install-netkit-jh.sh

#!/usr/bin/env bash

# Download and install netkit-jh in home directory
# Modified from Peter Norris' original install script

#
# Users experiencing issues during the installation process
# should be able to report back with the exact command that
# has failed.
#
set -e

# Default variables
VERSION="VERSION_NUMBER"
TARGET_INSTALL_DIR="${HOME}/netkit-jh"
BACKUP_INSTALL_DIR="${HOME}/netkit-jh-$(date '+%F_%H-%M-%S')"
INSTALL_APT_PACKAGES=true
DOWNLOAD_FILES=true
DOWNLOAD_DIR="/tmp"
DOWNLOAD_URL_PREFIX="https://github.com/netkit-jh/netkit-jh-build/releases/download/$VERSION/"

# Environment variables required for Netkit-JH to run
NK_ENV_VARS="
#=== NETKIT VARIABLES ===
# additions for netkit
export NETKIT_HOME=\"${TARGET_INSTALL_DIR}\"
export MANPATH=\"\$MANPATH:\$NETKIT_HOME/man\"
export PATH=\"\$PATH:\$NETKIT_HOME/bin\"
#=== NETKIT VARIABLES END ==="

# If desired, you can specify a directory where the files have already been 
# extracted (primarily for development purposes)
KERNEL_EXTRACTED_FILES=""
FS_EXTRACTED_FILES=""
CORE_EXTRACTED_FILES="" 

# Process arguments
for i in "$@"
do
case $i in
    --target-dir=*)
    TARGET_INSTALL_DIR="${i#*=}"
    shift # past argument=value
    ;;
    --backup-dir=*)
    BACKUP_INSTALL_DIR="${i#*=}"
    shift # past argument=value
    ;;
    --no-packages)
    INSTALL_APT_PACKAGES=false
    shift # past argument=value
    ;;
    --no-packages)
    DOWNLOAD_FILES=false
    shift # past argument=value
    ;;
    --download-url=*)
    DOWNLOAD_URL_PREFIX="${i#*=}"
    shift # past argument=value
    ;;
    --download-dir=*)
    DOWNLOAD_DIR="${i#*=}"
    shift # past argument=value
    ;;
    --kernel-files=*)
    KERNEL_EXTRACTED_FILES="${i#*=}"
    shift # past argument=value
    ;;
    --fs-files=*)
    FS_EXTRACTED_FILES="${i#*=}"
    shift # past argument=value
    ;;
    --core-files=*)
    CORE_EXTRACTED_FILES="${i#*=}"
    shift # past argument=value
    ;;
    -h|--help)
    echo "Netkit-JH Installation script
usage: install-netkit-jh-${VERSION}.sh [arguments]

Available arguments:
--target-dir            : Absolute path to a folder to install Netkit to.
--backup-dir            : Absolute path to where the previous installation of Netkit should be moved to.
--no-packages           : Do not download packages required to run Netkit from apt.
--no-download           : Do not download kernel/fs/core files if they are not found inside download-dir.
--download-url          : Specify the URL prefix to download the files from.
--download-dir          : Path to where the files are downloaded to.
--kernel-files          : Absolute path to where the kernel files have been extracted. This path should
                          point to the netkit-jh folder within the extracted archive.
--fs-files              : Absolute path to where the filesystem files have been extracted. This path should
                          point to the netkit-jh folder within the extracted archive.
--core-files            : Absolute path to where the core files have been extracted. This path should point
                          to the netkit-jh folder within the extracted archive.

"
    exit 0
    ;;
    *)
          # unknown option
    ;;
esac
done

# Runtime variables
PREVIOUS_INSTALL_FOUND=false # Was a previous installation found and backed up?

# Takes in a directory and array of file names and returns 0 if all were found, else 1 if any of them weren't failed
check_files_exist() 
{
	DIRECTORY="$1"
	shift;
	FILES=("$@")
	
	FAILED=0
	
	for FILE in "${FILES[@]}"; do
		if [ ! -f "${DIRECTORY}/${FILE}" ]; then
			echo "Cannot find file ${DIRECTORY}/${FILE}."
			FAILED=1
		fi
	done
	
	return ${FAILED}
}

# Rename target dir if already exists
if [ -d "${TARGET_INSTALL_DIR}" ] ; then
	echo "${TARGET_INSTALL_DIR} already exists. Renaming it to ${BACKUP_INSTALL_DIR} so contents are not disturbed."
	mv "${TARGET_INSTALL_DIR}" "${BACKUP_INSTALL_DIR}"
	PREVIOUS_INSTALL_FOUND=true
fi

mkdir -p "${TARGET_INSTALL_DIR}"

# Check whether they've specified extracted files
if [ -n "${KERNEL_EXTRACTED_FILES}" -a -n "${FS_EXTRACTED_FILES}" -a -n "${CORE_EXTRACTED_FILES}" ]; then
	cp -r "${KERNEL_EXTRACTED_FILES}/." "${TARGET_INSTALL_DIR}"
	cp -r "${FS_EXTRACTED_FILES}/." "${TARGET_INSTALL_DIR}"
	cp -r "${CORE_EXTRACTED_FILES}/." "${TARGET_INSTALL_DIR}"
else
	files_expected=("release-${VERSION}.sha256" "netkit-core-${VERSION}.tar.bz2" "netkit-fs-${VERSION}.tar.bz2" "netkit-kernel-${VERSION}.tar.bz2")
	check_files_exist "${DOWNLOAD_DIR}" "${files_expected[@]}"
	files_exist=$?
	
