Automated Arch Linux installation for Lima/QEMU (aarch64)

install-arch.sh

#!/bin/bash
# Automated Arch Linux installation for Lima/QEMU
# Usage: curl -sL <gist-url>/install-arch.sh | bash
#
# Run this inside the Archboot live environment
# Installs to /dev/vda with EFI + root partitions

set -e

# Configuration
DISK="${DISK:-/dev/vda}"
HOSTNAME="${HOSTNAME:-archbox}"
TIMEZONE="${TIMEZONE:-UTC}"
LOCALE="${LOCALE:-en_US.UTF-8}"
ROOT_PASSWORD="${ROOT_PASSWORD:-arch}"

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

log() { echo -e "${GREEN}==>${NC} $1"; }
warn() { echo -e "${YELLOW}==> WARNING:${NC} $1"; }
error() { echo -e "${RED}==> ERROR:${NC} $1"; exit 1; }

# Check if running as root
[[ $EUID -ne 0 ]] && error "This script must be run as root"

# Check if disk exists
[[ ! -b "$DISK" ]] && error "Disk $DISK not found"

log "Starting Arch Linux installation to $DISK"
log "Hostname: $HOSTNAME | Timezone: $TIMEZONE"
echo ""
read -p "This will ERASE $DISK. Continue? [y/N] " -n 1 -r
echo
[[ ! $REPLY =~ ^[Yy]$ ]] && exit 1

# Step 1: Partition disk
log "Partitioning $DISK..."
parted -s "$DISK" mklabel gpt
parted -s "$DISK" mkpart ESP fat32 1MiB 513MiB
parted -s "$DISK" set 1 esp on
parted -s "$DISK" mkpart root ext4 513MiB 100%

# Wait for partitions
sleep 2
partprobe "$DISK"

# Determine partition names (handles both vda1 and vda-part1 naming)
if [[ -b "${DISK}1" ]]; then
    EFI_PART="${DISK}1"
    ROOT_PART="${DISK}2"
elif [[ -b "${DISK}p1" ]]; then
    EFI_PART="${DISK}p1"
    ROOT_PART="${DISK}p2"
else
    error "Cannot find partitions on $DISK"
fi

log "EFI partition: $EFI_PART"
log "Root partition: $ROOT_PART"

# Step 2: Format partitions
log "Formatting partitions..."
mkfs.fat -F32 "$EFI_PART"
mkfs.ext4 -F "$ROOT_PART"

# Step 3: Mount partitions
log "Mounting partitions..."
mount "$ROOT_PART" /mnt
mkdir -p /mnt/boot
mount "$EFI_PART" /mnt/boot

# Step 4: Install base system
log "Installing base system (this may take a while)..."
pacstrap -K /mnt \
    base \
    linux \
    linux-firmware \
    base-devel \
    sudo \
    openssh \
    cloud-init \
    cloud-guest-utils \
    vim \
    git \
    curl \
    wget \
    htop \
    networkmanager

# Step 5: Generate fstab
log "Generating fstab..."
genfstab -U /mnt >> /mnt/etc/fstab

# Step 6: Configure system (chroot)
log "Configuring system..."

cat > /mnt/setup.sh << CHROOT_EOF
#!/bin/bash
set -e

# Timezone
ln -sf /usr/share/zoneinfo/$TIMEZONE /etc/localtime
hwclock --systohc

# Locale
echo "$LOCALE UTF-8" > /etc/locale.gen
locale-gen
echo "LANG=$LOCALE" > /etc/locale.conf

# Hostname
echo "$HOSTNAME" > /etc/hostname
cat > /etc/hosts << EOF
127.0.0.1   localhost
::1         localhost
127.0.1.1   $HOSTNAME.localdomain $HOSTNAME
EOF

# Root password
echo "root:$ROOT_PASSWORD" | chpasswd

# Create arch user for cloud-init fallback
useradd -m -G wheel -s /bin/bash arch || true
echo "arch:arch" | chpasswd
echo "%wheel ALL=(ALL:ALL) NOPASSWD: ALL" >> /etc/sudoers

# Install bootloader (systemd-boot)
bootctl install

# Create boot entry
mkdir -p /boot/loader/entries
cat > /boot/loader/entries/arch.conf << EOF
title   Arch Linux
linux   /vmlinuz-linux
initrd  /initramfs-linux.img
options root=$ROOT_PART rw quiet
EOF

cat > /boot/loader/loader.conf << EOF
default arch.conf
timeout 3
console-mode max
EOF

# Configure cloud-init
mkdir -p /etc/cloud/cloud.cfg.d

cat > /etc/cloud/cloud.cfg.d/99_lima.cfg << EOF
# Lima/QEMU cloud-init config
datasource_list: [ NoCloud, None ]
disable_root: false
ssh_pwauth: true
users:
  - default
EOF

# Enable services
systemctl enable sshd
systemctl enable NetworkManager
systemctl enable cloud-init-local.service
systemctl enable cloud-init.service
systemctl enable cloud-config.service
systemctl enable cloud-final.service

# Generate initramfs
mkinitcpio -P

echo "Setup complete inside chroot"
CHROOT_EOF

chmod +x /mnt/setup.sh
arch-chroot /mnt /setup.sh
rm /mnt/setup.sh

# Step 7: Unmount and finish
log "Unmounting..."
umount -R /mnt

echo ""
echo -e "${GREEN}========================================${NC}"
echo -e "${GREEN}  Arch Linux installation complete!${NC}"
echo -e "${GREEN}========================================${NC}"
echo ""
echo "Default credentials:"
echo "  root:$ROOT_PASSWORD"
echo "  arch:arch (sudo enabled)"
echo ""
echo "Run 'poweroff' to shutdown and save the image."
echo "Then update your Lima config to use the new qcow2."