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Paranoid Penguin - Customizing Linux Live CDs, Part I

Issue 169

From Issue #169
May 2008

May 01, 2008  By Mick Bauer
 in
Make your desktop completely portable with a custom live CD.
Conclusion

You've now got the basic technique for customizing an Ubuntu live CD. Although I didn't go into much depth showing actual customizations beyond removing and adding packages, I'll continue this series next time with detailed guidance on bundling and preconfiguring specific security tools into your live CD.

Until then, have fun experimenting with live CDs, and of course, be safe!

Appendix

Here's the complete procedure, in the form of a raw list of all commands described in this article. The $ prompt indicates commands executed as an unprivileged user, and the # prompt shows commands that are executed by root. 

00-$ dd if=/dev/cdrom of=./ubuntu-7.10-desktop-i386.iso

01-$ mkdir -p ./isomount ./isonew/squashfs ./isonew/cd
↪./isonew/custom

02-$ sudo mount -o loop ./ubuntu-7.10-desktop-i386.iso ./isomount/

03-$ rsync --exclude=/casper/filesystem.squashfs -a ./isomount/
↪./isonew/cd

04-$ sudo modprobe squashfs

05-$ sudo mount -t squashfs -o loop
↪./isomount/casper/filesystem.squashfs ./isonew/squashfs/

06-$ sudo rsync -a ./isonew/squashfs/ ./isonew/custom

07-$ sudo cp /etc/resolv.conf /etc/hosts ./isonew/custom/etc/

08-$ sudo cp /etc/apt/sources.list ./isonew/custom/etc/apt/

09-$ sudo chroot ./isonew/custom

10-# mount -t proc none /proc/

11-# mount -t sysfs none /sys/

12-# export HOME=/root

13-# apt-get remove --purge `dpkg-query -W --showformat='${Package}\n'
↪|grep openoffice`

14-# apt-get remove --purge `dpkg-query -W --showformat='${Package}\n'
↪|grep gimp`

15-# apt-get update

16-# apt-get install tor privoxy

17-# apt-get dist-upgrade

18-# apt-get clean

19-# rm -rf /tmp/*

20-# umount /proc/

21-# umount /sys/

22-# exit

23-$ chmod +w ./isonew/cd/casper/filesystem.manifest

24-$ sudo chroot ./isonew/custom dpkg-query -W --showformat='${Package}
↪${Version}\n' > ./isonew/cd/casper/filesystem.manifest

25-$ sudo cp ./isonew/cd/casper/filesystem.manifest
↪./isonew/cd/casper/filesystem.manifest-desktop

26-$ sudo mksquashfs ./isonew/custom
↪./isonew/cd/casper/filesystem.squashfs

27-$ sudo rm ./isonew/cd/md5sum.txt

28-$ sudo -s

29-# cd ./isonew/cd

30-# find . -type f -print0 | xargs -0 md5sum > md5sum.txt

31-# exit

32-$ cd ./isonew/cd

33-$ sudo mkisofs -r -V "Ubuntu-Live-PrivateSurf" -b
↪isolinux/isolinux.bin -c isolinux/boot.cat -cache-inodes -J -l
↪-no-emul-boot -boot-load-size 4 -boot-info-table -o
↪~/Ubuntu-Live-7.10-PrivateSurf.iso .

Resources

Debuntu.org's “Customize Your Ubuntu Live CD” Tutorial: www.debuntu.org/how-to-customize-your-ubuntu-live-cd

Jeffery Douglas Waddel's “Secure Boot CDs for VPN HOWTO”: www.linux.org/docs/ldp/howto/Secure-BootCD-VPN-HOWTO.html

Daniel Barlow's “Building Your Own Live CD”: www.linuxjournal.com/article/7246

Mick Bauer (darth.elmo@wiremonkeys.org) is Network Security Architect for one of the US's largest banks. He is the author of the O'Reilly book Linux Server Security, 2nd edition (formerly called Building Secure Servers With Linux), an occasional presenter at information security conferences and composer of the “Network Engineering Polka”.

______________________

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From CD ISO to DVD ISO?

kalahari875's picture
Submitted by kalahari875 on Thu, 04/10/2008 - 15:01.

If adding too much software to fit on a CD ISO image, is this approach suitable to simply burning the resulting image on a DVD instead?

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