pi_readonly_auto.sh

pi_readonly_auto_sh

#!/bin/bash

# based on
# https://learn.adafruit.com/read-only-raspberry-pi/

if [ $(id -u) -ne 0 ]; then
	echo "Installer must be run as root."
	echo "Try 'sudo bash $0'"
	exit 1
fi

echo "____________   THIS IS A ONE-WAY"
echo "OPERATION. THERE IS NO SCRIPT TO"
echo "REVERSE THIS SETUP! ALL other system"
echo "config should be complete before using"
echo "this script. MAKE A BACKUP FIRST."
echo
echo "Run time ~5 minutes. Reboot required."
echo
echo -n "CONTINUE? [y/N] "
read
if [[ ! "$REPLY" =~ ^(yes|y|Y)$ ]]; then
	echo "Canceled."
	exit 0
fi

# FEATURE PROMPTS ----------------------------------------------------------
# Installation doesn't begin until after all user input is taken.

INSTALL_RW_JUMPER=0
INSTALL_HALT=0
INSTALL_WATCHDOG=0

# Given a list of strings representing options, display each option
# preceded by a number (1 to N), display a prompt, check input until
# a valid number within the selection range is entered.
selectN() {
	for ((i=1; i<=$#; i++)); do
		echo $i. ${!i}
	done
	echo
	REPLY=""
	while :
	do
		echo -n "SELECT 1-$#: "
		read
		if [[ $REPLY -ge 1 ]] && [[ $REPLY -le $# ]]; then
			return $REPLY
		fi
	done
}

SYS_TYPES=(Pi\ 3\ /\ Pi\ Zero\ W All\ other\ models)
WATCHDOG_MODULES=(bcm2835_wdog bcm2708_wdog)
OPTION_NAMES=(NO YES)

echo  "Enable boot-time read/write jumper? on 21 "
INSTALL_RW_JUMPER=1
RW_PIN=21


echo "Install GPIO-halt utility on gpio 33 "
INSTALL_HALT=1
HALT_PIN=33


echo "Enable kernel panic watchdog"
INSTALL_WATCHDOG=1
WD_TARGET=1

# VERIFY SELECTIONS BEFORE CONTINUING --------------------------------------

echo
if [ $INSTALL_RW_JUMPER -eq 1 ]; then
	echo "Boot-time R/W jumper: YES (GPIO$RW_PIN)"
else
	echo "Boot-time R/W jumper: NO"
fi
if [ $INSTALL_HALT -eq 1 ]; then
	echo "Install GPIO-halt: YES (GPIO$HALT_PIN)"
else
	echo "Install GPIO-halt: NO"
fi
if [ $INSTALL_WATCHDOG -eq 1 ]; then
	echo "Enable watchdog: YES (${SYS_TYPES[WD_TARGET-1]})"
else
	echo "Enable watchdog: NO"
fi
echo
echo -n "CONTINUE? [y/N] "
read
if [[ ! "$REPLY" =~ ^(yes|y|Y)$ ]]; then
	echo "Canceled."
	exit 0
fi

# START INSTALL ------------------------------------------------------------
# All selections have been validated at this point...

# Given a filename, a regex pattern to match and a replacement string:
# Replace string if found, else no change.
# (# $1 = filename, $2 = pattern to match, $3 = replacement)
replace() {
	grep $2 $1 >/dev/null
	if [ $? -eq 0 ]; then
		# Pattern found; replace in file
		sed -i "s/$2/$3/g" $1 >/dev/null
	fi
}

# Given a filename, a regex pattern to match and a replacement string:
# If found, perform replacement, else append file w/replacement on new line.
replaceAppend() {
	grep $2 $1 >/dev/null
	if [ $? -eq 0 ]; then
		# Pattern found; replace in file
		sed -i "s/$2/$3/g" $1 >/dev/null
	else
		# Not found; append on new line (silently)
		echo $3 | sudo tee -a $1 >/dev/null
	fi
}

# Given a filename, a regex pattern to match and a string:
# If found, no change, else append file with string on new line.
append1() {
	grep $2 $1 >/dev/null
	if [ $? -ne 0 ]; then
		# Not found; append on new line (silently)
		echo $3 | sudo tee -a $1 >/dev/null
	fi
}

# Given a filename, a regex pattern to match and a string:
# If found, no change, else append space + string to last line --
# this is used for the single-line /boot/cmdline.txt file.
append2() {
	grep $2 $1 >/dev/null
	if [ $? -ne 0 ]; then
		# Not found; insert in file before EOF
		sed -i "s/\'/ $3/g" $1 >/dev/null
	fi
}

echo
echo "Starting installation..."
echo "Updating package index files..."
apt-get update

echo "Removing unwanted packages..."
#apt-get remove -y --force-yes --purge triggerhappy cron logrotate dbus \
# dphys-swapfile xserver-common lightdm fake-hwclock
# Let's keep dbus...that includes avahi-daemon, a la 'raspberrypi.local',
# also keeping xserver & lightdm for GUI login (WIP, not working yet)
apt-get remove -y --force-yes --purge triggerhappy avahi-daemon \
 dphys-swapfile fake-hwclock
apt-get -y --force-yes autoremove --purge

# Replace log management with (use logread if needed)
#echo "Installing busybox-syslogd..."
#apt-get -y --force-yes install busybox-syslogd; dpkg --purge rsyslog

echo "Configuring system..."

