setup-disk.in

#!/bin/sh

PREFIX=
. "$PREFIX/lib/libalpine.sh"

MBR=${MBR:-"/usr/share/syslinux/mbr.bin"}

in_list() {
	local i="$1"
	shift
	while [ $# -gt 0 ]; do
		[ "$i" = "$1" ] && return 0
		shift
	done
	return 1
}

# wrapper to only show given device
_blkid() {
	blkid | grep "^$1:"
}

# if given device have an UUID display it, otherwise return the device
uuid_or_device() {
	local i=
	case "$1" in
		/dev/md*) echo "$1" && return 0;;
	esac
	for i in $(_blkid "$1"); do
		case "$i" in
			UUID=*) eval $i;;
		esac
	done
	if [ -n "$UUID" ]; then
		echo "UUID=$UUID"
	else
		echo "$1"
	fi
}

# generate an fstab from a given mountpoint. Convert to UUID if possible
enumerate_fstab() {
	local mnt="$1"
	local fs_spec= fs_file= fs_vfstype= fs_mntops= fs_freq= fs_passno=
	[ -z "$mnt" ] && return
	local escaped_mnt=$(echo $mnt | sed 's:/:\\/:g')
	awk "\$2 ~ /^$escaped_mnt/ {print \$0}" /proc/mounts | \
		sed "s:$mnt:/:g; s: :\t:g" | sed 's:/\+:/:g' | \
		while read fs_spec fs_file fs_vfstype fs_mntops fs_freq fs_passno; do
			echo -e "$(uuid_or_device $fs_spec)\t${fs_file}\t${fs_vfstype}\t${fs_mntops} ${fs_freq} ${fs_passno}"
		done
}

is_vmware() {
	grep -q VMware /proc/scsi/scsi 2>/dev/null \
		|| grep -q VMware /proc/ide/hd*/model 2>/dev/null
}

is_xen() {
	[ -d /proc/xen ]
}

# return true (0) if given device is lvm
is_lvm() {
	lvs "$1" >/dev/null 2>&1
}

# Find the disk device from given partition
disk_from_part() {
	# we need convert cciss/c0d0* cciss!c0d0*...
	local i= part=$(echo ${1#/dev/} | sed 's:/:!:g')
	for i in /sys/block/*/$part; do
		i=${i%/*}
		# ...and back from cciss!c0d0 to cciss/c0d0
		if [ -b "/dev/${i##*/}" ]; then
			echo "/dev/${i##*/}" | sed 's:!:/:g'
			return 0
		fi
	done
	return 1
}

unpack_apkovl() {
	local ovl="$1"
	local dest="$2"
	local suffix=${ovl##*.}
	local i
	ovlfiles=/tmp/ovlfiles
	if [ "$suffix" = "gz" ]; then
		if ! tar -C "$dest" --numeric-owner -zxvf "$ovl" > $ovlfiles; then
			echo -n "Continue anyway? [Y/n]: "
			read i
			case "$i" in
				n*|N*) return 1;;
			esac
		fi
		return 0 
	fi

	apk add -q openssl

	if ! openssl list-cipher-commands | grep "^$suffix$" > /dev/null; then
		errstr="Cipher $suffix is not supported"
		return 1
	fi
	local count=0
	# beep
	echo -e "\007"
	while [ $count -lt 3 ]; do
		openssl enc -d -$suffix -in "$ovl" | tar --numeric-owner \
			-C "$dest" -zxv >$ovlfiles 2>/dev/null && return 0
		count=$(( $count + 1 ))
	done
	ovlfiles=
	return 1
}

# find filesystem of given mounted dir
find_mount_fs() {
	local mount_point="$1"
	awk "\$2 == \"$mount_point\" {print \$3}" /proc/mounts | tail -n 1
}

# find device for given mounted dir
find_mount_dev() {
	local mnt="$1"
	awk "\$2 == \"$mnt\" { print \$1 }" /proc/mounts | tail -n 1
}

supported_boot_fs() {
	local supported="ext2 ext3 ext4 btrfs"
	local fs=
	for fs in $supported; do
		[ "$fs" = "$1" ] && return 0
	done
	echo "$1 is not supported. Only supported are: $supported" >&2
	return 1
}

install_mounted_root() {
	local mnt="$1" mnt_boot="$1" boot_fs= root_fs=
	local initfs_features="ata base ide scsi usb virtio"

	rootdev=$(find_mount_dev "$mnt")
	if [ -z "$rootdev" ]; then
		echo "$mnt does not seem to be a mount point" >&2
		return 1
	fi
	root_fs=$(find_mount_fs "$mnt")
	initfs_features="$initfs_features $root_fs"

