#!/bin/bash
# Copyright (C) 2018 Ian Kelling

# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

x="$(readlink -f "$BASH_SOURCE")"; source "${x%/*}/bash-trace"

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

LC_USEBASHRC=t; . ~/.bashrc

usage() {
  cat <<EOF
usage: ${0##*/} [-h|--help] [BASE_CODENAME] [ARCH]
install fai-server on the current machine

Initial setup of a fai server. works on localhost.  Set's the current ip
as the tftp server. I vaguely remember that using a hostname does not
work.  Separate from running this, faiserver needs to be setup in dns to
point to whatever host this is run on.

Default BASE_CODENAME is bullseye. Default ARCH is 64. The script expects corresponding
$BASEFILE_DIR/${UPCASED_BASE_CODENAME}${ARCH}.tar.(gz|xz) to exist, and it must have been
generated around the same time as the nfsroot, at least so it has the
same kernel version.


Note: there is a bug in 5.9.4, fixed by adding
    sleep 2

Note: in t9, there is a bug in recent fai packages (eg 2021+), where
  unshare uses a too new argument. I was able to fix it by
  just going to the site of the error and changing unshare to
  chroot like it used to be, but I'm not bothering to make
  any persistent fix, since I'm now on t10. If it ever came
  up again, using an old fai package would also work.

/usr/sbin/fai-make-nfsroot:503, before apt-get update


EOF
  exit $1
}
case $1 in
  -h|--help) usage ;;
esac


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


base=${1:-bullseye}
arch=${2:-64}

if [[ $base == [[:upper:]] ]]; then
  echo $0: error: use lowercase base
  exit 1
fi

basefile=($BASEFILE_DIR/${base^^}${arch^^}.tar.gz)
sed="sed -ri --follow-symlinks"

if [[ ! -e $basefile ]]; then
  printf "%s\n" "$0: error basefile=$basefile  does not exist" >&2
  exit 1
fi

if [[ ! -d $BASEFILE_DIR ]]; then
  printf "%s\n" "$0: error BASEFILE_DIR=$BASEFILE_DIR  does not exist" >&2
  exit 1
fi


if ! type -p wget &>/dev/null; then
  apt-get install -y wget
fi

armhf() {
  [[ $(dpkg --print-architecture) == armhf ]]
}

# fai on ubuntu only has official support using the universe repo, but newer
# tends to have less bugs.
wget -O - https://fai-project.org/download/2BF8D9FE074BCDE4.asc | apt-key add -

update=false
case $base in
  stretch|bullseye|bullseye)
    if ! grep -qFx "deb https://fai-project.org/download $base koeln" /etc/apt/sources.list.d/fai.list; then
      update=true
    fi
    cat >/etc/apt/sources.list.d/fai.list <<EOF
deb https://fai-project.org/download $base koeln
EOF
    ;;
  *)
    echo "$0: error: script needs updating for new base" >&2
    exit 1
    ;;
esac

f=/var/cache/apt/pkgcache.bin;
if [[ -r $f ]]; then
  cachetime=$(stat -c %Y $f );
  now=$(date +%s)
  limittime=$(( now - 60*60*2 ))
  if (( cachtime > limittime )); then
    update=true
  fi
fi

if $update; then
  apt-get update
fi

# Relevant packages from fai-quickstart depends and fai-server recommends.
# I especially do not wait isc-dhcp-server or an inetd. Also excludes
# nfs-kernel-server. On an android chroot, we don\'t have nfs in the
# kernel, or the ability to install it.
# xorriso is for running fai-cd -a, not strictly need for fai-server
# perl-tk is for fai-monitor-gui
# mtools is for fai-cd
pkgs=(fai-doc tftpd-hpa tar reprepro squashfs-tools binutils xorriso perl-tk mtools)
if modprobe nfsd &>/dev/null; then
  pkgs+=(nfs-kernel-server)
else
  pkgs+=(apache2)
fi


e apt-get install -y ${pkgs[@]}
# confnew since we edit /etc/fai/NFSROOT in an automated way
# fai-client is already a fai-server dependency, but make sure it gets upgraded
e apt-get install --no-install-recommends -y -o Dpkg::Options::=--no-force-confdef -o Dpkg::Options::=--force-confnew fai-server fai-client

r=http://http.us.debian.org/debian
# like default, but scrap httpredir, and nonfree.
# All my systems should be able to get along without nonfree
# for a base working system afaik.

