#!/bin/bash

set -eE -o pipefail
trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR

case $1 in
    -h|--help)
        echo "see help from myfai-chboot"
        exit 0
        ;;
esac

[[ $EUID == 0 ]] || exec sudo "${BASH_SOURCE}" "$@"

e() { echo "$@"; "$@"; }


rm -f /srv/tftp/fai/pxelinux.cfg/*
if [[ ! $1 ]]; then
    exit 0
fi

host=$1
ip=$(getent hosts $host | awk '{print $1}')

std_arg="-u nfs://faiserver/srv/fai/config"
e fai-chboot -Iv $std_arg default # set it to default to get a val out of it next
kernel=$(fai-chboot -L '^default$' | awk '{print $3}')
# man page doesn't explain this, but this deletes & thus disables
# all chboot systems.
type -t host &>/dev/null || apt-get -y install dnsutils
gateway_ip=$(route -n | sed -rn 's/^0\.0\.0\.0\s+(\S+).*/\1/p')
my_ip=$(host faiserver $gateway_ip | sed -rn 's/^\S+ has address //p')
k_args=$(fai-chboot -L '^default$' | \
             sed -r "s/^(\S+\s+){3}(.*root=)(.*)/\2$my_ip:\3/")
rm -f /srv/tftp/fai/pxelinux.cfg/*
e fai-chboot -k "$k_args" -v -f verbose,sshd,createvt,reboot $std_arg $kernel "$host"

# fai-setup without -e sets the ip to the local_ip/local_network, eg 192.168.1.3/24
# I restrict it to one ip as simple but imperfect access control.
sed -ri --follow-symlinks '\%^/srv/fai/%d' /etc/exports
cat >>/etc/exports <<EOF
/srv/fai/config $ip/32(async,ro,no_subtree_check)
/srv/fai/nfsroot $ip/32(async,ro,no_subtree_check,no_root_squash)
EOF
exportfs -ra


# todo, remove the nopxe script. adjust fai-check to reboot if it fails on the kexec.