Create macOS flat Package from .app in /Applications

createPackage.sh

#!/bin/sh

TempDir="/tmp/pkg"
AppPath=$1
TargetPath=$2
PackageIdentifier=$3
Certificate=$4

if [ $# -ne 3 ]
then
	echo "Usage: $0 <AppPath> <TargetPath> <PackageIdentifier> <CertificateCommonName or CertificateChecksum>"
	exit 1
fi

rm -rf ${TempDir}
mkdir -p ${TempDir}
mkdir -p ${TargetPath}
cp -r ${AppPath} ${TempDir}

cd /tmp

pkgbuild --analyze --root ${TempDir} package.plist
pkgbuild --root ${TempDir} --component-plist package.plist --identifier ${PackageIdentifier} package.pkg
productbuild --synthesize --package package.pkg packageDistribution.xml
productbuild --distribution ./packageDistribution.xml --package-path . InstallerPackage.pkg
productsign  --timestamp=none --sign "$Certificate" InstallerPackage.pkg SignedInstallerPackage.pkg

rm package.plist
rm package.pkg
rm packageDistribution.xml
rm -rf ${TempDir}
mv SignedInstallerPackage.pkg ${TargetPath}