Glance load - a utility to monitor an ETag and load the corresponding file into glance.

glance_load.sh

#!/usr/bin/env bash
# glance_load.sh
# Brian "Redbeard" Harrington <brian@dead-city.org>
#
# This code is in the public domain.
#
# A tool for monitoring remote files and loading them into a glance image
# store.  This tool has been optimized for use on CoreOS but should work 
# for most files where an ETag is exposed.

# by default we retrieve the alpha image, set to  a different value to retrieve
# that release
release=${1:-"alpha"}

# use the following location as our local work space
tmplocation="/tmp/glancesync"

mkdir -p ${tmplocation}
pushd ${tmplocation} > /dev/null 2>&1

#retrieve the remote "ETag" header and set it to a variable
remote_etag=$(curl -I  http://storage.core-os.net/coreos/amd64-usr/beta/version.txt -k -s  | gawk '/ETag/ {print gensub("\"", "", "g", $2)}')

# source in the previously saved etag
source ${release}_version > /dev/null 2>&1

if [ "$remote_etag" == "$local_etag" ]; then
	echo "Everything is current"
	exit 0
else
	curl -s -L -O http://storage.core-os.net/coreos/amd64-usr/$release/version.txt
	. version.txt
	 
	#load openstack credentials
	. $HOME/.openstack || echo "No glance credentials available" && exit 1
	 
	# if we already have the image don't waste time
	glance image-show CoreOS-${release}-v${COREOS_VERSION} || skip="false"
	if [ "$skip" == "false" ]; then
    # change the following line to reflect the image to be chosen, openstack
    #  is used by default
		curl -s -L -O http://storage.core-os.net/coreos/amd64-usr/$release/coreos_production_openstack_image.img.bz2
		bunzip2 -d coreos_production_openstack_image.img.bz2
    # things can get confusing if you're constantly working with the same filename
    #  then again, this leaves you needing to clean up old images
		mv coreos_production_openstack_image.img coreos_${COREOS_VERSION}_openstack_image.img
		coreosimg=coreos_${COREOS_VERSION}_openstack_image.img
		 
		# perform actual image creation
    #  here we set the os_release, os_verison, os_family, and os_distro variables
    #  for intelligent consumption of images by scripts
		glance image-create --name CoreOS-${release}-v${COREOS_VERSION} --progress --is-public true \
			--property os_distro=coreos --property os_family=coreos --property os_version=${COREOS_VERSION} --property os_release=${release} \
			--disk-format qcow2 --container-format bare --min-disk 6 --file $coreosimg
		# grab UUID of newly created image
		new_glance_uuid=$(glance image-show CoreOS-${release}-v${COREOS_VERSION} | awk '/ id / {print $4}')
		# purge os_release tag from all previous versions of said release
		glance image-list --property "os_release=$release" \
			| gawk '$4 ~ /CoreOS/ && !/'"$new_glance_uuid"'/ {printf \
			"glance image-update --property os_distro=coreos --property \
			os_family=coreos --property os_version=%s --purge-props %s \n",\
			gensub(/CoreOS_v/, "", "g", $4), $2}' | sh
	fi
	echo "local_etag=$remote_etag" > ${release}_version
fi

popd > /dev/null 2>&1

# vim: set ts=2 sw=2 expandtab: