Create standalone firmware update pkg for use with Imagr

create_fwupdate_pkg.sh

#!/bin/bash

set -o errexit


PKG_NAME="FWUpdate"
PKG_ID="se.gu.it.FWUpdateStandalone.pkg"
datestamp=$( date "+%Y%m%d" )
PKG_VERSION="1.0.$datestamp"


USAGE="Usage: $0 path/to/installer.app output_dir"
if [[ ! -f "$1/Contents/SharedSupport/InstallESD.dmg" ]]; then
    echo "$USAGE"
    exit 64
fi
if [[ ! -d "$2" ]]; then
    echo "$USAGE"
    exit 64
fi

installerapp="$1"
outputdir="$2"


tmpdir=$(mktemp -d -t fwupdate)
remove_tmpdir() {
    rm -rf "$tmpdir"
}
trap remove_tmpdir EXIT



echo "* Mounting InstallESD"
out=$( hdiutil attach -noverify -mountrandom /private/tmp "$installerapp/Contents/SharedSupport/InstallESD.dmg" )
esdmount=$( echo "$out" | grep /private/tmp | cut -f3 )
unmount_esd() {
    echo "* Unmounting InstallESD"
    hdiutil detach "$esdmount"
}
trap unmount_esd EXIT

echo "* Expanding firmware package"
expandedpkg="$tmpdir/expandedfw_pkg"
pkgutil --expand "$esdmount/Packages/FirmwareUpdate.pkg" "$expandedpkg"

echo "* Copying firmware update resources"
script_dir="tmpdir/scripts"
mkdir -p "$script_dir"
cp "$expandedpkg"/Scripts/postinstall_actions/update "$script_dir"/postinstall
printf '\n\nexit 0\n' >> "$script_dir"/postinstall
cp -R "$expandedpkg"/Scripts/Tools "$script_dir"/

echo "* Creating $PKG_NAME-$datestamp.pkg"
pkgbuild --nopayload --scripts "$script_dir" --identifier "$PKG_ID" --version "$PKG_VERSION" "$outputdir/$PKG_NAME-$datestamp.pkg"