flash-image.sh

#!/bin/bash
# Copyright (C) 2022 Toni Blåfield
# 
# edge-image-tools is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# edge-image-tools 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 Lesser General Public License for more details.
# 
# You should have received a copy of the GNU Lesser General Public License
# along with edge-image-tools. If not, see <http://www.gnu.org/licenses/>.

set -e

listDevices() {
	devices=$(find /dev/ -type b -name "sd[a-z]")
	echo -e "USAGE: ${0} <flash=1> [block-device] \nList of SCSI block devices:\n${devices}"
}

# For windows machines, this check is not valid so omit it
kernel=$(uname -a)
kernel=${kernel,,}
userId=$(id -u)

[[ ${kernel} =~ "mingw" || ${kernel} =~ "cygwin" ]] || { (( userId != 0 )) && echo "Bash Emulator not detected and current user not root/sudo. This script must be run as root user or with sudo privileges." && exit 1; }

doFlash=${1} && [[ ${doFlash} != 0 && ${doFlash} != 1 ]] && echo "Invalid argument for: <flash>" && listDevices && exit 1

[ "${doFlash}" -eq 1 ] && targetDev="${2}" && [ -z "${targetDev}" ] && echo "Given targetDev is empty or not set." && listDevices && exit 1
[ "${doFlash}" -eq 1 ] && [[ ! -b ${targetDev} ]] && echo "Block device '${targetDev}' does not exist!" && listDevices && exit 1

paramsFile='local/local_config'

# Read and parse common variables
# shellcheck disable=SC1090
source "${paramsFile}"

workingDir="${HOME}/Downloads"

imgServer=${IMAGE_SERVER_URL} && [ -z "${imgServer}" ] && echo "Variable imgServer is empty or not set." && exit 1
sasToken=${SAS_TOKEN_URL_QUERY} && [ -z "${sasToken}" ] && echo "Variable sasToken is empty or not set." && exit 1

imgVerFile=${IMAGE_VER_FILE} && [ -z "${imgVerFile}" ] && echo "Variable imgVerFile is empty or not set." && exit 1
imgOs=${IMAGE_OS} && [ -z "${imgOs}" ] && echo "Variable imgOs is empty or not set." && exit 1
imgArch=${IMAGE_ARCH} && [ -z "${imgArch}" ] && echo "Variable imgArch is empty or not set." && exit 1

# Complete URL for fetching the latest image version
imgVerFileUrl="${imgServer}/${imgOs}/${imgArch}/${imgVerFile}${sasToken}"

imgFilesListUrl="${imgServer}/${imgOs}/${imgArch}${sasToken}&comp=list&restype=directory"


################################################################################
################################	START	####################################
################################################################################

pushd "${workingDir}"

[ "${doFlash}" -eq 1 ] && read -rp "DATA LOSS WARNING! Selected device: ${targetDev}. Continue? (y/n) " ans

[ "${doFlash}" -eq 1 ] && [[ ${ans} != "y" ]] && echo "Answer was not YES. Exiting." && exit 1

imgVer=$(curl -f -L "${imgVerFileUrl}")
availableImages=$(curl -f -L "${imgFilesListUrl}")
imgFileZip=$(echo "$availableImages" | tr '<>' '\n' | grep -E -e ".*-.*_.*_${imgVer}\..*")

[ -z "${imgFileZip}" ] && echo "ERROR: Could not find the correct image file with following parameters: os: ${imgOs} arch: ${imgArch} ver: ${imgVer}. Abort." && exit 1

fileNoExt=${imgFileZip%.*}

imgFile="${fileNoExt}"
imgFileUrl="${imgServer}/${imgOs}/${imgArch}/${imgFileZip}${sasToken}"

if [ ! -f "${imgFile}" ]; then
	{ [ -f "${imgFileZip}" ] && echo "NOTE: File already exists. No need to download."; } || curl -f -L -o "${imgFileZip}" "${imgFileUrl}"
	winpty unxz -vv -d -k "${imgFileZip}"
else
	echo "NOTE: Image file already exists. No need to download/unpack."
fi

if [ "${doFlash}" -eq 1 ]; then
	echo "Writing image.."

	count=0
	countMax=30
	while (( count < countMax )) && ! dd status=progress if="${imgFile}" of="${targetDev}" bs=64k; do
		echo ""
		(( count += 1 ))
		sleep 1
	done
	(( count >= countMax )) && echo "ERROR: Failed to write image to device." && exit 1

	echo "Image written to target device."
fi

popd

echo "${0} DONE"