diskimage-builder/diskimage_builder/elements/debian-minimal/root.d/75-debian-minimal-baseinstall

#!/bin/bash
# Copyright (c) 2014 Hewlett-Packard Development Company, L.P.
# Copyright (c) 2016 Andreas Florath (andreas@florath.net)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
#
# See the License for the specific language governing permissions and
# limitations under the License.

if [ ${DIB_DEBUG_TRACE:-0} -gt 0 ]; then
    set -x
fi
set -eu
set -o pipefail

# Writes the apt sources files.
# The description is passed in via line coded elements.
# (The approach using associative arrays for configuration faild,
#  because it looks that there is no way to handle defaults in
#  this case - and additionally we run with '-u'.)
function apt_sources_write {
    local APT_SOURCES_CONF="$1"

    sudo mkdir -p $TARGET_ROOT/etc/apt/sources.list.d

    echo "${APT_SOURCES_CONF}" \
        | while read line; do
            local name=$(echo ${line} | cut -d ":" -f 1)
            local value=$(echo ${line} | cut -d ":" -f 2-)
            echo "$value" | sudo tee $TARGET_ROOT/etc/apt/sources.list.d/${name}.list
        done
}

sudo mount -t proc none $TARGET_ROOT/proc
sudo mount -t sysfs none $TARGET_ROOT/sys
trap "sudo umount $TARGET_ROOT/proc; sudo umount $TARGET_ROOT/sys" EXIT

apt_get="sudo chroot $TARGET_ROOT /usr/bin/apt-get"

apt_sources_write "${DIB_APT_SOURCES_CONF}"

# Need to update to retrieve the signed Release file
$apt_get update

$apt_get clean
$apt_get dist-upgrade -y

$apt_get install -y busybox python sudo