#!/usr/bin/env bash

# <Script Name>

# <Description what this module does>

# Written by <Author>

# GPL V3

########

# Source error handling, leave this in place

set -x

set -e

source /common.sh

install_cleanup_trap

systemctl disable resize2fs_once

# Generate some host keys for the image

ssh-keygen -A -v

systemctl disable regenerate_ssh_host_keys

# Rest of this script is inspired by https://github.com/adafruit/Raspberry-Pi-Installer-Scripts/blob/master/read-only-fs.sh

# 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() {

if grep $2 $1 >/dev/null; 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() {

if grep $2 $1 > /dev/null; 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() {

if grep $2 $1 > /dev/null; then

echo "exists"

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 space + string to last line --

# this is used for the single-line /boot/cmdline.txt file.

append2() {

if grep $2 $1>/dev/null; then

echo "exists"

else

# Not found; insert in file before EOF

sed -i "s/\'/ $3/g" $1 >/dev/null

fi

}

echo "Removing unwanted packages..."

apt-get remove -y --force-yes --purge triggerhappy logrotate dphys-swapfile fake-hwclock

apt-get -y --force-yes autoremove --purge

# Replace log management with busybox (use logread if needed)

echo "Installing ntp and busybox-syslogd..."

apt-get -y --force-yes install ntp ntpdate busybox-syslogd; dpkg --purge rsyslog

cp /lib/systemd/system/ntp.service /etc/systemd/system/ntp.service

replace /etc/systemd/system/ntp.service "PrivateTmp=true" "#PrivateTmp=true"

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"

# 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

if [ $READONLY_BOOT_IS_RW -n ]; then

replace /etc/fstab "vfat\s*defaults\s" "vfat defaults,ro "

fi

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"

append1 /etc/fstab "/var/lib/ntp" "tmpfs /var/lib/ntp tmpfs nodev,nosuid 0 0"

unpack /filesystem/boot /"${BASE_BOOT_MOUNT_PATH}"

# This would also work, but fails initially because it would also need to remove the init script doing the resize

#append2 /boot/cmdline.txt fastboot fastboot

#append2 /boot/cmdline.txt noswap noswap

#append2 /boot/cmdline.txt ro

# Add some helpful aliases to .bshrc for root

if [ $READONLY_BOOT_IS_RW -n ]; then

echo "alias ro='sudo mount -o remount,ro / ; sudo mount -o remount,ro /"${BASE_BOOT_MOUNT_PATH}"'" >> /root/.bashrc

echo "alias rw='sudo mount -o remount,rw / ; sudo mount -o remount,rw /"${BASE_BOOT_MOUNT_PATH}"'" >> /root/.bashrc

else

echo "alias ro='sudo mount -o remount,ro /'" >> /root/.bashrc

echo "alias rw='sudo mount -o remount,rw /'" >> /root/.bashrc

fi