#!/usr/bin/env bash
# Usage: tools/build-rootfs [-h]
#
# Builds the werkrevisor image and exports its file system
# as werkrevisor-rootfs-<version>.tar.zst for hosts without Docker (werkdock).
# Run it from the repository root.
# The archive does not keep image metadata; run it with
#   PATH=/app/.venv/bin:/usr/local/bin:/usr/bin:/bin PYTHONPATH=/werkrevisor:/app PYTHONNOUSERSITE=1 python -s -m werkrevisor
set -euo pipefail

if [[ "${1:-}" =~ ^(-h|-\?|--help)$ ]]; then
    awk 'NR > 1 && /^#/ { sub(/^# ?/, ""); print; next } NR > 1 { exit }' "$0"
    exit 0
fi

version=$(sed -n 's/^__version__ = "\(.*\)"$/\1/p' werkrevisor/__init__.py)
image="werkrevisor:${version}"
archive="werkrevisor-rootfs-${version}.tar.zst"

docker build --pull=false -t "$image" .
container=$(docker create "$image")
trap 'docker rm -f "$container" >/dev/null' EXIT
docker export "$container" | zstd -q -T0 -10 -f -o "$archive"
echo "image:   $image"
echo "archive: $archive ($(du -h "$archive" | cut -f1))"
sha256sum "$archive"