Modifying the Init Image

Modifying the Boot Image
If you wish to modify the way that the pxe/tftp works files in the /tftpboot directory can be edited.

Using scripts
Modifying the boot image is easy to do. FOG comes with a script that enables you to easily modify the init image.

The script mounts the image and decompress it so you can view its files to modify them, however it tries to open nautilus to show you the files. Bear in mind that if you have no GUI (or your connected via ssh) you will have to browse the files manually in

/tmp/tmpMnt/

To run the script execute the file in here

/opt/fog/utils/Boot Image Editor/FOGMountBootImage.sh

That will execute the script, when your done modifying the Init image hit Enter and the file will be re compress and set ready to use.

By Hand
Or, to do it by hand:

Version 0.32 and below
cd /tftpboot/fog/images gunzip init.gz mkdir initmountdir mount -o loop init initmountdir

After you're done making changes, you have to clean up and unmount the init image: cd /tftpboot/fog/images umount initmountdir/ rmdir initmountdir gzip init

Version 1.0.0 and up
cd /var/www/{html,}/fog/service/ipxe/ xz -d init{,_32}.xz mkdir initmountdir mount -o loop init{,_32} initmountdir

After you're done making changes, you have to clean up and unmount the init image: cd /var/www/{html,}/fog/service/ipxe/ umount initmountdir rmdir initmountdir xz -C crc32 -9 init{,_32}

Adding sfdisk to the /sbin directory
This will add the sfdisk program into the boot environment: cd /tftpboot/fog/images gunzip init.gz mkdir initmountdir mount -o loop init initmountdir init is now ready for modification. Make your changes: cp /sbin/sfdisk /tftpboot/fog/images/initmountdir/sbin Modifications Complete. Unmount and re-gzip it: umount initmountdir rmdir initmountdir gzip init Now you can use the sfdisk program from the PXE environment.

Remove Authentication from Quick Image
This example will show how to automatically authenticate users when they select Quick Image. If you are happy to allow anybody to deploy an image to a hardrive this is for you. cd /tftpboot/fog/images gunzip init.gz mkdir initmountdir mount -o loop init initmountdir cd /tftpboot/fog/images/initmountdir/bin/ Edit fog.quickimage Comment out the followig lines by putting a # in front
 * 1) echo " Enter a valid FOG username and password.";
 * 2) echo "";
 * 3) echo -n "     Username: ";
 * 4) read username;
 * 5) echo ""
 * 6) echo -n "     Password: ";
 * 7) stty -echo
 * 8) read password;
 * 9) stty echo;
 * 10) echo "";
 * 11) echo ""

Replace with: username="a valid username" password="a valid password"; Save the modification cd ../.. umount initmountdir/ rmdir initmountdir gzip init

You are done and now users can image without the need for a username and a password.