#!/bin/bash
set -o errexit
set -o pipefail
set -o nounset
set -x
 
# Le script suppose que / est sur /boot est sur /dev/md2, / est sur
# /dev/md3 et que /home est sur /dev/md4
# Enfin un fstab est généré, lvm2 est installé, grub et le kernel
# sont réinstallés.

export LC_ALL=C
swapoff -a
cd /mnt
mkdir -p root_in_ram rootfs home var usr log
mount -t tmpfs none /mnt/root_in_ram -o size=90%
mount /dev/md3 /mnt/rootfs/
rsync -a /mnt/rootfs/ /mnt/root_in_ram/
umount /mnt/rootfs
# Change LABEL for /boot, yeah 2 times, IDK why but the first time is not applied Oo
mdadm --stop /dev/md4
mdadm --stop /dev/md3
tune2fs -LBOOT /dev/md2 && tune2fs -LBOOT /dev/md2
# Check if label is BOOT
wipefs /dev/md2


mdadm --stop /dev/md2
parted -s /dev/sda rm 5
parted -s /dev/sda rm 4
parted -s /dev/sda rm 3
# /
parted -a optimal -s /dev/sda mkpart primary ext4 1073M 2073M
sleep 2
parted -s /dev/sda set 3 raid on
# /var
parted -a minimal -s /dev/sda mkpart primary ext4 2073M 12073M
sleep 2
parted -s /dev/sda set 4 raid on
# /usr
parted -a minimal -s /dev/sda mkpart primary ext4 12073M 17073M
sleep 2
parted -s /dev/sda set 5 raid on
# LVM
parted -a minimal -s /dev/sda mkpart primary ext4 17073M 100%
parted -s /dev/sda set 6 raid on
sleep 2

partprobe /dev/sda

for disk in {b,c,d,e,f}; do
	sgdisk -R=/dev/sd${disk} /dev/sda
	sgdisk -G /dev/sd${disk}
	partprobe /dev/sd${disk}
done

mdadm --assemble /dev/md2 /dev/{sda,sdb,sdc,sdd,sde,sdf}2

# RAID1 for systems.
# Metadata 0.90 as some OVH kernel need it to boot.
for part in {3,4,5}; do
    mdadm --create /dev/md${part} --metadata=0.90 --level=raid1 --raid-devices=6 /dev/{sda,sdb,sdc,sdd,sde,sdf}${part}
done

# No need for LVM part to have metadata 0.90.
mdadm --create /dev/md/b6 --level=5 --raid-devices=3 /dev/sd{a,b,c}6
mdadm --create /dev/md/c6 --level=5 --raid-devices=3 /dev/sd{d,e,f}6
mdadm --create /dev/md/a6 --level=0 --raid-devices=2 /dev/md/b6 /dev/md/c6

mkfs.ext4 -LROOTFS /dev/md3 >/dev/null
mkfs.ext4 -LVAR /dev/md4 >/dev/null
mkfs.ext4 -LUSR /dev/md5 >/dev/null

# Add LVM with a VG for all of the free space.
pvcreate /dev/md125
vgcreate vg0 /dev/md125
lvcreate --size 1G --name tmp vg0
mkfs.ext4 -LTMP /dev/mapper/vg0-tmp >/dev/null
lvcreate --size 512M --name swap1 vg0
lvcreate --size 512M --name swap2 vg0
mkswap -f -LSWAP1 /dev/mapper/vg0-swap1
mkswap -f -LSWAP2 /dev/mapper/vg0-swap2
lvcreate --size 10G --name home vg0
mkfs.ext4 -LHOME /dev/mapper/vg0-home >/dev/null
lvcreate --extents 95%FREE --name backup vg0
mkfs.btrfs -LBACKUP /dev/vg0/backup

# Copy data from RAM.
mount -LROOTFS rootfs
mount -LHOME home
mount -LVAR var
mount -LUSR usr
rsync -a root_in_ram/home/ home/
rsync -a root_in_ram/var/ var/
rsync -a root_in_ram/usr/ usr/
rsync -a \
    --exclude="home/**" \
    --exclude="var/**" \
    --exclude="usr/**" \
    root_in_ram/ rootfs/
umount home var usr

# Generate fstab.
cat <<EOT>rootfs/etc/fstab
LABEL=ROOTFS /         ext4  errors=remount-ro 0 1
LABEL=BOOT   /boot     ext4  defaults 0 2
LABEL=EFI_SYSPART /boot/efi   vfat   defaults 0 2
LABEL=HOME   /home     ext4  defaults 0 2
LABEL=TMP    /tmp      ext4  defaults 0 2
LABEL=USR    /usr      ext4  defaults 0 2
LABEL=VAR    /var      ext4  defaults 0 2
#LABEL=BACKUP /backup   btrfs defaults 0 2
LABEL=SWAP1  none      swap  sw 0 0
LABEL=SWAP2  none      swap  sw 0 0
EOT

mount -t proc none /mnt/rootfs/proc
mount -o bind /dev /mnt/rootfs/dev
mount -o bind /dev/pts /mnt/rootfs/dev/pts
mount -t sysfs sys /mnt/rootfs/sys
mount --bind /run /mnt/rootfs/run
rm -rf /mnt/rootfs/boot/*
# Chroot and install lvm2 + reconfigure grub-pc
echo "Evolix partitioning done... Follow instrutions in projet6140(8) then reboot!"