mkcustiso.rb

#!/usr/bin/env ruby
require 'optparse'
require 'pathname'
require 'tmpdir'

$options = {}

opt = OptionParser.new
opt.on('--iso ISOFILE',         'base iso image name')  {|v| $options[:iso] = v }
opt.on('--out OUTFILE',         'output file name')     {|v| $options[:out] = v }
opt.on('--preseed PRESEEDFILE', 'preseed config file')  {|v| $options[:seed] = v }

opt.parse!(ARGV)

if $options[:iso] == nil || $options[:out] == nil || $options[:seed] == nil
  puts opt
  abort
end

def docmd(cmd)
  puts cmd
  system(cmd)
end

def set_isolinux_cfg(isodir)
  open("#{isodir}/isolinux/isolinux.cfg", 'w') do |io|
    io.print(<<"EOS")
# D-I config version 2.0
default install
label install
  menu label ^Install Ubuntu Server
  kernel /install/vmlinuz
  append auto=true pkgsel/language-pack-patterns= pkgsel/install-language-support=false vga=normal file=/cdrom/preseed/#{File.basename($options[:seed])} initrd=/install/initrd.gz quiet --
label hd
  menu label ^Boot from first hard disk
  localboot 0x80
EOS
  end
end

def set_preseed_cfg(isodir)
  docmd("cp #{$options[:seed]} #{isodir}/preseed")
end

def genisoimage(isodir, outname)
  docmd("genisoimage -N -J -R -D -V 'PRESEED' -o #{outname} -b isolinux/isolinux.bin -c isolinux/isolinux.cat -no-emul-boot -boot-load-size 4 -boot-info-table #{isodir}")
end

Dir.mktmpdir(File.basename($0, '.*')) do |tmpdir|
  isopath = Pathname.new($options[:iso]).realpath

  docmd("cd #{tmpdir}; 7z x #{isopath}")
  docmd("rm -rf #{tmpdir}/[BOOT]")

  set_isolinux_cfg(tmpdir)
  set_preseed_cfg(tmpdir)
  genisoimage(tmpdir, $options[:out])
end