_SIZE='15G'
        gpt='15G-ubuntu-gpt-disk'
        ;;
        20)
        QCOW_SIZE='20G'
        gpt='20G-ubuntu-gpt-disk'
        ;;
        200)
        QCOW_SIZE='200G'
        gpt='200G-ubuntu-gpt-disk'
        ;;
        500)
        QCOW_SIZE='500G'
        gpt='500G-ubuntu-gpt-disk'
        ;;
        *)
        QCOW_SIZE=10G
        gpt='10G-ubuntu-gpt-disk'
        ;;
    esac
    echo "Creating the disk of size $QCOW_SIZE and diskfile $gpt"
    rm -rf $QEMU_IMG_NAME
    qemu-img create -f qcow2 $QEMU_IMG_NAME $QCOW_SIZE
    exit_on_error $? 1 "ERR:Failed to create qemu-img"

}

function main {
    install_prereq
    cleanup
    create_qcow_disk
    nbd_attach_format_install
    chroot_setup
    update_vm_grubcfg
    set_fstab
    set_network
    setup_apt_src
    cleanup
}

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