future-install-scripts/arch-chroot.in

#!/bin/bash

shopt -s extglob

# m4_include() is recognized as a function definition
# shellcheck source=common disable=SC1073,SC1065,SC1064,SC1072
m4_include(common)

setup=chroot_setup
unshare=0
userspec=''
chroot_args=()

usage() {
  cat <<EOF
usage: ${0##*/} [options] chroot_dir [command [arguments...]]

  Options:
    -N                  Run in unshare mode as a regular user
    -u <user>[:group]   Specify non-root user and group (optional) to use

    -h                  Print this help message

If 'command' is unspecified, arch-chroot will launch /bin/bash.

Note that when using arch-chroot, the target chroot directory *should* be a
mountpoint. This ensures that tools such as pacman(8) or findmnt(8) have an
accurate hierarchy of the mounted filesystems within the chroot.
If your chroot target is not a mountpoint, you can bind mount the directory on
itself to make it one, i.e. 'mount --bind chroot_dir chroot_dir'.

EOF
}

if [[ -z $1 || $1 = @(-h|--help) ]]; then
  usage
  exit $(( $# ? 0 : 1 ))
fi

while getopts ':Nu:' flag; do
  case $flag in
    N)
      setup=unshare_setup
      unshare=1
      ;;
    u)
      userspec="$OPTARG"
      ;;
    :)
      die "%s: option requires an argument -- '%s'" "${0##*/}" "$OPTARG"
      ;;
    ?)
      die "%s: invalid option -- '%s'" "${0##*/}" "$OPTARG"
      ;;
  esac
done
shift $(( OPTIND - 1 ))

(( $# )) || die 'No chroot directory specified'
chrootdir="$1"; shift

if ! mountpoint -q "$chrootdir"; then
  warning '%s is not a mountpoint, and thus may cause undesirable side effects. (See help for more info)' "$chrootdir"
fi

command=("$@")

arch-chroot() {
  check_root

  [[ -d "$chrootdir" ]] || die '%s: not a directory' "$chrootdir"

  $setup "$chrootdir"
  chroot_add_resolv_conf "$chrootdir" || die 'Failed to setup resolv.conf in chroot'

  [[ $userspec ]] && chroot_args+=(--userspec="$userspec")

  SHELL=/bin/bash $pid_unshare chroot "${chroot_args[@]}" -- "$chrootdir" "${command[@]}"
}

if (( unshare )); then
  $mount_unshare bash -c "$(declare_all); arch-chroot"
else
  arch-chroot
fi

# vim: et ts=2 sw=2 ft=sh: