#!/bin/sh

#==============================================================================+
# File name   : centoskvm.sh
# Begin       : 2013-04-18
# Last Update : 2013-04-25
# Version     : 1.0.0
#
# Description : Shell script used to generate a CentOS Virtual Machine image.
#
# Website     : https://github.com/fubralimited/CentOS-KVM-Image-Tools
#
# Author: Nicola Asuni
#
# (c) Copyright:
#               Fubra Limited
#               Manor Coach House
#               Church Hill
#               Aldershot
#               Hampshire
#               GU12 4RQ
#               UK
#               http://www.fubra.com
#               support@fubra.com
#
# License:
#    Copyright (C) 2012-2013 Fubra Limited
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero General Public License as
#    published by the Free Software Foundation, either version 3 of the
#    License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
#    See LICENSE.TXT file for more information.
#==============================================================================+

# CONFIGURATION

LIBVIRT_IMAGE_BASE=/data/libvirt

# USAGE EXAMPLE:
# sh centoskvm.sh centos-gold-master

# ensure script is being run as root
if [ `whoami` != root ]; then
   echo "ERROR: This script must be run as root" 1>&2
   exit 1
fi

# check for image name and kickstart file
if [ -z "$1" -o -z "$2" -o -z "$3" ]; then
	echo "ERROR: No argument supplied. Please provide the following parameters:"
	echo "       <image name> [ x86_64 | i386 ] [ 5 | 6 | 7 ] [<kickstart>] [<options>]"
	echo "       being architecture and 5 6 7 being the major Centos version"
	echo "       <kickstart> provide your own optional kickstart file"
	echo "       <options> currently the only option is 'noshrink':"
	echo "          noshrink: don't skrink the image to minimal size after building"
	exit 1
fi

# name of the image
IMGNAME=$1

# architecture
ARCH=$2

# version of Centos
VER=$3

if test "X$4" != "X"; then
	KICKSTART=$4
else
	# compose the name of the kickstart file
	KICKSTART=centos$3-$ARCH-master.cfg
fi

# some sanity checks per architecture and major release
# and set some limits
case ${ARCH}_${VER} in
	i386_5|x86_64_5|i386_6|x86_64_6)
		VM_MEMORY=512
		;;
		
	x86_64_7)
		VM_MEMORY=1024
		;;
	
	i386_7|*)
		echo "Unsupported architecture '$ARCH' and major release '$VER'" 1>&2
		exit 1	
esac

# VM image file extension
EXT="qcow2"

echo "Generating VM ..."

# create image file
virt-install \
--name $IMGNAME \
--ram $VM_MEMORY \
--cpu host \
--vcpus 1 \
--nographics \
--os-type=linux \
--os-variant=rhel$VER \
--location=http://mirror.switch.ch/ftp/mirror/centos/$VER/os/$ARCH \
--initrd-inject=kickstarts/$KICKSTART \
--extra-args="ks=file:/$KICKSTART text console=tty0 utf8 console=ttyS0,115200" \
--disk path=$LIBVIRT_IMAGE_BASE/$IMGNAME.$EXT,size=10,bus=virtio,format=qcow2 \
--force \
--noreboot

# change directory
cd $LIBVIRT_IMAGE_BASE

if test "X$5" != "Xnoshrink"; then

	# reset, unconfigure a virtual machine so clones can be made
	virt-sysprep --no-selinux-relabel -a $IMGNAME.$EXT

	# SELinux: relabelling all filesystem
	#guestfish --selinux -i $IMGNAME.$EXT <<EOF
	#sh load_policy
	#sh 'restorecon -R -v /'
	#EOF
	# fails with:
	#*stdin*:1: libguestfs: error: sh: SELinux:  Could not downgrade policy file /etc/selinux/targeted/policy/policy.24, searching for an older version.
	#SELinux:  Could not open policy file <= /etc/selinux/targeted/policy/policy.24:  No such file or directory
	# really needed?

	# make a virtual machine disk sparse
	TMPDIR=/data/tmp virt-sparsify --compress --convert qcow2 --format qcow2 $IMGNAME.$EXT $IMGNAME-sparsified.$EXT

	# remove original image
	rm -rf $IMGNAME.$EXT

	# rename sparsified
	mv $IMGNAME-sparsified.$EXT $IMGNAME.$EXT

fi

# set correct ownership for the VM image file
#chown qemu:qemu $IMGNAME.$EXT

echo "Process Completed. Use the 'virt start $IMGNAME' command to start the newly created VM."

#==============================================================================+
# END OF FILE
#==============================================================================+