# Install boot-time R/W jumper test if requested
GPIOTEST="gpio -g mode $RW_PIN up\n\
if [ \`gpio -g read $RW_PIN\` -eq 0 ] ; then\n\
\tmount -o remount,rw \/\n\
\tmount -o remount,rw \/boot\n\
fi\n"
if [ $INSTALL_RW_JUMPER -ne 0 ]; then
	apt-get install -y --force-yes wiringpi
	# Check if already present in rc.local:
	grep "gpio -g read" /etc/rc.local >/dev/null
	if [ $? -eq 0 ]; then
		# Already there, but make sure pin is correct:
		sed -i "s/^.*gpio\ -g\ read.*$/$GPIOTEST/g" /etc/rc.local >/dev/null

	else
		# Not there, insert before final 'exit 0'
		sed -i "s/^exit 0/$GPIOTEST\\nexit 0/g" /etc/rc.local >/dev/null
	fi
fi

# Install watchdog if requested
if [ $INSTALL_WATCHDOG -ne 0 ]; then
	apt-get install -y --force-yes watchdog
	# $MODULE is specific watchdog module name
	MODULE=${WATCHDOG_MODULES[($WD_TARGET-1)]}
	# Add to /etc/modules, update watchdog config file
	append1 /etc/modules $MODULE $MODULE
	replace /etc/watchdog.conf "#watchdog-device" "watchdog-device"
	replace /etc/watchdog.conf "#max-load-1" "max-load-1"
	# Start watchdog at system start and start right away
	# Raspbian Stretch needs this package installed first
	apt-get install -y --force-yes insserv
	insserv watchdog; /etc/init.d/watchdog start
	# Additional settings needed on Jessie
	append1 /lib/systemd/system/watchdog.service "WantedBy" "WantedBy=multi-user.target"
	systemctl enable watchdog
	# Set up automatic reboot in sysctl.conf
	replaceAppend /etc/sysctl.conf "^.*kernel.panic.*$" "kernel.panic = 10"
fi

# Install gpio-halt if requested
if [ $INSTALL_HALT -ne 0 ]; then
	apt-get install -y --force-yes wiringpi
	echo "Installing gpio-halt in /usr/local/bin..."
	cd /tmp
	curl -LO https://github.com/adafruit/Adafruit-GPIO-Halt/archive/master.zip
	unzip master.zip
	cd Adafruit-GPIO-Halt-master
	make
	mv gpio-halt /usr/local/bin
	cd ..
	rm -rf Adafruit-GPIO-Halt-master

	# Add gpio-halt to /rc.local:
	grep gpio-halt /etc/rc.local >/dev/null
	if [ $? -eq 0 ]; then
		# gpio-halt already in rc.local, but make sure correct:
		sed -i "s/^.*gpio-halt.*$/\/usr\/local\/bin\/gpio-halt $HALT_PIN \&/g" /etc/rc.local >/dev/null
	else
		# Insert gpio-halt into rc.local before final 'exit 0'
		sed -i "s/^exit 0/\/usr\/local\/bin\/gpio-halt $HALT_PIN \&\\nexit 0/g" /etc/rc.local >/dev/null
	fi
fi

# Add fastboot, noswap and/or ro to end of /boot/cmdline.txt
append2 /boot/cmdline.txt fastboot fastboot
append2 /boot/cmdline.txt noswap noswap
append2 /boot/cmdline.txt ro^o^t ro

# Move /var/spool to /tmp
rm -rf /var/spool
ln -s /tmp /var/spool

# Move /var/lib/lightdm and /var/cache/lightdm to /tmp
rm -rf /var/lib/lightdm
rm -rf /var/cache/lightdm
ln -s /tmp /var/lib/lightdm
ln -s /tmp /var/cache/lightdm

# Make SSH work
replaceAppend /etc/ssh/sshd_config "^.*UsePrivilegeSeparation.*$" "UsePrivilegeSeparation no"
# bbro method (not working in Jessie?):
#rmdir /var/run/sshd
#ln -s /tmp /var/run/sshd

# Change spool permissions in var.conf (rondie/Margaret fix)
replace /usr/lib/tmpfiles.d/var.conf "spool\s*0755" "spool 1777"

# Move dhcpd.resolv.conf to tmpfs
touch /tmp/dhcpcd.resolv.conf
rm /etc/resolv.conf
ln -s /tmp/dhcpcd.resolv.conf /etc/resolv.conf

# Make edits to fstab
# make / ro
# tmpfs /var/log tmpfs nodev,nosuid 0 0
# tmpfs /var/tmp tmpfs nodev,nosuid 0 0
# tmpfs /tmp     tmpfs nodev,nosuid 0 0
replace /etc/fstab "vfat\s*defaults\s" "vfat    defaults,ro "
replace /etc/fstab "ext4\s*defaults,noatime\s" "ext4    defaults,noatime,ro "
append1 /etc/fstab "/var/log" "tmpfs /var/log tmpfs nodev,nosuid 0 0"
append1 /etc/fstab "/var/tmp" "tmpfs /var/tmp tmpfs nodev,nosuid 0 0"
append1 /etc/fstab "\s/tmp"   "tmpfs /tmp    tmpfs nodev,nosuid 0 0"

# PROMPT FOR REBOOT --------------------------------------------------------

echo "Done."
echo
echo "Settings take effect on next boot."
echo
echo -n "REBOOT NOW? [y/N] "
read
if [[ ! "$REPLY" =~ ^(yes|y|Y)$ ]]; then
	echo "Exiting without reboot."
	exit 0
fi
echo "Reboot started..."
reboot
exit 0