#!/bin/sh

# This script generates FreeBSD images for OpenNebula, being heavily inspired
# from srht's FreeBSD build image definition. It assumes running on a FreeBSD host.
# ZFS installation as documented by the FreeBSD project
# https://wiki.freebsd.org/RootOnZFS/GPTZFSBoot

set -e
set -x

# XXX: Handle command-line arguments?
RELEASE=14.0-RELEASE
ARCH=amd64
IMAGE_PATH_ZFS="freebsd-zfs-$RELEASE-$(date -I).img.qcow2"
IMAGE_PATH_UFS="freebsd-ufs-$RELEASE-$(date -I).img.qcow2"
IMAGE_SIZE=10G

# Comment out to simply use latest version
# Hash checking is disabled when specifying this
#CLOUDSETUP_VERSION=1.2

DIST_BASE="https://download.freebsd.org/ftp/releases/$ARCH/$RELEASE"
ZPOOL=zroot
ZPOOL_TMP="zinstalling"

ZFSTARGET="$(mktemp -d /var/tmp/zfsbuild.XXXXX)"
UFSTARGET="$(mktemp -d /var/tmp/ufsbuild.XXXXX)"

if zpool list -Ho name "$ZPOOL_TMP" 2>/dev/null; then
	echo "The pool $ZPOOL_TMP is already imported." >&2
	exit 1
fi

cleanup() {
	sync ||:
	umount "$UFSTARGET/dev" ||:
	umount "$UFSTARGET/tmp" ||:
	umount "$UFSTARGET/var/tmp" ||:
	umount "$UFSTARGET" ||:
	zpool export "$ZPOOL_TMP" ||:
	mdconfig -du md0 ||:
	mdconfig -du md1 ||:
	rm -rf "$CLOUDSETUP_WORK" ||:
	rmdir "$ZFSTARGET" ||:
	rmdir "$UFSTARGET" ||:
}
trap cleanup EXIT

if [ "$(whoami)" != 'root' ]; then
	echo "This script must be run as root." >&2
	exit 1
fi

if ! command -v rsync >/dev/null
then
	env ASSUME_ALWAYS_YES=YES pkg install -y rsync
fi
if ! command -v qemu-img >/dev/null
then
	env ASSUME_ALWAYS_YES=YES pkg install -y qemu-tools
fi

portsnap fetch
if [ -f /usr/ports/README ]
then
	portsnap update || portsnap extract
else
	portsnap extract
fi

if [ -n "$CLOUDSETUP_VERSION" ]
then
	sed -i .bak -e '/^PORTVERSION=/ s/[0-9]*\.[0-9]*/'"$CLOUDSETUP_VERSION/" /usr/ports/sysutils/firstboot-cloudsetup/Makefile
	make -C /usr/ports/sysutils/firstboot-cloudsetup makesum
fi
make -C /usr/ports/sysutils/firstboot-cloudsetup clean package
CLOUDSETUP_VERSION="$(fgrep VERSION /usr/ports/sysutils/firstboot-cloudsetup/Makefile | cut -f2- | tr -d \\t)"
CLOUDSETUP_PKG="/usr/ports/sysutils/firstboot-cloudsetup/work/pkg/firstboot-cloudsetup-${CLOUDSETUP_VERSION}.pkg"
tar -tzf "$CLOUDSETUP_PKG" >/dev/null # check that it's a valid tar, or we crash due to set -e
# tar -t lists the contents of a tar file, but does not extract

make -C /usr/ports/sysutils/firstboot-freebsd-update clean package
FBUPDATE_VERSION="$(fgrep VERSION /usr/ports/sysutils/firstboot-freebsd-update/Makefile | cut -f2- | tr -d \\t)"
FBUPDATE_PKG="/usr/ports/sysutils/firstboot-freebsd-update/work/pkg/firstboot-freebsd-update-${FBUPDATE_VERSION}.pkg"
tar -tzf "$FBUPDATE_PKG" >/dev/null # check that it's a valid tar, or we crash due to set -e

