A shell script to create chroot jail

mkjail.sh

#!/bin/sh

set -e

arch=`uname -m`
release=`uname -r`

show_help() {
cat << EOF
Usage: ${0##*/} [-h] [-m ARCH] [-r RELEASE] [-i IMAGE] [-d DIR] PATH

Create a chroot jail at PATH with the file sets downloaded from
/etc/installurl.

    -h          display this help and exit.

    -m ARCH     choose the machine hardware name (defaults to
                $arch).

    -r RELEASE  choose the OS release (defaults to $release).

    -i IMAGE    create jail from an ISO 9660 image containing
                file sets.

    -d DIR      create jail from a directory containing file
                sets.

EOF
}

OPTIND=1
while getopts "hm:r:i:d:" opt; do
    case $opt in
        h)
            show_help
            exit 0
            ;;
        m)
            arch=$OPTARG
            ;;
        r)
            release=$OPTARG
            ;;
        i)
            image=$OPTARG
            (! [ -f "$image" ]) && (show_help >&2) && exit 1
            ;;
        d)
            file_dir=$OPTARG
            (! [ -d "$file_dir" ]) && (show_help >&2) && exit 1
            ;;
        '?')
            show_help >&2
            exit 1
            ;;
        :)
            show_help >&2
            exit 1
            ;;
    esac
done

shift $((OPTIND-1))

short_release=`echo $release | sed "s/\.//g"`

[ -z "$1" ] && (show_help >&2) && exit 1

cleanup_iso() {
    umount "$1"
    vnconfig -u "$2"
    rm -rf "$1"
}

mount_iso() {
    vnd_dev="$(/sbin/vnconfig -l | awk -F ':' '/not in use/ { print $1 ; exit }')"
    [ -z "$vnd_dev" ] && (echo "No vnd device available" >&2) && exit 1
    vnconfig "$vnd_dev" "$1"
    echo "Mount $1 onto $2"
    mount -t cd9660 "/dev/${vnd_dev}c" "$2"
    trap "cleanup_iso $2 $vnd_dev" EXIT
}

download() {
    cd "$1"
    installurl=`cat /etc/installurl`
    home="${installurl}/${release}/${arch}"
    ftp "${home}/SHA256.sig"
    for fileset in base comp game man xbase xfont xserv xshare
    do
        filename="${fileset}${short_release}.tgz"
        ftp "${home}/${filename}"
        signify -Cp "/etc/signify/openbsd-${short_release}-base.pub" -x SHA256.sig "$filename"
    done
    cd - 2>&1 >/dev/null
}

if [ -f "$image" ]; then
    dir=`mktemp -p /tmp -d jail.XXXXXXXXXX` || exit 1
    mount_iso "$image" "$dir"
    files="${dir}/${release}/${arch}/*${short_release}.tgz"
elif [ -d "$file_dir" ]; then
    echo "Use file sets in ${file_dir} directly"
    files="${file_dir}/*${short_release}.tgz"
else
    file_dir=`mktemp -p /tmp -d jail.XXXXXXXXXX` || exit 1
    trap "rm -rf $file_dir" EXIT
    echo "Download file sets to ${file_dir}"
    download "$file_dir"
    files="${file_dir}/*${short_release}.tgz"
fi

jail=$1

mkdir $jail

for file in $files
do
    echo "Extract ${file} to ${jail}"
    tar -C $jail -zxphf $file
done