script to install Arch Linux

arch-install.sh

#!/bin/bash

## Assumes ##
# Working internet connection
# Pre-installation work already done

## Instructions ##
# After booting into Arch ISO, run:
# curl -sL https://git.io/JexlX | /bin/bash
# and follow the instructions on the script.
# You can always Ctrl-C to interrupt the script.


## Safer Bash Scripting ###
set -euo pipefail #e: exits immediatly if failure, u:exit if using unset variables, o pipefail: if using pipeline, will exit where it failed since if not set, it would have still gone on to the last command even if prev command failed,  
#set -x #shows the actually bash command before executing it(verbose)
trap 's=$?; echo "$0: Error on line "$LINENO": $BASH_COMMAND"; exit $s' ERR #trap catches signals and execute code when they appear, on error, the echo command is called and ERR is the type error that trap catches

### Set up logging ###
exec 1> >(tee "stdout.log")
exec 2> >(tee "stderr.log")

### Start of Installer ###

printf "Welcome to my awesome Arch Installer. This script assumes a network is already configured.\n\n 0 - default partion scheme using ext4 fs(needs atleast 40.5 GB of storage): 260MiB /boot, 30GB root, 10GB swap, remaining space home;\n 1 - custom installation\n\nNOTE: If you have UEFI, systemd-boot will be installed. If you have BIOS, GRUB will be installed. Please modify the script to change the bootloader.\n\nHow would you like to install Arch? [0/1] "
read method < /dev/tty #must specific input from current tty otherwise will take stdin from other sources such as pipes

## default ##
if [ ${method:-0} -eq 0 ]; then

	devicelist=$(lsblk -dplnx size -o name,size | grep -Ev "boot|rpmb|loop" | tac) #list devices of only their name and size, excluding non disks, tac prints in rev order
	device=$(dialog --stdout --menu "Select disk to install to" 0 0 0 ${devicelist}) || exit 1 #redirect output to stdout to variable, if unsuccessful command exit 1

	hostname=$(dialog --stdout --inputbox "Enter hostname" 0 0) || exit 1; #if LHS unsuccess, will exit with error 1, must put semicolon to clear properly, also needs backslash for properly reading inner variables
	clear; 	# don't forget semicolon
	: ${hostname:?"hostname cannot be empty"}

	password=$(dialog --stdout --passwordbox "Enter admin password" 0 0) || exit 1; #setting root password
	clear;
	: ${password:?"password cannot be empty"}
	password2=$(dialog --stdout --passwordbox "Enter admin password again" 0 0) || exit 1;
	clear;
	[[ "$password" == "$password2" ]] || ( echo "Passwords did not match"; exit 1; )

	timedatectl set-ntp true

#echo "Would you like to modify the keyboard layout? (y/n)" #***needs to be fixed
#read method2 < /dev/tty
#if [ "$method2" == "y" ] || [ "$method2" == "Y" ]; then
#localectl list-keymaps # list possible layouts
#localectl status 	# current layout
#echo "Scroll back the see the options. The current keyboard settings are shown above"
#echo "Please enter a choice from the list of keymaps"
#read keymap < /dev/tty
#loadkeys $keymap 		# switch the layout to us
#: ${keymap:?"Can not be empty"}
#fi

if [ -d /sys/firmware/efi/efivars/ ]; then #for uefi
	echo "Creating UEFI boot";

	cpu=$(dialog --stdout --menu "Select your CPU type" 0 0 0 Intel "" AMD "") || exit 1
	if [ cpu == Intel ]; then
		cpu=intel;
	else
		cpu=amd;
	fi

	#no user intervention, use chosen device, end of command options, make gpt type 
	#efi boot partition **MUST BE fat32 WHEN USING GNU PARTED** recommended size of 260MiB 
	#flag the partition that contains the /boot directory as bootable
	#root partition taking 30G
	#swap partition matching the 10GB of ram
	#home partition taking rest of space
	#***IMPORTANT*** can not have spaces after backslash! or else will not run properly
	parted --script "${device}" -- mklabel gpt \
		mkpart ESP fat32 1MiB 261MiB \
		set 1 esp on \
		mkpart primary ext4 261MiB 30.5GiB \
		mkpart primary linux-swap 30.5GiB 40.5GiB \
		mkpart primary ext4 40.5GiB 100%; 
else	#for bios
	echo "Creating BIOS boot";					# must do "bios_grub" as flag for the set command in parted; more info: https://www.gnu.org/software/parted/manual/html_node/set.html
	parted --script "${device}" -- mklabel gpt \
		mkpart primary ext4 1MiB 261MiB \
		set 1 bios_grub on \
		mkpart primary ext4 261MiB 30.5GiB \
		mkpart primary linux-swap 30.5GiB 40.5GiB \
		mkpart primary ext4 40.5GiB 100%; 
fi

