mender-convert/modules/decompressinput.sh

#
# Copyright 2020 Northern.tech AS
#
#  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.

source modules/zip.sh
source modules/log.sh

# compression_type
#
# $1 - Path to the compressed disk image
#
# @return - The MENDER_COMPRESS_IMAGE compression type
#
function compression_type () {
  if [[ $# -ne 1 ]]; then
    log_fatal "compression_type() requires one argument"
  fi
  local -r disk_image="${1}"
  case "${disk_image}" in
    *.img | *.sdimg | *.wic | *.rpi-sdimg)
      echo "none"
      ;;
    *.gz)
      echo "gzip"
      ;;
    *.zip)
      echo "zip"
      ;;
    *.xz )
      echo "lzma"
      ;;
    * )
      log_fatal "Unsupported compression type: ${disk_image}. Please uncompress the image yourself."
      ;;
  esac
}

# Decompresses the given input image
#
#  $1 - Path to the compressed image
#  $2 - Path to the output directory
#
# @return - Name of the uncompressed image
#
function decompress_image () {
  if [[ $# -ne 2 ]]; then
    log_fatal "decompress_image() requires an image argument and an output directory"
  fi
  local -r input_image="${1}"
  local -r output_dir="${2}"
  local disk_image="${output_dir}/$(basename ${input_image})"
  case "$(compression_type ${disk_image})" in
    none )
      :
      ;;
    gzip )
      log_info "Decompressing ${disk_image}..."
      disk_image=${disk_image%.gz}
      zcat "${input_image}" > "${disk_image}"
      ;;
    zip )
      log_info "Decompressing ${disk_image}..."
      filename="$(zip_get_imgname ${input_image})"
      unzip "${input_image}" -d "${output_dir}" &>/dev/null
      disk_image="$(dirname ${disk_image})/${filename}"
      ;;
    lzma )
      log_info "Decompressing ${disk_image}..."
      disk_image=${disk_image%.xz}
      xzcat "${input_image}" > "${disk_image}"
      ;;
    * )
      log_fatal "Unsupported input image format: ${input_image}. We support: '.img', '.gz', '.zip', '.xz'."
      ;;
  esac
  echo "${disk_image}"
}