cat >/etc/fai/apt/sources.list <<EOF
deb $r $base main contrib
EOF

### begin setup security repo ###
case $base in
  stretch|buster)
    cat >>/etc/fai/apt/sources.list <<EOF
deb http://security.debian.org/debian-security $base/updates main contrib
EOF
    ;;
  *)
    # new naming convention
    cat >>/etc/fai/apt/sources.list <<EOF
deb http://security.debian.org/debian-security $base-security main contrib
EOF
esac
### end setup security repo ###


cat >>/etc/fai/apt/sources.list <<EOF
# use fai repo. it's commented in the defaults. it's got bug fixes.
# and may contain newer packages.
deb http://fai-project.org/download $base koeln
EOF

## Get latest kernel and btrfs for dealing with btrfs issues.
# if [[ $base == buster ]]; then
#   cat >>/etc/fai/apt/sources.list <<'EOF'
# deb http://ftp.debian.org/debian buster-backports main
# EOF
#   # note, fai doesn\'t look at /etc/fai/apt/preferences.d
#   cat >/etc/fai/apt/preferences <<'EOF'
# Package: linux-* firmware-linux-free btrfs-progs
# Pin: release a=buster-backports
# Pin-Priority: 500
# EOF
# fi


$sed -f - /etc/fai/nfsroot.conf <<EOF
$ a FAI_ROOTPW='$(</q/root/shadow/standard)'
/^\s*FAI_ROOTPW/d
$ a SSH_IDENTITY=/root/.ssh/home.pub
/^\s*SSH_IDENTITY/d
s,^( *FAI_DEBOOTSTRAP=).*,\1"$base $r",
# add --arch amd64. this is needed on arm system which is
# used to install amd64 clients. On amd64 servers, it's redundant.
# disabled for now, since creating fai nfsroot on my arm machine
# is not working
#/--arch amd64/!s/^(\s*FAI_DEBOOTSTRAP_OPTS=")/\1--arch amd64 /
EOF

$sed 's/#LOGUSER/LOGUSER/' /etc/fai/fai.conf
$sed -i '/^LOGUSER=/d' /etc/fai/fai.conf
$sed -i '/^FAI_FLAGS=/d' /etc/fai/fai.conf
echo "FAI_FLAGS=verbose" >>/etc/fai/fai.conf
# note if this isnt set, the user isnt created
echo "LOGUSER=fai" >>/etc/fai/fai.conf

# from man fai-make-nfsroot,
# figured out after partitioning ignored my crypt partition


cedit /etc/fai/NFSROOT <<'EOF' || [[ $? == 1 ]]
# inserted by faserver-setup
PACKAGES install
cryptsetup
# default one is linux-image-server, doesnt exist anymore
linux-image-amd64
# default is btrfs-tools which doesnt exist anymore
btrfs-progs
iw
# got an error in error.log about not having gpg.
# system seemed to still install ok, so i havent tested if this fixes it.
gpg
EOF

if armhf; then
  cd /srv/fai
  e rm -rf nfsroot
  e tar Jxf $basefile
  # background: Can't build the nfsroot on my arm system now.  First,
  # fai-make-nfsroot won't work out of the box. One idea to make it work
  # is by installing qemu-user-static, then copying qemu-x86_64-static
  # into the nfsroot, and prepending it to chroot commands in
  # fai-make-nfsroot, but that fails in odd ways. ls has permissions
  # problems on reading directories, various programs segfault
  # immediately, cat can't open a file, etc.

