#!/bin/sh
# Build Debian root filesystem

IMAGE2="$1" # For example "/artifacts/debian-buster-armhf"
ARCH="$2" # For example "armhf"
DIST="$3" # For example "buster"

set -e

case "${ARCH}" in
armhf)
	KERNEL=linux-image-armmp
	;;
arm64)
	KERNEL=linux-image-arm64
	;;
*)
	echo "Can't decide kernel package for \"${ARCH}\""
	exit 1
	;;
esac

# Create fresh empty directory
TMP=$(mktemp -d tmp.XXXXXX)
cd "${TMP}"

# Build a Debian root filesystem (first stage)
debootstrap \
  --arch="${ARCH}" \
  --verbose \
  --variant=minbase \
  --foreign \
  --include=\
netbase,\
ifupdown,\
net-tools,\
isc-dhcp-client,\
${KERNEL},\
systemd-sysv,\
u-boot-tools,\
openssh-server \
  "${DIST}" \
  debian \
  "http://deb.debian.org/debian/"

# Randomly generated root password
PASSWORD=$(pwgen -B -A 6 1)

# Write apt sources config
case "${DIST}" in
sid)
	tee debian/tmp/sources.list <<- EOF
deb http://deb.debian.org/debian ${DIST} main
deb-src http://deb.debian.org/debian ${DIST} main
EOF
	;;
*)
	tee debian/tmp/sources.list <<- EOF
deb http://deb.debian.org/debian ${DIST} main
deb-src http://deb.debian.org/debian ${DIST} main
deb http://deb.debian.org/debian ${DIST}-updates main
deb-src http://deb.debian.org/debian ${DIST}-updates main
deb http://security.debian.org/debian-security ${DIST}/updates main
deb-src http://security.debian.org/debian-security ${DIST}/updates main
EOF
	;;
esac

cp -rv --preserve=mode ../2nd-stage-files/pre-2nd-stage-files/* debian
cp -rv --preserve=mode ../2nd-stage-files/pre-2nd-stage-files-${ARCH}/* debian

# Copy ARM emulation stuff
cp -v /usr/bin/qemu-*-static debian/usr/bin || :

# Build a Debian root filesystem (second stage)
chroot debian /bin/sh -e <<- EOF
/debootstrap/debootstrap --second-stage
/bin/mv /tmp/sources.list /etc/apt/sources.list
/usr/bin/apt-get update
/usr/bin/apt-get -y upgrade
/usr/bin/apt-get clean
/bin/rm -rf /var/lib/apt/lists/*
/bin/rm -f /var/log/*.log
/bin/echo root:${PASSWORD} | /usr/sbin/chpasswd
/bin/sed -i "s/#*\s*PermitRootLogin .*/PermitRootLogin yes/" /etc/ssh/sshd_config
EOF

# Remove ARM emulation stuff again
rm -v debian/usr/bin/qemu-*-static || :

cp -rv --preserve=mode ../2nd-stage-files/post-2nd-stage-files/* debian

# List all files
find debian ! -type d -printf "/%P\n" | sort > "/artifacts/debian-${DIST}-${ARCH}.files.txt"

# Make a ext4 filesystem of this and put it into the image
rm -f ext4.img
fallocate -l 900MiB ext4.img
mkfs.ext4 -d debian ext4.img
gzip ext4.img

cp -v ext4.img.gz "${IMAGE2}-${PASSWORD}.bin.gz"