= Domain Cloning =
Once a template system has been installed, that system can be cloned. `virt-clone` will automatically change the MAC address of your network device.

== Cloning ==
Use the script below to clone your template.

`domain_clone_bullseye.sh`
{{{#!highlight bash
#!/bin/sh

SRC_VOLUME_GROUP="vg_storage"
DST_VOLUME_GROUP="vg_storage"
SRC_NAME="bullseye-template"
SRC_VOLUME="kvm_${SRC_NAME}_vda"
SRC_VOLUME_SIZE=`lvs /dev/${SRC_VOLUME_GROUP}/${SRC_VOLUME} -o LV_SIZE --noheadings --units B --nosuffix`
DST_NAME="bullseye-clone"
DST_VOLUME="kvm_${DST_NAME}_vda"
DST_MEMORY="256M"
MOUNTPOINT="/mnt/domain_root"
MAC=""

if [ ! -e /sbin/kpartx ]
then
	apt-get install -y kpartx
fi

if [ $# -gt 0 ]
then
	DST_NAME=${1}
	DST_VOLUME="kvm_${DST_NAME}_vda"
fi

if [ "${2}" != "" ]
then
	MAC="--mac ${2} "
else
        MAC=$(grep ${DST_NAME} /root/scripts/mac | awk -F "\t" {'print $1'})
        MAC="--mac ${MAC}"
fi

if [ ! -e /dev/${DST_VOLUME_GROUP}/${DST_VOLUME} ]
then
	# create lvm partition
	lvcreate --yes --size ${SRC_VOLUME_SIZE}B --name ${DST_VOLUME} ${DST_VOLUME_GROUP}

	# clone the domain
	virt-clone \
		--original ${SRC_NAME} \
		--name ${DST_NAME} \
		--file /dev/${DST_VOLUME_GROUP}/${DST_VOLUME} \
		${MAC} \
		--check path_in_use=off,path_exists=off

	# mount the domains / partition
	OFFSET=`kpartx /dev/${DST_VOLUME_GROUP}/${DST_VOLUME} | tail -n1|awk {'print $6'}`
	OFFSET_BYTES="$((${OFFSET} * 512))"
	losetup -o ${OFFSET_BYTES} /dev/loop0 /dev/${DST_VOLUME_GROUP}/${DST_VOLUME}
	pvscan
	vgscan
	vgchange -ay vg_os
	if [ ! -e ${MOUNTPOINT} ]
	then
		mkdir -p ${MOUNTPOINT}
	fi
	mount -o subvol=@rootfs /dev/vg_os/root ${MOUNTPOINT}
	# manipulate domain
	mkdir ${MOUNTPOINT}/root/scripts
	cp /root/scripts/guest_cleanup.sh ${MOUNTPOINT}/root/scripts
	# hostname
	cp ${MOUNTPOINT}/etc/hosts ${MOUNTPOINT}/etc/hosts.kk
	sed -i "s/${SRC_NAME}/${DST_NAME}/g" ${MOUNTPOINT}/etc/hosts
	cp ${MOUNTPOINT}/etc/hostname ${MOUNTPOINT}/etc/hostname.kk
	sed -i "s/${SRC_NAME}/${DST_NAME}/g" ${MOUNTPOINT}/etc/hostname

	# rc.local
	echo "#!/bin/sh" > ${MOUNTPOINT}/etc/rc.local
	# this delay is needed for the network to settle, works with 32, but using 64 to be sure
	#echo "sleep 64" >> ${MOUNTPOINT}/etc/rc.local
	echo "/root/scripts/guest_cleanup.sh ${DST_NAME}" >> ${MOUNTPOINT}/etc/rc.local
	echo "rm /etc/rc.local" >> ${MOUNTPOINT}/etc/rc.local
	echo "shutdown -h 0" >> ${MOUNTPOINT}/etc/rc.local
	echo "exit 0" >> ${MOUNTPOINT}/etc/rc.local
	chmod +x ${MOUNTPOINT}/etc/rc.local
	# ssh keys
	mkdir ${MOUNTPOINT}/root/.ssh
	cat /root/scripts/login_id_rsa.pub >> ${MOUNTPOINT}/root/.ssh/authorized_keys
	mkdir ${MOUNTPOINT}/home/kale/.ssh
	cat /root/scripts/login_id_rsa.pub >> ${MOUNTPOINT}/home/kale/.ssh/authorized_keys
	chown -R kale:kale ${MOUNTPOINT}/home/kale/
	# unmount and cleanup
	umount ${MOUNTPOINT}
	vgchange -an vg_os
	losetup -d /dev/loop0
	# cleanup domain
	virt-xml ${DST_NAME} --edit --graphics password=${DST_NAME}
	#virt-xml ${DST_NAME} --remove-device --graphics all
	virsh setmaxmem ${DST_NAME} --size ${DST_MEMORY} --config
	virsh setmem ${DST_NAME} --size ${DST_MEMORY} --config
	virsh start ${DST_NAME}
else
	echo "${0}: refusing to overwrite existing domain"
fi
}}}

=== Cleaning up Guest OS on First Boot ===

Before using this script, notice that the root password is set to the hostname. Please make up your own method for setting the root password. Preferable it should be randomized and ssh keys should be used instead of knowing the password.

`guest_cleanup.sh`
{{{#!highlight bash
#!/bin/sh

NAME=""
if [ $# -gt 0 ]
then
        # the new hostname
        NAME=${1}

        # root password
        echo "root:${NAME}" | chpasswd

        # sshd
        rm /etc/ssh/ssh_host_*
        dpkg-reconfigure openssh-server
        systemctl restart sshd

        # extend filesystem size
        lvextend --size 3G /dev/vg_os/root
        btrfs filesystem resize max /

        # network
        cp /etc/default/grub /etc/default/grub.kk
        sed -i 's/GRUB_CMDLINE_LINUX=""/GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0"/g' /etc/default/grub
        update-grub
        cp /etc/network/interfaces /etc/network/interfaces.kk
        sed -i 's/allow-hotplug enp1s0/allow-hotplug eth0/' /etc/network/interfaces
        sed -i 's/allow-hotplug eth0/#allow-hotplug eth0\nauto eth0/' /etc/network/interfaces
        sed -i 's/iface enp1s0 inet dhcp/iface eth0 inet dhcp/' /etc/network/interfaces

        # cleanup
        rm /root/scripts/guest_cleanup.sh
        rmdir /root/scripts
        shutdown -h 0
else
        echo ${0}: requires a hostname as parameter
fi

}}}

=== A List of Predefined MAC Adresses ===

`mac`
{{{
#<mac><tab><hostname>
# virtual devices for redundant setup
52:54:00:52:de:25       ns01
52:54:00:cf:5c:d3       ns02
52:54:00:65:0f:42       dhcp01
52:54:00:47:84:7d       dhcp02
52:54:00:e0:0f:1d       ntp01
52:54:00:b6:76:ee       ntp02
# virtual devices for maintenance
52:54:00:94:a4:2e       login
}}}

Make a clone.
{{{
./domain_clone_bullseye.sh clone
}}}

== Memory ==
Increase or decrease amount of memory by [[Domain Editing|editing the domain]].

== Network ==
For your convenience add the MAC address to the DHCP servers list of fixed IP-adresses before starting the system for the first time. This way you know beforehand which IP-address to connect to.

== Guest OS ==
Continue by configuring the [[KVM Guest Operating System|KVM Guest Operating System]].