Modifying the Init Image

Modifying the Boot Image

If you wish to modify the way that the pxe/tftp works init files can be edited - run as root to be able to loop mount:

cd ~
cp /var/www/html/fog/service/ipxe/init.xz .
xz -d init.xz
mkdir -p initmountdir
mount -o loop init initmountdir

Now you find the uncompressed content of the initrd in ~/initmountdir and can make adjustments as needed. After you're done making changes, you have to unmount, re-compress and copy back the init image:

cd ~
umount initmountdir
xz -C crc32 -9 init
cp init.xz /var/www/html/fog/service/ipxe/

You want to apply the same changes to the 32-bit init file as well! Follow the same steps outlined above but using the filename init_32.xz instead.

Examples

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

 #echo "  Enter a valid FOG username and password.";
 #echo "";
 #echo -n "      Username: ";
 #read username;
 #echo ""
 #echo -n "      Password: ";
 #stty -echo
 #read password;
 #stty echo;
 #echo "";
 #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.