make_iso.sh

#!/usr/bin/env sh
# Automatically add the company custom kickstart file to a UEFI CD Image
#
# Based on notes from:
#  - http://www.tuxfixer.com/mount-modify-edit-repack-create-uefi-iso-including-kickstart-file/
#  - https://github.com/CentOS/Community-Kickstarts
#  - https://fedoraproject.org/wiki/User:Pjones/BootableCDsForBIOSAndUEFI
#
# Halt on any error in the script.
set -e
# Halt on any undefined variable.
set -u

# UEFI notes:
#  When to use gpt vs bios:
#    https://www.redhat.com/archives/kickstart-list/2012-August/msg00005.html
#
# TODO/FIX:
#  done: Add disk info to confirmation screen #1
#  done: Check the provided netmask is valid #2
#  done: Remove the "quiet" option during custom install boot #3
#  done: Boot timeout #4
#  done: Add serial number to ISO name and a text file in /root #5
#  n/a: Fix the isolinux.cfg, adding in a new "label linux" --> "label custom", change default.
#  n/a: Fix duplicate install menu options in isolinux.cfg
#  n/a: Ensure rsync is mirroring to delete extra/modified files.
#  UEFIfix: Bootlocal after timeout
#  UEFIfix: Keep legacy install option (remove check&install)
#  UEFIfix: "failed to find a suitable stage1 device" - part /boot/efi --fstype vfat --size=200 --ondisk=sda

#################################
# Global variables to tweak.
#
# Location to build IOS in - needs about 8GB per ISO type (4GB for files, 4GB for ISO).
BUILDROOT=./tmp
# Source of the RHEL ISOs - this can be a directory with symlinks.
GOLDENISO=./isos

# Timestamp for the image:
TS=$(date +%Y%m%d_%H%M%S)

#################################
# Set the environment variable DEBUG=1 to pause build.
set +u
if [ ! -z "${DEBUG}" ] ; then
  echo "DEBUG mode enabled."
else
  DEBUG=0
fi
set -u

#################################
# Ensure root permissions
if [ `id -u` -gt 0 ] ; then
  echo Must run as root...
  sudo DEBUG="${DEBUG}" $0 $*
  exit
fi

#################################
# Code to catch an exit and cleanup temp files.
#
function clean_exit {
  echo "Exiting using exit function."
  set +u
  if [ ! -z "${BUILDDIR}" ] ; then
    echo "Cleaning up ${BUILDDIR}"
    umount ${BUILDDIR}/isomount/
    rmdir ${BUILDDIR}/isomount/
    rm -rf ${BUILDDIR}/
  fi
  set -u
}
trap clean_exit EXIT

#################################
# Show user the possible ISO files to use
if [ $(ls -1 ${GOLDENISO}/ | wc -l) -le 0 ] ; then
  echo "No files found in the ISO source directory, exiting."
  exit 1
fi

echo "List of available ISOs"
ls -1 ${GOLDENISO}/ | egrep -i iso$ | cat -n
ISONAME="bogus"
set +u
if [ ! -z "$1" ] ; then
  ISONAME="$1"
  echo "Using command line ISO: ${ISONAME}"
fi
set -u

while [ ! -e "${GOLDENISO}/${ISONAME}" ] ; do
  read -p "Please enter the full name of the ISO to use: " -i "${ISONAME}" ISONAME
  if [ ! -e "${GOLDENISO}/${ISONAME}" ] ; then
    echo "Invalid ISO name.  Try again."
  fi
done

ISONAME=$(basename "${ISONAME}" .iso)

if [ ! -e ./media_info/${ISONAME}.info.sh ] ; then
  echo "Missing media info file: ./media_info/${ISONAME}.info.sh "
  exit 1
fi

source "./media_info/${ISONAME}.info.sh"

if [ -z "${KSNAME}" ] ; then
  echo "Missing name of kickstart file to use."
  exit 1
fi

# Setup the location to hold temporary files and build the ISO.
BUILDDIR="${BUILDROOT}/${ISONAME}_tempdir"

# Ensure temporary directories exist.
mkdir -p ${BUILDDIR}/
mkdir -p ${BUILDDIR}/isomount/
mkdir -p ${BUILDDIR}/image/

# Mount the ISO
mount -o loop ${GOLDENISO}/${ISONAME}.iso ${BUILDDIR}/isomount/

# Cleanup from past tests
rm -f ${BUILDDIR}/${MBR_MENUFILE}* ${BUILDDIR}/image/ks.cfg* ${BUILDDIR}/${UEFI_MENUFILE}*

# Copy contents of ISO to new working directory
echo "Copying contents from ISO to ${BUILDDIR}/image/"
rsync -a -q --delete ${BUILDDIR}/isomount/ ${BUILDDIR}/image/

# Copy the kickstart file into the ISO directory
rsync -a ./ksfiles/${KSNAME} ${BUILDDIR}/image/ks.cfg

#ls -altr ${BUILDDIR}/${MBR_MENUFILE}* ${BUILDDIR}/image/ks.cfg* ${BUILDDIR}/${UEFI_MENUFILE}*
#read -p "Pausing after copy, press return to continue." foo