ufsdisk="$(mktemp /var/tmp/ufsdisk.XXXXX)"
truncate -s 6G "$ufsdisk"
mdconfig -a -t vnode -f "$ufsdisk" -u md1
gpart create -s gpt /dev/md1
#gpart add -t efi -l efiboot0 -s 260M md1
gpart add -t freebsd-boot -l gptboot -b 40 -s 512K md1
gpart bootcode -b /boot/pmbr -p /boot/gptboot -i 1 md1
gpart add -t freebsd-ufs -l rootfs -b 1M -s 5G md1
newfs -U /dev/md1p2

# Mount allocated image.
mount /dev/md1p2 "$UFSTARGET"

# Allocate and partition/format disk image.
# We use "legacy boot", aka BIOS boot
# Preferably, we'd use EFI boot here, check the FreeBSD wiki link in the header
# to see how to make that change, but make the EFI partition larger
zfsdisk="$(mktemp /var/tmp/zfsdisk.XXXXX)"
truncate -s 6G "$zfsdisk"
mdconfig -a -t vnode -f "$zfsdisk" -u md0
gpart create -s gpt /dev/md0
#gpart add -t efi -l efiboot0 -s 260M md1
gpart add -t freebsd-boot -l gptboot0 -b 40 -s 512K md0
gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 md0
gpart add -t freebsd-zfs -l zfs0 -b 1M -s 5G md0
zpool create -O compression=on -o ashift=12 -o "altroot=$ZFSTARGET" -m none -t "$ZPOOL_TMP" "$ZPOOL" md0p2

zfs create -o mountpoint=none                                  "$ZPOOL_TMP/ROOT"
# We set zstd-19 so our image will become smaller, at the cost of a longer build time.
# At the end of the process, we disable zstd-19 again using zfs inherit compression,
# but all files already written will remain zstd-19 compressed
zfs create -o mountpoint=/ -o canmount=noauto                  "$ZPOOL_TMP/ROOT/default"
mount -t zfs "$ZPOOL_TMP/ROOT/default" "$ZFSTARGET"
zpool set "bootfs=$ZPOOL_TMP/ROOT/default" "$ZPOOL_TMP"

zfs create -o mountpoint=/tmp  -o exec=on      -o setuid=off   "$ZPOOL_TMP/tmp"
zfs create -o canmount=off -o mountpoint=/usr                  "$ZPOOL_TMP/usr"
zfs create                                                     "$ZPOOL_TMP/usr/home"
zfs create                     -o exec=off     -o setuid=off   "$ZPOOL_TMP/usr/src"
zfs create -o mountpoint=/usr/ports            -o setuid=off   "$ZPOOL_TMP/usr/ports"
zfs create -o canmount=off -o mountpoint=/var                  "$ZPOOL_TMP/var"
zfs create                     -o exec=off     -o setuid=off   "$ZPOOL_TMP/var/audit"
zfs create                     -o exec=off     -o setuid=off   "$ZPOOL_TMP/var/crash"
zfs create                     -o exec=off     -o setuid=off   "$ZPOOL_TMP/var/log"
zfs create -o atime=on         -o exec=off     -o setuid=off   "$ZPOOL_TMP/var/mail"
zfs create                     -o exec=on      -o setuid=off   "$ZPOOL_TMP/var/tmp"

ln -s /usr/home "$ZFSTARGET/home"
chmod 1777 "$ZFSTARGET/var/tmp"
chmod 1777 "$ZFSTARGET/tmp"

# Download and extract base system.
dist_files="kernel.txz base.txz"
dist_dir="/usr/freebsd-dist/$ARCH/$RELEASE"

mkdir -p "$dist_dir"
for f in $dist_files
do
	fetch -m -o "$dist_dir/$f" "$DIST_BASE/$f"
	tar -C "$UFSTARGET" -xJf "$dist_dir/$f"
done

