include image reference as source in every tar file header

Signed-off-by: Avi Deitcher <avi@deitcher.net>

test/cases/000_build/001_tarheaders/test.sh

@@ -0,0 +1,38 @@
+#!/bin/sh
+# SUMMARY: Check that tar output format build contains proper headers for each file
+# LABELS:
+
+set -e
+
+# Source libraries. Uncomment if needed/defined
+#. "${RT_LIB}"
+. "${RT_PROJECT_ROOT}/_lib/lib.sh"
+
+NAME=tarheaders
+
+clean_up() {
+	rm -f ${NAME}*
+}
+
+trap clean_up EXIT
+
+# do not include the sbom, because the SBoM unique IDs per file/package are *not* deterministic,
+# (currently based upon syft), and thus will make the file non-reproducible
+linuxkit build --no-sbom --format tar --name "${NAME}" ./test.yml
+
+# Check that the tarball contains the expected headers
+# see that python is installed
+PYTHON=
+if which python ; then PYTHON=python ; elif which python3; then PYTHON=python3 ; else
+echo "Failed to find any executable python or python3"
+exit 1
+fi
+FAILED=$(python ./tarheaders.py "${NAME}.tar")
+
+if [ -n "${FAILED}" ]; then
+	echo "Failed to find linuxkit.packagesource headers for the following files:"
+	echo "${FAILED}"
+	exit 1
+fi
+
+exit 0