# Search alternative using awk:
#   https://unix.stackexchange.com/a/188269/56732
# awk 'NR==1,/find_this/{sub(/find_this/, "replace_this")} 1' file.to.modify
if [ ${DO_UEFI} -ge 1 ] ; then
  #################################
  # Setup the EFI portion of the boot files (modern systems)
  #
  # Edit the grub.conf in the ../EFI/BOOT/ directory:
  # 1: Change the menuentry title of the first entry:
  echo "===== Setting up UEFI boot options ====="
  local_TS=$(date +%s)
  cp -p ${BUILDDIR}/${UEFI_MENUFILE} ${BUILDDIR}/${UEFI_MENUFILE}.${local_TS}
  awk -v sb="${UEFI_MENU}" "/${UEFI_START}/,/${UEFI_END}/ { if ( \$0 ~ /${UEFI_START}/ ) print sb; next } 1" "${BUILDDIR}/${UEFI_MENUFILE}.${local_TS}" > "${BUILDDIR}/${UEFI_MENUFILE}"
  sleep 1

  # 2: Insert new text:
  INJECT=$(echo "${UEFI_MENU}" | sed ':a;N;$!ba;s/\n/\\n/g')
  sed -i.$(date +%s) "s#ABCDEFGHIJ#${INJECT}#" ${BUILDDIR}/image/EFI/BOOT/grub.cfg
  sleep 1

  # 3: Set default boot to the first one we setup:
  sed -i.$(date +%s) 's/^set default=.../set default="0"/' ${BUILDDIR}/image/EFI/BOOT/grub.cfg
  sleep 1

  # 4: Remove the quiet boot flag
  sed -i.$(date +%s) 's/ quiet//' ${BUILDDIR}/image/EFI/BOOT/grub.cfg

  # 5: Adjust boot delay to 1,000 seconds (~16 minutes)
  sed -i.$(date +%s) 's/set timeout=60/set timeout=1000/' ${BUILDDIR}/image/EFI/BOOT/grub.cfg

  echo "Updated: ${BUILDDIR}/image/EFI/BOOT/grub.cfg"
fi

if [ ${DO_MBR} -ge 1 ] ; then
  #################################
  # Setup the legacy portion of the boot files
  #
  echo "===== Setting up legacy/MBR boot options ====="
  # 1: Remove default boot setting:
  sed -i.$(date +%s) '/\s*menu default/d' ${BUILDDIR}/${MBR_MENUFILE}
  sleep 1

  # 2: Edit the isolinux.cfg to use the new kickstart file.
  local_TS=$(date +%s)
  cp -p ${BUILDDIR}/${MBR_MENUFILE} ${BUILDDIR}/${MBR_MENUFILE}.${local_TS}
  awk -v sb="${MBR_MENU}" "/${MBR_START}/,/${MBR_END}/ { if ( \$0 ~ /${MBR_START}/ ) print sb; next } 1" "${BUILDDIR}/${MBR_MENUFILE}.${local_TS}" > "${BUILDDIR}/${MBR_MENUFILE}"
  sleep 1

  # 2: Remove the quiet boot flag
  sed -i.$(date +%s) 's/ quiet//' ${BUILDDIR}/${MBR_MENUFILE}

  # 3: Adjust boot delay to 1,000 seconds (~16 minutes)
  sed -i.$(date +%s) 's/timeout 600/timeout 10000/' ${BUILDDIR}/${MBR_MENUFILE}

  echo "Updated: ${BUILDDIR}/${MBR_MENUFILE}"
fi

if [ "${DEBUG}" -gt 0 ] ; then
  read -p "Press return to continue building ISO." foo
fi

rm -f ${BUILDDIR}/image/iso_build_date.txt
echo "ISO build date: $(date +'%Y-%m-%d.%H:%M:%S')" >> ${BUILDDIR}/image/iso_build_date.txt
echo "Git repo hash: $(git describe --abbrev=7 --dirty --always --tags)" >> ${BUILDDIR}/image/iso_build_date.txt

#################################
# Now build the ISO image
echo "Executing the \"mkisofs\" command."
mkisofs -U  -A "${CDLABEL}" -V "${CDLABEL}" -volset "${CDLABEL}" -J  -joliet-long -r -v -T \
    -o ${BUILDDIR}/../custom-${ISONAME}.${TS}.iso -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 \
    ${BUILDDIR}/image/ 2>&1 | egrep -v 'estimate finish|^Using\ .*for\ |^Done with:|^Writing:|^Scanning |^Excluded: ..*TRANS.TBL$'

pushd ${BUILDROOT}/
rm -f custom-${ISONAME}.iso.sha256sum custom-${ISONAME}.iso
ln -s custom-${ISONAME}.${TS}.iso custom-${ISONAME}.iso
ln -s custom-${ISONAME}.${TS}.iso.sha256sum custom-${ISONAME}.iso.sha256sum
echo "Execution of \"mkisofs\" complete, computing sha256sum."
sha256sum  custom-${ISONAME}.${TS}.iso > custom-${ISONAME}.${TS}.iso.sha256sum
popd
echo ""
echo "Built ISO available here:"
echo "${BUILDROOT}/custom-${ISONAME}.${TS}.iso"
echo "${BUILDROOT}/custom-${ISONAME}.iso"
ls -al ${BUILDROOT}/custom-${ISONAME}.${TS}.iso*
ls -al ${BUILDROOT}/custom-${ISONAME}.iso