# Mount dev and tmp in chroot
mount -t devfs devfs "$UFSTARGET/dev"
mount_nullfs /tmp "$UFSTARGET/tmp"
mount_nullfs /var/tmp "$UFSTARGET/var/tmp"

# Install the first-boot script that configures the network and ssh key
# We must use --rootdir and not --chroot, because the file is read from within the chroot
# --automatic means that the package is considered to be installed "automatically",
# aka as a dependency of something, so pkg autoremove will remove it.
# We do not run pkg autoremove ourselves, that's up to the administrator.
pkg --rootdir "$UFSTARGET" add --automatic "$CLOUDSETUP_PKG" "$FBUPDATE_PKG"

# Configure new system.
touch "$UFSTARGET/firstboot"
sysrc -f "$UFSTARGET/boot/loader.conf" \
	zfs_load="YES" \
	autoboot_delay="-1" \

sysrc -f "$UFSTARGET/etc/rc.conf" \
	zfs_enable="YES" \
	ntpd_enable="YES" \
	sshd_enable="YES" \
	growfs_enable="YES" \
	hostname="freebsd" \
	firstboot_cloudsetup_enable="YES" \
	firstboot_freebsd_update_enable="YES" \

# The resolv.conf file is written by firstboot_cloudsetup
#cp /etc/resolv.conf "$UFSTARGET/etc/resolv.conf"

tzsetup -s -C "$UFSTARGET" UTC

# Add PermitRootLogin without-password, unless PermitRootLogin yes was already set
sed -i .orig -e '/^#PermitRootLogin[[:blank:]]/a\
PermitRootLogin without-password
' -e '/^PermitRootLogin[[:blank:]]*no/ s/\([[:blank:]]\).*$/\1without-password/' \
	"$UFSTARGET/etc/ssh/sshd_config"
if ! grep -Eq '^PermitRootLogin (without-password|yes)' "$UFSTARGET/etc/ssh/sshd_config"
then
	cat >>"$UFSTARGET/etc/ssh/sshd_config" <<EOF

# Added by Ungleich
PermitRootLogin without-password
EOF
fi

# Set zstd-19 compression, copy all data to the pool, and then set compression to default again
# This will make the base image smaller, at the cost of taking longer to generate, as zstd-19 is slow to write
# Therefore, afterwards we restore compression to default, so written files stay zstd-19, which is fast to read,
# but files written by the user afterwards will be written with the default compression algorihtm.
zfs set compression=zstd-19 "$ZPOOL_TMP/ROOT/default"
umount "$UFSTARGET/dev" "$UFSTARGET/tmp" "$UFSTARGET/var/tmp"
rsync -aH --fileflags --inplace "$UFSTARGET/." "$ZFSTARGET"

sysrc -f "$UFSTARGET/boot/loader.conf" -x zfs_load
sysrc -f "$UFSTARGET/etc/rc.conf" -x zfs_enable
printf '# Device\tMountpoint\tFStype\tOptions\t\tDump\tPass#\n' \
	>"$ZFSTARGET/etc/fstab"
printf '# Device\tMountpoint\tFStype\tOptions\t\tDump\tPass#\n%s\t%s\t\t%s\t%s\t%s\t%s\n' \
	/dev/gpt/rootfs / ufs rw,noatime 1 1 \
	>"$UFSTARGET/etc/fstab"
sync ||:
zfs inherit compression "$ZPOOL_TMP/ROOT/default"

trap : EXIT
cleanup

mkdir -p "$ARCH"
qemu-img convert -f raw -O qcow2 "$zfsdisk" "$ARCH/$IMAGE_PATH_ZFS"
qemu-img convert -f raw -O qcow2 "$ufsdisk" "$ARCH/$IMAGE_PATH_UFS"
rm "$zfsdisk" "$ufsdisk"

# Filesystem will be enlarged by growfs(7) on next startup
qemu-img resize "$ARCH/$IMAGE_PATH_ZFS" "$IMAGE_SIZE"
qemu-img resize "$ARCH/$IMAGE_PATH_UFS" "$IMAGE_SIZE"