haos.sh

#!/usr/bin/env bash
set -euo pipefail

# Writes Home Assistant OS to this machine's internal disk.
# Intended to be run from a live Ubuntu USB session, not from the OS installed
# on the internal drive.

DEFAULT_IMAGE="$HOME/Downloads/haos_generic-x86-64-17.3.img.xz"
DEFAULT_TARGET="/dev/nvme0n1"

IMAGE="${1:-$DEFAULT_IMAGE}"
TARGET="${2:-$DEFAULT_TARGET}"

die() {
  echo "ERROR: $*" >&2
  exit 1
}

need_cmd() {
  command -v "$1" >/dev/null 2>&1 || die "Missing required command: $1"
}

parent_disk() {
  local dev="$1"
  local pk

  pk="$(lsblk -no PKNAME "$dev" 2>/dev/null | head -n1 || true)"
  if [[ -n "$pk" ]]; then
    printf '/dev/%s\n' "$pk"
    return
  fi

  # If this is already a whole disk, lsblk PKNAME is empty.
  if [[ -b "$dev" ]]; then
    printf '%s\n' "$dev"
  fi
}

need_cmd lsblk
need_cmd findmnt
need_cmd xzcat
need_cmd dd
need_cmd sync

[[ -f "$IMAGE" ]] || die "HAOS image not found: $IMAGE"
[[ "$IMAGE" == *.img.xz ]] || die "Expected a compressed .img.xz HAOS image: $IMAGE"
[[ -b "$TARGET" ]] || die "Target block device not found: $TARGET"

target_type="$(lsblk -dnro TYPE "$TARGET")"
[[ "$target_type" == "disk" ]] || die "Target must be a whole disk, not a partition: $TARGET"

root_source="$(findmnt -nro SOURCE / || true)"
root_disk=""
if [[ -n "$root_source" && "$root_source" == /dev/* ]]; then
  root_disk="$(parent_disk "$root_source")"
fi

if [[ -n "$root_disk" && "$root_disk" == "$TARGET" ]]; then
  die "$TARGET appears to contain the currently running root filesystem. Boot from the Ubuntu live USB and run this script there."
fi

echo
echo "Home Assistant OS disk writer"
echo
echo "Image:  $IMAGE"
echo "Target: $TARGET"
echo
echo "Current disk layout:"
lsblk -o NAME,SIZE,TYPE,FSTYPE,LABEL,MOUNTPOINTS,MODEL,TRAN
echo
echo "This will ERASE ALL DATA on $TARGET and replace it with Home Assistant OS."
echo "The internal Pop!_OS install and all files on that disk will be destroyed."
echo
read -r -p "Type WRITE HAOS to continue: " confirm
[[ "$confirm" == "WRITE HAOS" ]] || die "Confirmation did not match; aborting."

echo
echo "Unmounting any mounted partitions on $TARGET..."
while read -r mountpoint; do
  [[ -n "$mountpoint" ]] || continue
  sudo umount "$mountpoint"
done < <(lsblk -nrpo MOUNTPOINTS "$TARGET" | sed '/^$/d')

echo
echo "Writing HAOS image to $TARGET..."
echo "Do not power off or unplug anything until this finishes."
xzcat "$IMAGE" | sudo dd of="$TARGET" bs=4M status=progress conv=fsync

echo
echo "Flushing remaining writes..."
sync

echo
echo "Final disk layout:"
lsblk -o NAME,SIZE,TYPE,FSTYPE,LABEL,MOUNTPOINTS,MODEL,TRAN "$TARGET" || lsblk -o NAME,SIZE,TYPE,FSTYPE,LABEL,MOUNTPOINTS,MODEL,TRAN

echo
echo "Done. Shut down, remove the Ubuntu USB, and boot from the internal drive."
echo "Home Assistant should become available at: http://homeassistant.local:8123"