nspawn-builder

#!/usr/bin/env bash
#
# nspawn-builder - nspawn-builder is a wrapper around mkosi that helps
# to generate images dynamically.
#
# Copyright (c) 2021 by Eduard Tolosa <edu4rdshl@protonmail.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http: #www.gnu.org/licenses/
#
#======================================================================
# Author: Eduard Tolosa
# Email: edu4rdshl@protonmail.com
# Github: www.github.com/edu4rdshl

VERSION="0.3"
STATIC_NAME="Nspawn Builder (https://nspawn.org)"

# Mkosi
MKOSI_CMD=$(command -v mkosi)
MKOSI_IMAGE_TYPES=()
MKOSI_ARGS=" --force"

# Enable/Disable specific format builds, leave empty to build in the specified format
DISABLE_TAR=""
DISABLE_RAW=""

# Create mkosi.cache/ directory if no exists, leave empty if you don't want it to be created
CREATE_MKOSI_CACHE_DIR="yes"
# Set the cache dir for mkosi to use. By default, it's /var/cache/mkosi.
MKOSI_CACHE_BASE_DIR="/var/cache/mkosi"

set -e

ctrl_c() {
  echo "Keyboard Interrupt detected, leaving."
  exit
}

trap ctrl_c 2


version() {
  echo "$STATIC_NAME $VERSION"
}

check_mkosi() {
  if [[ -z "$MKOSI_CMD" ]]; then
      echo "mkosi was not found in PATH, please install it https://github.com/systemd/mkosi"
      exit 1
  fi
}

check_and_create_dir() {
  local output_dir=""
  output_dir=$(grep "^Output=" "$1")
  output_dir=${output_dir#*=}
  output_dir=${output_dir%/*}/
  if [ ! -d "$output_dir" ]; then
    mkdir -p "$output_dir"
  fi
}

helpout() {
  echo "Menu usage for $STATIC_NAME $VERSION"
  echo
  echo "${0##*/} {COMMAND} [PARAMETER]"
  echo
  echo "Wrapper around mkosi for creating images in https://nspawn.org"
  echo "If you find an issue, report it to: https://github.com/nspawn/nspawn"
  echo
  echo "Commands:"
  echo -e "  -n/--name          \tBuild an image with the following parameters: <scripts-name>"
  echo -e " --notar             \tDo not build the TAR image."
  echo -e " --noraw             \tDo not build the RAW image."
  echo -e "  -h/--help          \tPrints this help message"
  echo -e "  -v/--version       \tPrints version info"
  echo
  echo "Parameters:"
  echo -e "  <scripts-name>     \tBase name of the scripts to use."
}

if [[ $# -eq 0 ]]; then
  helpout
  exit
fi

check_root() {
  if [[ $EUID -ne 0 ]]; then
    echo "This script requires root privileges to work, leaving."
    exit 1
  fi
}

build_image() {
  check_mkosi
  check_root

  scripts_name="$1"
  tar_default="${scripts_name}-tar.default"
  raw_default="${scripts_name}-raw.default"
  mkosi_extra="${scripts_name}.extra"
  mkosi_skeleton="${scripts_name}.skeleton"
  mkosi_build="${scripts_name}.build"
  mkosi_prepare="${scripts_name}.prepare"
  mkosi_postinst="${scripts_name}.postinst"
  mkosi_finalize="${scripts_name}.finalize"
  mkosi_mksquashfs_tool="${scripts_name}.mksquashfs-tool"
  mkosi_nspawn="${scripts_name}.nspawn"
  mkosi_cache="${scripts_name}.cache"
  mkosi_buildir="${scripts_name}.builddir"
  # mkosi_rootpw="${scripts_name}.rootpw"
  # mkosi_passphrase="${scripts_name}.passphrase"
  mkosi_secure_boot_crt="${scripts_name}.secure-boot.crt"
  mkosi_output="${scripts_name}.output"

