function show_options () {
    echo "Usage: ${SCRIPTNAME} [OPTION]... [ELEMENT]..."
    echo
    echo "Options:"
    echo "    -a i386|amd64|armhf -- set the architecture of the image(default amd64)"
    echo "    -o imagename -- set the imagename of the output image file(default image)"
    echo "    -t qcow2,tar,vhd,docker,aci,raw -- set the image types of the output image files (default qcow2)"
    echo "       File types should be comma separated. VHD outputting requires the vhd-util"
    echo "       executable be in your PATH. ACI outputting requires the ACI_MANIFEST "
    echo "       environment variable be a path to a manifest file."
    echo "    -x -- turn on tracing (use -x -x for very detailed tracing)"
    echo "    -u -- uncompressed; do not compress the image - larger but faster"
    echo "    -c -- clear environment before starting work"
    echo "    --image-size size -- image size in GB for the created image"
    echo "    --image-cache directory -- location for cached images(default ~/.cache/image-create)"
    echo "    --max-online-resize size -- max number of filesystem blocks to support when resizing."
    echo "       Useful if you want a really large root partition when the image is deployed."
    echo "       Using a very large value may run into a known bug in resize2fs."
    echo "       Setting the value to 274877906944 will get you a 1PB root file system."
    echo "       Making this value unnecessarily large will consume extra disk space "
    echo "       on the root partition with extra file system inodes."
    echo "    --min-tmpfs size -- minimum size in GB needed in tmpfs to build the image"
    echo "    --mkfs-options -- option flags to be passed directly to mkfs."
    echo "       Options should be passed as a single string value."
    echo "    --no-tmpfs -- do not use tmpfs to speed image build"
    echo "    --offline -- do not update cached resources"
    echo "    --qemu-img-options -- option flags to be passed directly to qemu-img."
    echo "       Options need to be comma separated, and follow the key=value pattern."
    echo "    --root-label label -- label for the root filesystem.  Defaults to 'cloudimg-rootfs'."
    echo "    --ramdisk-element -- specify the main element to be used for building ramdisks."
    echo "       Defaults to 'ramdisk'.  Should be set to 'dracut-ramdisk' for platforms such"
    echo "       as RHEL and CentOS that do not package busybox."
    echo "    --install-type -- specify the default installation type. Defaults to 'source'. Set to 'package' to use package based installations by default."
    echo "    --docker-target -- specify the repo and tag to use if the output type is docker. Defaults to the value of output imagename"
    if [ "$IS_RAMDISK" == "0" ]; then
        echo "    -n skip the default inclusion of the 'base' element"
        echo "    -p package[,package,package] -- list of packages to install in the image"
        fi
   echo "    -h|--help -- display this help and exit"
   echo "    --version -- display version and exit"
   echo
   echo "ELEMENTS_PATH will allow you to specify multiple locations for the elements."
   echo
   echo "NOTE: At least one distribution root element must be specified."
   echo
   echo "NOTE: If using the VHD output format you need to have a patched version of vhd-util installed for the image"
   echo "      to be bootable. The patch is available here: https://github.com/emonty/vhd-util/blob/master/debian/patches/citrix"
   echo "      and a PPA with the patched tool is available here: https://launchpad.net/~openstack-ci-core/+archive/ubuntu/vhd-util"
   echo
   echo "Examples:"
   if [ "$IS_RAMDISK" == "0" ]; then
       echo "    ${SCRIPTNAME} -a amd64 -o ubuntu-amd64 vm ubuntu"
       echo "    export ELEMENTS_PATH=~/source/tripleo-image-elements/elements"
       echo "    ${SCRIPTNAME} -a amd64 -o fedora-amd64-heat-cfntools vm fedora heat-cfntools"
   else
       echo "    ${SCRIPTNAME} -a amd64 -o fedora-deploy deploy fedora"
       echo "    ${SCRIPTNAME} -a amd64 -o ubuntu-ramdisk ramdisk ubuntu"
   fi
}