	if is_lvm "$rootdev"; then
		initfs_features="$initfs_features lvm"
	fi


	bootdev=$(find_mount_dev "$mnt"/boot)
	if [ -z "$bootdev" ]; then
		bootdev=$rootdev
	else
		mnt_boot="$mnt"/boot
		bootdev=$(find_mount_dev "$mnt_boot")
	fi
	boot_fs=$(find_mount_fs "$mnt_boot")
	supported_boot_fs "$boot_fs" || return 1

	mbrdisk=$(disk_from_part $bootdev)
	if [ -e "/sys/block/${rootdev#/dev/}/md" ]; then
		local md=${rootdev#/dev/}
		initfs_features="$initfs_features raid"
		raidmod=$(cat /sys/block/$md/md/level)
		raidmod=",$raidmod"
		raidopt="-r"
		# get a list of slaves
		mbrdisk=
		for i in /sys/block/$md/slaves/*; do
			j=${i##*/}
			i=${j%[0-9]*}
			if [ -b "/dev/$i" ]; then
				mbrdisk="$mbrdisk /dev/${i}"
			fi
		done
	fi
	if [ -n "$VERBOSE" ]; then
		echo "Root device:     $rootdev"
		echo "Root filesystem: $root_fs"
		echo "Boot device:     $bootdev"
		echo "Boot filesystem: $boot_fs"
		echo "MBR disk(s):    $mbrdisk"
	fi

	if [ -z "$APKOVL" ]; then
		ovlfiles=/tmp/ovlfiles
		lbu package - | tar -C "$mnt" -zxv > "$ovlfiles"
	else
		echo "Restoring backup from $APKOVL to $rootdev..."
		unpack_apkovl "$APKOVL" "$mnt" || return 1
	fi

	# generate mkinitfs.conf
	mkdir -p "$mnt"/etc/mkinitfs
	echo "features=\"$initfs_features\"" > "$mnt"/etc/mkinitfs/mkinitfs.conf

	# generate the fstab
	if [ -f "$mnt"/etc/fstab ]; then
		mv "$mnt"/etc/fstab "$mnt"/etc/fstab.old
	fi
	enumerate_fstab "$mnt" >> "$mnt"/etc/fstab
	cat >>"$mnt"/etc/fstab <<EOF
/dev/cdrom	/media/cdrom	iso9660	noauto,ro 0 0
/dev/fd0	/media/floppy	vfat	noauto	0 0
/dev/usbdisk	/media/usb	vfat	noauto	0 0
EOF

	# remove the installed db in case its there so we force re-install
	rm -f "$mnt"/var/lib/apk/installed
	echon "Installing system on $rootdev: "
	# apk reads config from target root so we need to copy the config
	mkdir -p "$mnt"/etc/apk/keys/
	cp /etc/apk/keys/* "$mnt"/etc/apk/keys/


	local apkflags="--quiet --progress --update-cache --clean-protected"
	local pkgs=$(cat "$mnt"/var/lib/apk/world)
	pkgs="$pkgs acct linux-$KERNEL_FLAVOR alpine-base"
	local repos=$(sed -e 's/\#.*//' /etc/apk/repositories)
	local repoflags=
	for i in $repos; do
		repoflags="$repoflags --repository $i"
	done
	
	apk add --root "$mnt" $apkflags --overlay-from-stdin \
		$repoflags $pkgs <$ovlfiles>/dev/null || return 1
	echo ""

	# make things bootable
	if is_vmware; then
		pax_nouderef="pax_nouderef "
	else
		pax_nouderef=
	fi

	if is_xen; then
		# create a menu.lst
		mkdir -p "$mnt"/boot/grub
		cat >"$mnt"/boot/grub/menu.lst <<EOF
default 0
title $KERNEL_FLAVOR
root (hd0,0)
kernel /boot/$KERNEL_FLAVOR root=$(uuid_or_device $rootdev) modules=${root_fs}${raidmod} quiet xen BOOT_IMAGE=/boot/$KERNEL_FLAVOR
initrd=/boot/initramfs-$KERNEL_FLAVOR
EOF
	else
		# create an extlinux.conf
		cat >"$mnt"/boot/extlinux.conf <<EOF
timeout 20
prompt 1
default $KERNEL_FLAVOR
label $KERNEL_FLAVOR
	kernel /boot/vmlinuz-$KERNEL_FLAVOR
	append initrd=/boot/initramfs-$KERNEL_FLAVOR root=$(uuid_or_device $rootdev) modules=sd-mod,usb-storage,${root_fs}${raidmod} ${pax_nouderef}quiet
EOF
	fi

	# install extlinux
	apk add -q syslinux
	is_xen || extlinux -i $raidopt "$mnt"/boot/
}

unmount_partitions() {
	local mnt="$1"

