source /etc/sysconfig/condor-cloud

ERROR_MSG=

MISSING_DEPS= which qemu-img > /dev/null 2>&1 if [ $? -ne 0 ]; then

MISSING_DEPS="$MISSING_DEPS qemu-img"
return 1

fi

# # image_exists_global <image> # # Test to see if the given image is in the global image store. 0 is # returned if the image is present, 1 otherwise. # # This implementation uses the filesystem path $STORAGE as the global # store. # function image_exists_global {

IMAGE=$1
test -e $STORAGE/$IMAGE

}

# # image_exists_local <image> # # Test to see if the given image is in the local image store. 0 is # returned if the image is present, 1 otherwise. # # This implementation uses the filesystem path $CACHE as the local # store. # function image_exists_local {

IMAGE=$1
test -e $CACHE/$IMAGE

}

# # put_image <image> # # Put the image passed as the first argument, into the global image # store. Return 0 on success and 1 on any failure. # # This implementation uses the filesystem path $STORAGE as the global # store. # function put_image {

IMAGE=$1
IMAGE_NAME=$(basename $IMAGE)

LOCK="$STORAGE/$IMAGE_NAME.lock"

CAT=cat; which pv > /dev/null 2>&1 && CAT=pv

while ! ( set -o noclobber; echo "$$" > $LOCK ) 2> /dev/null; do
   echo "$LOCK held by $(cat $LOCK)" >2
   sleep $((RANDOM % 29))
done

trap 'rm -f $LOCK; exit $?' INT TERM EXIT

RC=0
if ! image_exists_global $IMAGE_NAME; then
   trap 'rm -f $LOCK; rm -f $STORAGE/$IMAGE_NAME; exit $?' INT TERM EXIT
   ERROR_MSG=$($CAT $IMAGE > $STORAGE/$IMAGE_NAME)
   if [ $? -eq 0 ]; then
      # Permissions on the image are entirely open
      chmod a=r $STORAGE/$IMAGE_NAME
   else
      RC=1
   fi
fi

rm -f $LOCK; trap - INT TERM EXIT

return $RC

}

# # get_image <image> # # Get an image from the global image store and make a copy locally for # use by guest VMs. Return 0 on success and 1 on any failure. # # This implementation uses the filesystem path $STORAGE as the global # store and $CACHE as the local. # function get_image {

IMAGE=$1

LOCK="$CACHE/$IMAGE.lock"

if ! image_exists_global $IMAGE; then
   ERROR_MSG="$STORAGE/$IMAGE not found"
   return 1
fi

while ! ( set -o noclobber; echo "$$" > $LOCK ) 2> /dev/null; do
   echo "$LOCK held by $(cat $LOCK)" >2
   sleep $((RANDOM % 29))
done

trap 'rm -f $LOCK; exit $?' INT TERM EXIT

if ! image_exists_local $IMAGE; then
   trap 'rm -f $LOCK; rm -f $CACHE/$IMAGE; exit $?' INT TERM EXIT
   ERROR_MSG=$(cp $STORAGE/$IMAGE $CACHE/$IMAGE)
   if [ $? -ne 0 ]; then
      return 1
   fi

   # libvirt chowns the qcow2 image to qemu.qemu so that qemu can
   # read/write it. The base image is not chowned, so we must make sure
   # it is readable by qemu. If this is not done, a common VMGahpLog
   # error will be:
   #   Failed to create libvirt domain: monitor socket did not show up.:
   #    No such file or directory
   # Other than readable, no one should ever write to the file, so write
   # perms are removed.
   chmod a+r $CACHE/$IMAGE
fi

rm -f $LOCK
trap - INT TERM EXIT

return 0

}

# # make_image <image> # # Create a qcow2 image based off the given image and place it in the # local image store. The qcow2 image is echo'd to stdout. The return # value has no meaning. # # This implementation uses the filesystem path $CACHE as the local # store. # function make_image {

BASE_IMAGE=$1
LOCATION=$2

LOCK="$CACHE/$BASE_IMAGE.lock"

if ! image_exists_local $BASE_IMAGE; then
   ERROR_MSG="$BASE_IMAGE not found"
   return 1
fi

#
# Use the $LOCK as a barrier in case the image is concurrently
# being added to the $CACHE. Granted, that is a case that should
# never happen. Unfortunately, the existence of the $LOCK cannot be
# used as an assertion condition because a concurrent get_image
# will briefly create $LOCK even when the $BASE_IMAGE is already in
# the $CACHE.
#
while ! ( set -o noclobber; echo "$$" > $LOCK ) 2> /dev/null; do
   echo "$LOCK held by $(cat $LOCK)" >2
   sleep $((RANDOM % 29))
done
trap 'rm -f $LOCK; exit $?' INT TERM EXIT

IMAGE=$LOCATION/$BASE_IMAGE.qcow2

qemu-img create -f qcow2 -b $CACHE/$BASE_IMAGE $IMAGE > /dev/null 2>&1
# XXX: test for success, give return value meaning

rm -f $LOCK

echo $IMAGE
return 0

}