0-preinstall.sh

#!/usr/bin/env bash
#-------------------------------------------------------------------------
# Arch Hodag Install Script, Based in Chris Titus's very excellent
# ArchTitus script. I have forked his project and tweaked it to meet
# my personal needs.
#-------------------------------------------------------------------------
SCRIPT_DIR="$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
echo "-------------------------------------------------"
echo "Setting up mirrors for optimal download          "
echo "-------------------------------------------------"
iso=$(curl -4 ifconfig.co/country-iso)
timedatectl set-ntp true
pacman -S --noconfirm pacman-contrib terminus-font
setfont ter-v22b
sed -i 's/^#Para/Para/' /etc/pacman.conf

#Enable ChaoticAUR for initial install
pacman-key --recv-key 3056513887B78AEB --keyserver keyserver.ubuntu.com
pacman-key --lsign-key 3056513887B78AEB
pacman -U --noconfirm 'https://cdn-mirror.chaotic.cx/chaotic-aur/chaotic-keyring.pkg.tar.zst' 'https://cdn-mirror.chaotic.cx/chaotic-aur/chaotic-mirrorlist.pkg.tar.zst'
echo "[chaotic-aur]" >> /etc/pacman.conf
echo "Include = /etc/pacman.d/chaotic-mirrorlist" >> /etc/pacman.conf
echo -e "\nInstalling Base System\n" >> /etc/pacman.conf
pacman -Sy --noconfirm

pacman -S --noconfirm reflector rsync grub
mv /etc/pacman.d/mirrorlist /etc/pacman.d/mirrorlist.backup

echo -e "-------------------------------------------------------------------------"
echo -e "-Setting up $iso mirrors for faster downloads"
echo -e "-------------------------------------------------------------------------"

reflector -a 48 -c $iso -f 5 -l 20 --sort rate --save /etc/pacman.d/mirrorlist
mkdir /mnt


echo -e "\nInstalling prereqs...\n$HR"
pacman -S --noconfirm gptfdisk btrfs-progs

echo "-------------------------------------------------"
echo "-------select your disk to format----------------"
echo "-------------------------------------------------"
lsblk
echo "Please enter disk to work on: (example /dev/sda)"
read DISK
echo "THIS WILL FORMAT AND DELETE ALL DATA ON THE DISK"
read -p "are you sure you want to continue (Y/N):" formatdisk
case $formatdisk in

y|Y|yes|Yes|YES)
echo "--------------------------------------"
echo -e "\nFormatting disk...\n$HR"
echo "--------------------------------------"

# disk prep
sgdisk -Z ${DISK} # zap all on disk
sgdisk -a 2048 -o ${DISK} # new gpt disk 2048 alignment

# create partitions
sgdisk -n 1::+1M --typecode=1:ef02 --change-name=1:'BIOSBOOT' ${DISK} # partition 1 (BIOS Boot Partition)
sgdisk -n 2::+100M --typecode=2:ef00 --change-name=2:'EFIBOOT' ${DISK} # partition 2 (UEFI Boot Partition)
sgdisk -n 3::-0 --typecode=3:8300 --change-name=3:'ROOT' ${DISK} # partition 3 (Root), default start, remaining
if [[ ! -d "/sys/firmware/efi" ]]; then
    sgdisk -A 1:set:2 ${DISK}
fi

# make filesystems
echo -e "\nCreating Filesystems...\n$HR"
if [[ ${DISK} =~ "nvme" ]]; then
mkfs.vfat -F32 -n "EFIBOOT" "${DISK}p2"
mkfs.btrfs -L "ROOT" "${DISK}p3" -f
mount -t btrfs "${DISK}p3" /mnt
else
mkfs.vfat -F32 -n "EFIBOOT" "${DISK}2"
mkfs.btrfs -L "ROOT" "${DISK}3" -f
mount -t btrfs "${DISK}3" /mnt
fi
ls /mnt | xargs btrfs subvolume delete
btrfs subvolume create /mnt/@
umount /mnt
;;
*)
echo "Rebooting in 3 Seconds ..." && sleep 1
echo "Rebooting in 2 Seconds ..." && sleep 1
echo "Rebooting in 1 Second ..." && sleep 1
reboot now
;;
esac

# mount target
mount -t btrfs -o subvol=@ -L ROOT /mnt
mkdir /mnt/boot
mkdir /mnt/boot/efi
mount -t vfat -L EFIBOOT /mnt/boot/

if ! grep -qs '/mnt' /proc/mounts; then
    echo "Drive is not mounted can not continue"
    echo "Rebooting in 3 Seconds ..." && sleep 1
    echo "Rebooting in 2 Seconds ..." && sleep 1
    echo "Rebooting in 1 Second ..." && sleep 1
    reboot now
fi

echo "--------------------------------------"
echo "-- Arch Install on Main Drive       --"
echo "--------------------------------------"
pacstrap /mnt base base-devel linux linux-firmware vim nano sudo archlinux-keyring wget libnewt --noconfirm --needed
genfstab -U /mnt >> /mnt/etc/fstab
echo "keyserver hkp://keyserver.ubuntu.com" >> /mnt/etc/pacman.d/gnupg/gpg.conf
cp -R ${SCRIPT_DIR} /mnt/root/ArchHodag
cp /etc/pacman.d/mirrorlist /mnt/etc/pacman.d/mirrorlist
echo "--------------------------------------"
echo "-- Check for low memory systems <16G --"
echo "--------------------------------------"
TOTALMEM=$(cat /proc/meminfo | grep -i 'memtotal' | grep -o '[[:digit:]]*')
if [[  $TOTALMEM -lt 16323861 ]]; then
    #Put swap into the actual system, not into RAM disk, otherwise there is no point in it, it'll cache RAM into RAM. So, /mnt/ everything.
    echo "Creating 16GB Swapfile"
    mkdir /mnt/opt/swap #make a dir that we can apply NOCOW to to make it btrfs-friendly.
    chattr +C /mnt/opt/swap #apply NOCOW, btrfs needs that.
    dd if=/dev/zero of=/mnt/opt/swap/swapfile bs=1M count=16384 status=progress
    chmod 600 /mnt/opt/swap/swapfile #set permissions.
    chown root /mnt/opt/swap/swapfile
    mkswap /mnt/opt/swap/swapfile
    swapon /mnt/opt/swap/swapfile
    #The line below is written to /mnt/ but doesn't contain /mnt/, since it's just / for the sysytem itself.
    echo "/opt/swap/swapfile	none	swap	sw	0	0" >> /mnt/etc/fstab #Add swap to fstab, so it KEEPS working after installation.
fi
echo "--------------------------------------"
echo "--   SYSTEM READY FOR 0-setup       --"
echo "--------------------------------------"