CentOS 7 USB kickstart installation

centos7-customer-installer.sh

#! /bin/bash
# Make a CentOS 7 DVD installer on a USB drive that offers the option
# of doing an automated install via a kickstart file (given by $url
# below).

set -eu

url="http://tftpboot:8000/kickstart/box.cfg"

##### WARNING: make sure this is correct:
usb="/dev/disk/by-id/usb-_Patriot_Memory_0701412932122412-0:0"

iso="/tftpboot/ISO/CentOS/CentOS-7-x86_64-DVD-1503-01.iso"
tmp="/backup/tmp/centos7-respin"
mnt="/mnt/centos7iso"

if [ ! -e "$usb" ]; then
    echo USB drive $usb
    echo does not exist
    exit 1
fi

set -x

mkdir -p $mnt

rm -fr $tmp
mkdir -p $tmp/CentOS-7-unpacked
mkdir -p $tmp/CentOS-7-KS-iso

function cleanup {
    if mount | grep -q "$mnt"; then
	umount $mnt
    fi
}

trap cleanup 0

# put in a list so we can edit this script while it's being executed
{
    mount -o loop $iso $mnt
    rsync -aq $mnt/ $tmp/CentOS-7-unpacked
    umount $mnt

    set +x
    cat <<EOF
Now add something like the following lines to
$tmp/CentOS-7-unpacked/isolinux/isolinux.cfg:

label linuxks
  menu label ^Install CentOS 7 with Kickstart
  append ... ks=$url
  inst.repo=http://tftpboot:8000/centos/7/os/x86_64/
EOF
    echo -n "Hit ENTER when done:"
    read answer
    set -x

    newiso=$tmp/CentOS-7-KS-iso/CentOS-7.0-KS-x86_64-DVD.iso

    # NOTE: the -volid needs to match the isolinux.cfg LABEL= value
    genisoimage -untranslated-filenames \
	-volid 'CentOS 7 x86_64' -J -joliet-long -rational-rock \
	-translation-table -input-charset utf-8 \
	-x ./lost+found \
	-b isolinux/isolinux.bin -c isolinux/boot.cat \
	-no-emul-boot -boot-load-size 4 -boot-info-table \
	-eltorito-alt-boot -e images/efiboot.img -no-emul-boot \
	-T -o $newiso $tmp/CentOS-7-unpacked/

    isohybrid -u $newiso

    # bs=4M seems to be much faster than no bs at all
    time dd bs=4M if=$newiso of=$usb

    udisks --detach $usb

    exit 0
}