	# unmount the partitions
	umount $(awk '{print $2}' /proc/mounts | grep ^"$mnt" | sort -r)
}

fix_mbr_all_disks() {
	# fix mbr for all disk devices
	for i in $mbrdisk; do
		local errmsg
		echo "Writing MBR to $i"
		errmsg=$(dd if="$MBR" of=$i 2>&1) \
			|| echo "$errmsg"
	done
}

# figure out decent default swap size in mega bytes
find_swap_size() {
	local memtotal_kb=$(awk '$1 == "MemTotal:" {print $2}' /proc/meminfo)
	# use 2 * avaiable ram
	echo $(( $memtotal_kb * 2 / 1024 ))
}

has_mounted_part() {
	local p
	# parse /proc/mounts for mounted devices
	for p in $(awk '$1 ~ /^\/dev\// {gsub("/dev/", "", $1); print $1}' \
			/proc/mounts); do
		[ "$p" = "$1" ] && return 0
		[ -e /sys/block/$1/$p ] && return 0
	done
	return 1
}

has_holders() {
	local i
	# check if device is used by any md devices
	for i in $1/holders/* $1/*/holders/*; do
		[ -e "$i" ] && return 0
	done
	return 1
}

is_available_disk() {
	local dev=$1
	local b=$(echo $p | sed 's:/:!:g')

	# check if its a "root" block device and not a partition
	[ -e /sys/block/$b ] || return 1
	
	# check so it does not have mounted partitions
	has_mounted_part $dev && return 1

	# check so its not part of an md setup
	if has_holders /sys/block/$b; then
		[ -n "$USE_RAID" ] && echo "Warning: $dev is part of a running raid" >&2
		return 1
	fi

	# check so its not an md device
	[ -e /sys/block/$b/md ] && return 1

	return 0
}

find_disks() {
	local p=
	for p in $(awk '$1 ~ /[0-9]+/ {print $4}' /proc/partitions); do
		is_available_disk $p && echo -n " $p"
	done
}

native_disk_install() {
	local rootdisk_dev="$1"
	local i size
	local boot_size=100 boot_part_type="83" 
	local swap_size=$(find_swap_size) swap_part_type="82"
	local root_part_type="83"
	local raidpkg= partitions=
	local minimum_root_size=$(($boot_size * 2))
	local rootfs=ext4 bootfs=ext4

	if [ -n "$USE_RAID" ]; then
		boot_part_type="fd"
		swap_part_type="fd"
		root_part_type="fd"
		raidpkg="mdadm"
	fi

	dmesg -n1
	apk_add -q sfdisk e2fsprogs $raidpkg || return 1
	local root_size=$(( $(sfdisk -s $rootdisk_dev) / 1024 - $swap_size - $boot_size))
	if [ "$root_size" -lt "$minimum_root_size" ]; then
		echo "The $rootdisk_dev is too small. At least $(( $boot_size + $swap_size + $minimum_root_size)) is needed." >&2
		return 1
	fi

	echo ""
	echo "Creating the following partitions on $rootdisk_dev:"
	echo " /boot	${boot_size}MB"
	echo " swap	${swap_size}MB"
	echo " /	${root_size}MB"
	echo ""
	if [ -n "$APKOVL" ]; then
		echo "System from $APKOVL will be restored"
	fi
	echo -n "WARNING: All contents of $rootdisk_dev will be erased. Continue? [y/N]: "
	read i
	case "$i" in
		y*|Y*);;
		*) return 1;;
	esac
	
	echo "Initializing partitions..."
	if [ -n "$USE_RAID" ]; then
		local rd
		for rd in md0 md1 md2; do
			[ -b /dev/$rd ] && mdadm --stop /dev/$rd
		done
	fi

	# new disks does not have an DOS signature in sector 0
	# this makes sfdisk complain. We can workaround this by letting
	# fdisk create that DOS signature, by just do a "w", a write.
	# http://bugs.alpinelinux.org/issues/show/145
	echo "w" | fdisk $rootdisk_dev >/dev/null

	# create new partitions
	(cat <<EOF
0,$boot_size,$boot_part_type,*
,$swap_size,$swap_part_type
,,$root_part_type
EOF
	) | sfdisk -q -L -uM $rootdisk_dev >>/tmp/sfdisk.out || return 1

