Builds a new Eucalyptus image based on an existing *CentOS* image combined with the contents of running modified instances. Then adds it to the images in Eucalyptus. This is really useful if you want to constantly make changes to your base images. Also includes support for a custome run_once.sh script which will be run on first boot. Please read…

rebase.sh

#!/bin/sh

################# CHANGE THESE! ######################
IMAGE=centos-ops
RAMDISK_IMAGE=eri-A3493391
KERNEL_IMAGE=eki-E7E73878
INSTANCE_KEY=~/credentials/admin/admin.private
. ~/credentials/admin/eucarc
######################################################
if [ -f ${IMAGE}.img ]
then
	echo
else
    echo "Could not find ${IMAGE}.img, this should be your base filesystem image."
    exit -1
fi

if [ -z "$1" ]
then
    echo "Usage: rebase.sh <running-instance-ip> [ <image-flavor> ] "
    exit -1
fi

if [ -z "$2" ]
then
    FLAVOR=default
else
    FLAVOR=$2
fi

BUCKET=${IMAGE}-images
MOUNT_DIR=img-mount
DIR=$(pwd)
IP=$(hostname -i)
TIME=$(date +%F-%H-%M-%S)
FINAL_IMAGE_NAME=${IMAGE}-${FLAVOR}-${TIME}

echo "Simply make sure you have a file called ${IMAGE}.img edit the scripts variables (especially the ramdisk and kernel images), remove the exit -1 line from the script and away you go."
exit -1

mkdir -p $MOUNT_DIR
mkdir tmp
rm -rf tmp/*
cp ${IMAGE}.img tmp/${IMAGE}-${TIME}.img
mount -o loop tmp/${IMAGE}-${TIME}.img $MOUNT_DIR
mkdir -p $MOUNT_DIR/proc
mkdir -p $MOUNT_DIR/sys
mkdir -p $MOUNT_DIR/dev
mount -o bind /proc $MOUNT_DIR/proc
mount -o bind /sys $MOUNT_DIR/sys
mount -o bind /dev $MOUNT_DIR/dev
scp -i  ${INSTANCE_KEY} root@$1:~/.ssh/id_rsa.pub /tmp/remote.pub
if grep "$(cat /tmp/remote.pub)" ~/.ssh/authorized_keys
then
	echo "Remote already has access to local."
else
	cat /tmp/remote.pub >>  ~/.ssh/authorized_keys
fi

ssh -i ${INSTANCE_KEY} root@$1 <<EOF
if [ run_once.log ]
then
    chkconfig runonce on
    rm run_once.log
fi
cd /
 tar -zcvpf /media/ephemeral0/all.tar.gz --preserve-permissions --preserve-order --directory / --exclude=mnt --exclude=proc --exclude=tmp --exclude=dev --exclude=sys --exclude=media  /
 scp /media/ephemeral0/all.tar.gz root@${IP}:${DIR}/tmp
EOF

cd $MOUNT_DIR
cp ../tmp/all.tar.gz .

if [ -f  root/run_once.sh ]
then
    cp root/run_once.sh ../tmp
fi

rm -rf boot etc home lib lib64 opt bin sbin root selinux srv usr var
tar -zxpv --preserve-permissions --same-owner -f all.tar.gz
rm -f all.tar.gz

cat > etc/init.d/runonce << 'EOF'
#!/bin/bash
#
# runonce  run once
#
# chkconfig: 3 98 98
# description: Run on first boot

case "$1" in
  start)
    cd /root
    bash /root/run_once.sh  2>&1 > /root/run_once.log
    chkconfig runonce off
  ;;
  stop|status|restart|reload|force-reload)
    # do nothing
  ;;
esac

EOF

cd etc/rc3.d
ln -s ../init.d/runonce S98runonce
cd -


#Force networking init on next reboot
sed -i 's/HWADDR=".*"//' etc/sysconfig/network-scripts/ifcfg-eth0
rm -f etc/udev/rules.d/70-persistent-net.rules

if [ -f  ../tmp/run_once.sh ]
then
    cp ../tmp/run_once.sh root
fi
cd ..

umount $MOUNT_DIR/proc
umount $MOUNT_DIR/sys
umount $MOUNT_DIR/dev
umount $MOUNT_DIR
rmdir $MOUNT_DIR

MANIFEST_TMP=$(euca-bundle-image -r x86_64 -i $(ls tmp/*.img) --ramdisk ${RAMDISK_IMAGE} --kernel ${KERNEL_IMAGE} | tail -1 | cut -c15-)
MANIFEST_NAME=`echo $(euca-upload-bundle -b ${BUCKET} -m $MANIFEST_TMP | tail -1 | cut -c9-)`
ID=$(euca-register -n ${FINAL_IMAGE_NAME} $MANIFEST_NAME | tail -1 | cut -c7-)
euca-modify-image-attribute -l $ID -a all