  # Verify that Output= directory exists, and, if not then create it.
  # Also create images array
  if [ -f "$tar_default" ] && [[ -z $DISABLE_TAR ]]; then
    echo "Verifying that output directory for tar image exists..."
    check_and_create_dir "$tar_default"
    MKOSI_IMAGE_TYPES+=(" --default $tar_default")
  fi
  if [ -f "$raw_default" ] && [[ -z $DISABLE_RAW ]]; then
    echo "Verifying that output directory for raw image exists..."
    check_and_create_dir "$raw_default"
    MKOSI_IMAGE_TYPES+=(" --default $raw_default")
  fi

  if [ ${#MKOSI_IMAGE_TYPES[@]} -eq 0 ]; then
    echo "No $tar_default or $raw_default are available for the scripts name $scripts_name, leaving."
    exit 1
  fi

  # Create mkosi.cache/ dir if flag is set
  if [ ! -d "$mkosi_cache" ] && [[ -n $CREATE_MKOSI_CACHE_DIR ]]; then
    if [[ -n $MKOSI_CACHE_BASE_DIR ]]; then
      mkosi_cache="$MKOSI_CACHE_BASE_DIR/$mkosi_cache"
      fi
    mkdir -p "$mkosi_cache"
  fi

  # Workaround for Centos 7
  if [ "$scripts_name" == "centos7" ]; then
    MKOSI_ARGS+=" --without-unified-kernel-images"
  fi

  # Static options
  if [ -d "$mkosi_extra" ]; then
    MKOSI_ARGS+=" --extra-tree=$mkosi_extra"
  fi
  if [ -d "$mkosi_skeleton" ]; then
    MKOSI_ARGS+=" --skeleton-tree=$mkosi_skeleton"
  fi
  if [ -f "$mkosi_build" ]; then
    MKOSI_ARGS+=" --build-script=$mkosi_build"
  fi
  if [ -f "$mkosi_prepare" ]; then
    MKOSI_ARGS+=" --prepare-script=$mkosi_prepare"
  fi
  if [ -f "$mkosi_postinst" ]; then
    MKOSI_ARGS+=" --postinst-script=$mkosi_postinst"
  fi
  if [ -f "$mkosi_finalize" ]; then
    MKOSI_ARGS+=" --finalize-script=$mkosi_finalize"
  fi
  if [ -f "$mkosi_mksquashfs_tool" ]; then
    MKOSI_ARGS+=" --mksquashfs=$mkosi_mksquashfs_tool"
  fi
  if [ -f "$mkosi_nspawn" ]; then
    MKOSI_ARGS+=" --settings=$mkosi_nspawn"
  fi
  if [ -d "$mkosi_cache" ]; then
    MKOSI_ARGS+=" --cache=$mkosi_cache"
  fi
  if [ -d "$mkosi_buildir" ]; then
    MKOSI_ARGS+=" --build-dir=$mkosi_buildir"
  fi
  if [ -f "$mkosi_secure_boot_crt" ]; then
    MKOSI_ARGS+=" --secure-boot-certificate=$mkosi_secure_boot_crt"
  fi
  if [ -d "$mkosi_output" ]; then
    MKOSI_ARGS+=" --output-dir=$mkosi_output"
  fi

  # Build each image
  echo -e "\n\t Building mkosi images, it may take a while... \n"
  for image in "${MKOSI_IMAGE_TYPES[@]}"; do
    echo -e "\n Running $MKOSI_CMD $image $MKOSI_ARGS \n"
    $MKOSI_CMD $image $MKOSI_ARGS
  done
}


POSITIONAL=()
while [[ $# -gt 0 ]]; do
  key="$1"
  case $key in
  -v | --version)
    version
    exit
    ;;
  -h | --help)
    helpout
    exit
    ;;
  --notar )
    DISABLE_TAR="yes"
    shift
    ;;
  --noraw )
    DISABLE_RAW="yes"
    shift
    ;;
  -n | --name)
    build_image "$2"
    shift
    shift
    ;;
  *)
    POSITIONAL+=("$1")
    echo "Ivalid argument(s): $POSITIONAL"
    shift
    ;;
  esac
done
set -- "${POSITIONAL[@]}"