# device paths for each part created from parted
bootPath="$(ls ${device}* | grep -E "^${device}p?1$")"
rootPath="$(ls ${device}* | grep -E "^${device}p?2$")"
swapPath="$(ls ${device}* | grep -E "^${device}p?3$")"
homePath="$(ls ${device}* | grep -E "^${device}p?4$")"

wipefs "${bootPath}"
wipefs "${rootPath}"
wipefs "${swapPath}"
wipefs "${homePath}"

# format each path
if [ -d /sys/firmware/efi/efivars/ ]; then 	#if efi boot, need to change format of boot partition
	mkfs.vfat -F32 "${bootPath}"
else
	mkfs.ext4 "${bootPath}"	
fi
mkfs.ext4 "${rootPath}"		#root, swap and home in that order 
mkswap "${swapPath}"
mkfs.ext4 "${homePath}"

swapon "${swapPath}"

mount "${rootPath}" /mnt	#directory already exists ***IMPORTANT: Must mount other partitions AFTER /mnt otherwise, the other dirs will be hidden by the new /mnt filesystem
mkdir /mnt/boot; 		#IMPORTANT: DO NOT make /mnt/efi since systemd-boot by default searches and updates for configurations from /mnt/boot 
mount "${bootPath}" /mnt/boot

mkdir /mnt/home			
mount "${homePath}" /mnt/home	

pacstrap /mnt base linux linux-firmware efibootmgr dosfstools os-prober mtools linux-headers vim base-devel redshift firefox network-manager-applet bluez-utils xorg-server xorg-xinit xf86-video-intel xorg-input-libinput paccache htop tlp;

genfstab -U /mnt >> /mnt/etc/fstab

#cool side note: if you put the - after the <<, the indents will be taken into account before lines in the heredoc; it's not used here tho
arch-chroot /mnt /bin/bash <<- EOF
ln -sf /mnt/usr/share/zoneinfo/Canada/Eastern /etc/localtime 
hwclock --systohc
sed -e 's/#en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/g' -i /etc/locale.gen
locale-gen
echo "LANG=en_US.UTF-8" > /etc/locale.conf

# echo "KEYMAP=us" > /etc/vconsole.conf #changing the keyboard layout

echo "${hostname}" > /etc/hostname
cat << EOF1 > /etc/hosts
127.0.0.1	localhost
::1		localhost
127.0.1.1	${hostname}.localdomain	${hostname}
EOF1


# mkinitcpio -P #only if have encrypt fs, raid, or lvm

EOF

#***IMPORTANT: for systemd-boot, must have add initrd intel-ucode.img as FIRST initrd (assuming I have an intel CPU, otherwise put amd) 
#	must install intel-ucode pkg (or amd-ucode pkg)
#	on the contrary, GRUB automatically detects the cpu type so oh well...
if [ -d /sys/firmware/efi/efivars/ ]; then #install systemd-boot bootloader
	arch-chroot /mnt bootctl install 
	cat <<EOF > /mnt/boot/loader/loader.conf
default	arch
EOF 

pacstrap /mnt $cpu-ucode linux # must do bootctl install THEN pacstrap/install $cpu-ucode. Why? So that the img files are found in the same directory! /boot directory, and im not sure why but you have to reinstall linux so that the other .img files will appear in /boot... I will have to re organize this later...

	cat << EOF2 > /mnt/boot/loader/entries/arch.conf
title	Arch Linux
linux	/vmlinuz-linux
initrd	/$cpu-ucode.img
initrd	/initramfs-linux.img
options	root=PARTUUID=$(blkid -s PARTUUID -o value "$rootPath") rw
EOF2
else #install grub bootloader
	pacstrap /mnt grub
	arch-chroot /mnt grub-install --target=i386-pc ${device}
	#arch-chroot /mnt grub-install --target=x86_64-efi --bootloader-id=grub_uefi --efi-directory=/boot --recheck; # for uefi
	arch-chroot /mnt grub-mkconfig -o /boot/grub/grub.cfg
fi
echo "root:$password" | arch-chroot /mnt chpasswd  #chpasswd takes the format of changing passwords by (name):(new password)

elif [ $method -eq 1 ]; then
	cgdisk;
	hostname=$(dialog --stdout --inputbox "Enter hostname" 0 0) || exit 1; #if LHS unsuccess, will exit with error 1, must put semicolon to clear properly, also needs backslash for properly reading inner variables
	clear; 	# don't forget semicolon
	: ${hostname:?"hostname cannot be empty"}

	password=$(dialog --stdout --passwordbox "Enter admin password" 0 0) || exit 1; #setting root password
	clear;
	: ${password:?"password cannot be empty"}
	password2=$(dialog --stdout --passwordbox "Enter admin password again" 0 0) || exit 1;
	clear;
	[[ "$password" == "$password2" ]] || ( echo "Passwords did not match"; exit 1; )
	timedatectl set-ntp true


fi

echo "--- Finished ---"