#!/bin/bash

configure_modprobe() {
  local sysext_name="${1}"
  shift

  local module_directories=(./usr/lib/modules/*-flatcar/)

  mkdir -p ./usr/lib/modprobe.d/
  for module_name in $(find "${module_directories[@]}" -type f \( -name "*.ko" -o -name "*.ko.*" \) -printf "%f\n" | sed -E 's/\.ko(\.\w+)?$//'); do
    cat <<EOF >> "./usr/lib/modprobe.d/10-${sysext_name}-kmod-sysext.conf"
install $module_name /usr/libexec/_${sysext_name}_modprobe_helper $module_name
remove $module_name /usr/libexec/_${sysext_name}_modprobe_helper -r $module_name
EOF
  done

  mkdir -p ./usr/libexec/
  install -m0755 -D /dev/stdin "./usr/libexec/_${sysext_name}_modprobe_helper" <<'EOF'
#!/bin/bash

set -euo pipefail

action="Loading"
for arg in "$@"; do
    if [[ $arg == "-r" ]]; then
        action="Unloading"
    fi
done
echo "$action kernel module from a sysext..."

KMOD_PATH=/usr/lib/modules/$(uname -r)
TMP_DIR=$(mktemp -d)
trap "rm -rf -- '${TMP_DIR}'" EXIT
mkdir "${TMP_DIR}"/{upper,work}

unshare -m bash -s -- "${@}" <<FOE
set -euo pipefail
if ! mountpoint -q "${KMOD_PATH}"; then
    mount -t overlay overlay -o lowerdir="${KMOD_PATH}",upperdir="${TMP_DIR}"/upper,workdir="${TMP_DIR}"/work "${KMOD_PATH}"
    depmod
fi
modprobe --ignore-install "\${@}"
FOE
EOF

  # prevent the sysext from masking /usr/lib/modules/*-flatcar/modules.XXX
  find "${module_directories[@]}" -maxdepth 1 -mindepth 1 -type f -delete
}