	if [ ${files_exist} -eq 0 ]; then
		# If all expected files are found, we can continue
		echo "Downloaded files found in ${DOWNLOAD_DIR}, continuing..."
	else
		# Otherwise, we can download the files
		if [ "${DOWNLOAD_FILES}" = "true" ]; then
			mkdir -p "${DOWNLOAD_DIR}"

			wget -O "${DOWNLOAD_DIR}/release-${VERSION}.sha256" --show-progress "${DOWNLOAD_URL_PREFIX}/release-${VERSION}.sha256"
			wget -O "${DOWNLOAD_DIR}/netkit-core-${VERSION}.tar.bz2" --show-progress "${DOWNLOAD_URL_PREFIX}/netkit-core-${VERSION}.tar.bz2"
			wget -O "${DOWNLOAD_DIR}/netkit-fs-${VERSION}.tar.bz2" --show-progress "${DOWNLOAD_URL_PREFIX}/netkit-fs-${VERSION}.tar.bz2"
			wget -O "${DOWNLOAD_DIR}/netkit-kernel-${VERSION}.tar.bz2" --show-progress "${DOWNLOAD_URL_PREFIX}/netkit-kernel-${VERSION}.tar.bz2"
		else
			echo "The files above were not found and downloading is disabled, exiting installation."
			exit 1
		fi
	fi
	
	(cd ${DOWNLOAD_DIR}; sha256sum -c release-${VERSION}.sha256)
	FILES_INVALID=$?
	
	if [ ${FILES_INVALID} -eq 1 ]; then
		echo "File checksums failed to verify, please delete the downloaded files and re-run this script." >&2
		exit 1
	fi
	
	# strip-components removes the netkit-jh directory
	tar -xjvC "${TARGET_INSTALL_DIR}" --strip-components=1 -f ${DOWNLOAD_DIR}/netkit-core-${VERSION}.tar.bz2
	tar -xjvC "${TARGET_INSTALL_DIR}" --strip-components=1 -f ${DOWNLOAD_DIR}/netkit-fs-${VERSION}.tar.bz2
	tar -xjvC "${TARGET_INSTALL_DIR}" --strip-components=1 -f ${DOWNLOAD_DIR}/netkit-kernel-${VERSION}.tar.bz2
fi

RC_FILES=("${HOME}/.bashrc" "${HOME}/.zshrc")
for RC_FILE in "${RC_FILES[@]}"; do
	# Check whether this file exists
	if [ ! -f ${RC_FILE} ]; then
		continue
	fi
	
	# Backup existing file with date and time as part of filename
	BAK_FILE="${RC_FILE}_$(date "+%F_%H-%M-%S").bak"
	cp "${RC_FILE}" "${BAK_FILE}"

	# Check whether the netkit variables header exists, if not, wipe all cases of netkit
	if [ -z "$(grep "=== NETKIT VARIABLES ===" "${RC_FILE}")" ]; then
		# strip out any lines containing the word "netkit" (case insensitive) from bashrc
		grep -iv "netkit" "${BAK_FILE}" > "${RC_FILE}"
	else
		# Otherwise, just wipe between the headers
		sed -i "/^#=== NETKIT VARIABLES ===/,/^#=== NETKIT VARIABLES END ===/d;" ${RC_FILE}
	fi

	# Append Netkit additions to bashrc  
	echo "$NK_ENV_VARS" >> "${RC_FILE}"

	# Set the environment variables so ./check_configuration.sh can be ran
	source "${RC_FILE}"

done

# make (for lab.dep) and net-tools (for tap) needed on ubuntu 18.04
if [ "${INSTALL_APT_PACKAGES}" = true ]; then
	echo "Installing packages to run netkit..."
	sudo apt-get update && sudo apt-get install xterm make net-tools curl
fi

# Restore config + handle updating config
if [ "${PREVIOUS_INSTALL_FOUND}" = true ]; then
	echo ""
	echo "Restoring configuration from previous installation."
	${TARGET_INSTALL_DIR}/setup_scripts/handle_config.sh "${BACKUP_INSTALL_DIR}" "${TARGET_INSTALL_DIR}"
fi

echo "Netkit-JH should now be installed. Checking configuration..."

# Ubuntu (and similar) distributions prevent .bashrc from running in a
# non-interactive shell. So here we can just evaluate the environment variables
# export commands
eval "$NK_ENV_VARS"

cd "${TARGET_INSTALL_DIR}/setup_scripts"
./check_configuration.sh || exit 1

# Encourage user to set environment variables for the current terminal
echo ""
echo "To use Netkit-JH now, open a new terminal window or run source ~/.bashrc (or .zshrc if using Zsh)"

echo ""
echo -e "\033[1mRun ${TARGET_INSTALL_DIR}/setup_scripts/change_terminal.sh to change your terminal emulator (highly recommended!)\033[0m"