#!/bin/sh
#
#  This script is designed to setup the kernel and ramdisk inside
# the xen-tools configuration file; and also update any stored values
# in any pre-generated Xen guests.
#
#  This is useful if you have upgraded your Xen kernel.
#
# Steve
# --
#




#
#  Find the kernel to use, and the ramdisk, unless they are specified
# in the environment.
#
if [ -z "${kernel}" ]; then
    kernel=`ls -1 /boot| grep ^vm| grep -v syms| grep xen | sort -r| head -n 1`
    kernel="/boot/${kernel}"
fi
if [ -z "${ramdisk}" ]; then
    ramdisk=`ls -1 /boot| grep ^init| grep xen| sort -r| head -n 1`
    ramdisk="/boot/${ramdisk}"
fi


#
#  Abort if we didn't find a kernel / ramdisk
#
if [ -z "${kernel}" ]; then
    echo "Failed to find Xen kernel."
    exit
fi
if [ -z "${ramdisk}" ]; then
    echo "Failed to find Xen ramdisk."
    exit
fi


#
#  Show what we're going to do - and prompt for confirmation.
#
cat <<EOF

  Updating xen-tools configuration file, and all Xen guests with:

    kernel  : ${kernel}
    ramdisk : ${ramdisk}

  Press enter to continue, or Ctrl-c to abort.

EOF
read __dummy



#
#  Update the xen-tools configuration file.
#
perl -pi -e "s|^\s*kernel\s*=(.*)|kernel = ${kernel}|" /etc/xen-tools/xen-tools.conf
perl -pi -e "s|^\s*initrd\s*=(.*)|initrd = ${ramdisk}|" /etc/xen-tools/xen-tools.conf





#
#  Now modify each of the Xen guest configuration files beneath /etc/xen.
#
for i in /etc/xen/*.cfg; do
    
    # test that the file exists - ie. glob succeeded.
    if [ -e $i ]; then
                
        #
        #  Upgrade kernel + ramdisk
        #
        perl -pi -e "s|^\s*kernel\s*=(.*)|kernel = '${kernel}'|" $i
        perl -pi -e "s|^\s*ramdisk\s*=(.*)|ramdisk = '${ramdisk}'|" $i

    fi

done