--- /dev/null
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Install an already built grml-debootstrap.deb.
+# Wrapper around apt-get install for usage inside docker.
+
+set -eu -o pipefail
+
+if [ "$#" -ne 1 ]; then
+ echo "$0: Invalid arguments" >&2
+ echo "Expect: $0 DEB_NAME" >&2
+ exit 1
+fi
+DEB_NAME="$1"
+
+apt-get update
+# docker images can be relatively old, especially for unstable.
+apt-get -y upgrade
+apt-get -y install "$DEB_NAME"