Converts a BOSH Stemcell (Default QCow2) into RAW for use with OpenStack

convert-stemcell.sh

#!/bin/bash

# Dirty script to take a CloudFoundry BOSH stemcell and convert to RAW and repackage (default in QCOW2)
# Matt Johnson <[email protected]>


# Set some vars
MINPARAMS=1
WORKDIR=`date | sha1sum | awk '{print $1}'`

# Check we're being used correctly
if [ $# -lt "$MINPARAMS" ]
then
    echo "Need a minimum of one!"
    echo "----------------------------------------------------"
    echo "Usage:"
    echo "$0 <PATH TO source-stemcell.tgz>"
    echo "----------------------------------------------------"
    exit
fi

# If we dont source the openstackRC none of the openstack CLI commands will login
echo "Installing qemu-tools"
apt-get install -y qemu-utils

echo "Checking for qemu-img"
command -v qemu-img >/dev/null 2>&1 || { echo "Cannot run qemu-img. Exiting " >&2; exit 1; }
echo ".... Good"

# Create Environment
echo "Creating work dir.."
mkdir ${WORKDIR}
cd ${WORKDIR} && WORKPATH=`pwd`
echo "We will work in: $WORKPATH "

# Unpack Stemcell
echo "Unpacking Stemcell"
tar -xzvf $1 -C $WORKPATH
ORIGSHA=`sha1sum ${WORKPATH}/image | awk '{print $1}'`
echo "Original SHA1 of compressed image: $ORIGSHA "

# Unpack root image
echo "Unpacking Root Image"
tar -xzvf $WORKPATH/image -C $WORKPATH && rm $WORKPATH/image

# Convert
echo "Converting root image to RAW"
qemu-img convert -f qcow2 -O raw $WORKPATH/root.img $WORKPATH/root.img.raw && rm $WORKPATH/root.img && mv $WORKPATH/root.img.raw $WORKPATH/root.img

# Compress converted image
echo "Re-Compressing root Image"
cd $WORKPATH && tar -czvf image root.img

# Get SHA1 of new image
NEWSHA=`sha1sum ${WORKPATH}/image | awk '{print $1}'`

echo "New SHA for our root image is: $NEWSHA old SHA was: $ORIGSHA"

# Modify stemcell manifest
echo "Changing SHA in stemcell manifest"
sed -e s/$ORIGSHA/$NEWSHA/g $WORKPATH/stemcell.MF > $WORKPATH/tmp.MF && mv $WORKPATH/tmp.MF $WORKPATH/stemcell.MF

# Change Stemcell name in manifest and disk format
echo "Editing other Stemcell Manifest Metadata"
sed -e s/qcow2/raw/g $WORKPATH/stemcell.MF > $WORKPATH/tmp.MF && mv $WORKPATH/tmp.MF $WORKPATH/stemcell.MF
STEMNAME=`grep name "$WORKPATH/stemcell.MF" | head -n 1 | awk '{print $2}' `
NEWSTEMNAME=$STEMNAME-ft
sed -e s/$STEMNAME/$NEWSTEMNAME/g $WORKPATH/stemcell.MF > $WORKPATH/tmp.MF && mv $WORKPATH/tmp.MF $WORKPATH/stemcell.MF
NEWFILENAME="bosh-stemcell-`grep version stemcell.MF | head -n 1 | awk -F"'" '{print $2}'`-` echo "bosh-openstack-kvm-ubuntu" | awk -F"bosh-" '{print $2}'`-ft"

echo "Our NEW Manifest:"
cat $WORKPATH/stemcell.MF

echo "Repacking..."
cd $WORKPATH && tar -czvf $NEWFILENAME.tgz apply_spec.yml stemcell.MF image

echo "Done. New file should be: $WORKPATH/$NEWFILENAME.tgz"
file $WORKPATH/$NEWFILENAME.tgz