	# create device nodes if not exist
	mdev -s

	if [ -n "$USE_RAID" ]; then
		local p= rd=
		for p in $(sfdisk -l $rootdisk_dev 2>/dev/null \
				| awk '/Linux raid/ {print $1}'); do
			local opt="--metadata=0.90"
			case "$p" in
				*1) rd=/dev/md0; boot_dev=/dev/md0;;
				*2) rd=/dev/md1; swap_dev=/dev/md1
				    opt= ;;
				*3) rd=/dev/md2; root_dev=/dev/md2;;
			esac
			mdadm --create $rd --level=1 --raid-devices=2 \
				$opt --quiet --run $p missing
		done
	else
		local p=
		for p in $(sfdisk -l $rootdisk_dev 2>/dev/null \
				| awk '$1 ~ /^\/dev/ {print $1}'); do
			case "$p" in
				*1) boot_dev=$p;;
				*2) swap_dev=$p;;
				*3) root_dev=$p;;
			esac
		done
	fi
	mkfs.$bootfs -q $boot_dev >/dev/null \
		&& mkswap $swap_dev >/dev/null \
		&& mkfs.$rootfs -q >/dev/null $root_dev \
		|| return 1

	mkdir -p /mnt
	mount -t $rootfs $root_dev /mnt || return 1
	mkdir -p /mnt/boot
	mount -t $bootfs $boot_dev /mnt/boot || return 1
	if [ -n "$USE_RAID" ]; then
		mdadm --detail --scan > /etc/mdadm.conf
		rc-update --quiet add mdadm-raid boot
	fi

	# manually add swap to local fstab and swapon (in case the install needs swap)
	sed -i -e '/swap/d' /etc/fstab
	echo -e "$(uuid_or_device $swap_dev)\tswap\t\tswap\tdefaults 0 0" >> /etc/fstab
	swapon -a

	install_mounted_root /mnt || return 1

	# manually add swap to mounted fstab and add the swap service to the boot runlevel
	echo -e "$(uuid_or_device $swap_dev)\tswap\t\tswap\tdefaults 0 0" >> /mnt/etc/fstab
	chroot /mnt rc-update --quiet add swap boot
	chroot /mnt rc-update --quiet add urandom boot

	unmount_partitions /mnt
	swapoff -a
	fix_mbr_all_disks

	echo ""
	echo "Installation is done. Please reboot."
	apk del -q syslinux
}

data_only_disk_install() {
	echo "TODO: $1"
}

usage() {
	cat <<__EOF__
usage: setup-disk [-hr] [-k kernelflavor] [-o apkovl] [MOUNTPOINT]

Install alpine on harddisk.

options:
 -h  Show this help
 -o  Restore system from given apkovl file
 -k  Use kernelflavor instead of $KERNEL_FLAVOR
 -r  Enable software raid1 with single disk

__EOF__
	exit 1
}

diskselect_help() {
	cat <<__EOF__

TODO

__EOF__
}

diskmode_help() {
	cat <<__EOF__

TODO

__EOF__
}

# ask for a root or data disk
# returns answer in global variable $answer
ask_disk() {
	local prompt="$1"
	local help_func="$2"
	shift 2
	answer=

	while ! in_list "$answer" $@ "none" "abort"; do
		echo "Available disks are: $@"
		echon "$prompt [$1] "
		default_read answer $1
		case "$answer" in
			'abort') exit 0;;
			'none') return 0;;
			'?') $help_func;;
			*) if ! [ -b "/dev/$answer" ]; then
				echo "/dev/$answer is not a block device" >&2
				answer=
			   fi;;
		esac
	done
}

KERNEL_FLAVOR=grsec
case "$(uname -r)" in
	*-vs[0-9]*) KERNEL_FLAVOR=vserver;;
	*-pae) KERNEL_FLAVOR=pae;;
esac

# Parse args
while getopts "hk:o:rv" opt; do
	case $opt in
		k) KERNEL_FLAVOR="$OPTARG";;
		r) USE_RAID=1;;
		o) APKOVL="$OPTARG";;
		v) VERBOSE=1;;
		*) usage;;
	esac
done
shift $(( $OPTIND - 1))

if [ -d "$1" ]; then
	# install to given mounted root
	install_mounted_root "${1%/}"
	exit $?
fi

disks=$(find_disks)
disk=none

# no disks so lets exit quietly.
[ -z "$disks" ] && exit 0

if [ $# -gt 0 ]; then
	# check that they are 
	for i in "$@"; do
		j=$(readlink -f "$i" | sed 's:^/dev/::; s:/:!:g')
		if ! [ -e "/sys/block/$j/device" ]; then
			echo "$i is not a suitable for partitioning"
			exit 1
		fi
	done
	disk=${1##/dev/}
else
	ask_disk "Which disk would you like to use? (or '?' for help or 'none')" \
		diskselect_help $disks
	disk=$answer
fi

diskmode=
if [ "$disk" != none ]; then
	answer=
	while true; do
		echon "How would you like to use $disk? ('root', 'data' or '?' for help) [?] "
		default_read answer '?'
		case "$answer" in
		'?') diskmode_help;;
		root|data) break;;
		esac
	done
	diskmode="$answer"
fi


# native disk install
case "$diskmode" in
root) native_disk_install /dev/$disk;;
data) data_only_disk_install /dev/$disk;;
esac