  NFSROOT=/srv/fai/nfsroot
  TFTPROOT=/srv/tftp/fai

  # test if our copy of setup_tftp has changed in fai-make-nfsroot,
  # and if not, run it.
  setup_tftp(){

    # tftp environment
    local pxebin

    # jessie+ path
    pxebin=$NFSROOT/usr/lib/syslinux/pxelinux.0

    rm -f $NFSROOT/boot/*.bak
    mkdir -p $TFTPROOT/pxelinux.cfg
    if ! chmod a+r $NFSROOT/boot/initrd.img-*; then
      echo "$0: error: No initrd was created. Check the package name of the linux-image package in /etc/fai/NFSROOT."
      exit 1
    fi
    cp -p $v $NFSROOT/boot/vmlinu?-* $NFSROOT/boot/initrd.img-* $TFTPROOT
    cp -u $pxebin $TFTPROOT
    if [ -f $NFSROOT/usr/lib/syslinux/modules/bios/ldlinux.c32 ]; then
      cp -u $NFSROOT/usr/lib/syslinux/modules/bios/ldlinux.c32 $TFTPROOT
    fi
    if [ X$verbose = X1 ]; then
      echo "TFTP environment prepared. Enable DHCP and start the TFTP daemon on root $TFTPROOT."
    fi
  }
  diff -u <(type setup_tftp) <(cat <(sed -n '/^setup_tftp(){/,/^}/p' $(which fai-make-nfsroot) ) - <<'EOF' |bash
type setup_tftp
EOF
                              )
  e setup_tftp

  # -g causes skipping set_root_pw() in fai-make-nfsroot, -ag
  # is the only way to make it run without chrooting. the options
  # seem contradictory, but it works.
  e fai-setup -evag

else # not armhf
  # note, this copies the -B arg to
  # /srv/fai/nfsroot/var/tmp/base.tar.xz
  e fai-setup -evf -B $basefile
  # fai-setup expert mode avoids writing to /var/log/fai/variables
  # at least config_src is needed for autodiscover
  $sed '/^FAI_CONFIGDIR|^FAI_CONFIG_SRC|^LOGUSER/d' /var/log/fai/variables
  tee -a /var/log/fai/variables <<'EOF'
LOGUSER=fai
FAI_CONFIGDIR=/srv/fai/config
FAI_CONFIG_SRC=nfs://faiserver/srv/fai/config
EOF
  # make the faiserver also the apt proxy server
  apt-get -y install apt-cacher-ng
fi

rm -f /srv/fai/nfsroot/root/.ssh/known_hosts
if [[ $HOSTNAME == kd ]]; then
  keyscan_arg="-p 8989"
  fi
key=$(ssh-keyscan $keyscan_arg localhost |& grep -o "ecdsa-sha2-nistp256.*")
for ip in faiserver $(ip addr show up| grep -w '^ *inet' | awk '{print $2}'| cut -d / -f 1 | grep -vF 127.0.0.1); do
  echo "$ip $key" >>/srv/fai/nfsroot/root/.ssh/known_hosts
done

# make it the root because pxe-kexec only looks there.
# It wouldn't be too hard to change if we needed.
# We could also just dump things in /srv/tftp, but fai
# has some defaults, which I don't even use, which expect
# the other directory, so it's kind of a tossup, whatever.
sed -ri 's,^ *(TFTP_DIRECTORY=).*,\1"/srv/tftp/fai",' /etc/default/tftpd-hpa
systemctl restart tftpd-hpa


# serial console
# mainly from
# https://wiki.archlinux.org/index.php/working_with_the_serial_console
# at runtime, running this from ssh worked:
# https://unix.stackexchange.com/questions/242778/what-is-the-easiest-way-to-configure-serial-port-on-linux
# stty -F /dev/ttyS0 115200 cs8 -cstopb -parenb
# /sbin/agetty 115200 ttyS0 linux
# dated info, but validation that this might work on debian:
# https://help.ubuntu.com/community/SerialConsoleHowto
# note in the nfsroot, systemd is not running.
echo "c0:2345:respawn:/sbin/agetty 115200 ttyS0 linux" >>/srv/fai/nfsroot/etc/inittab

# initially did the basic fai-chboot -Iv $std_arg default
# but found in console that it wanted to mount nfsroot
# to be the same as my dhcp server.
# Figured out to change the root= parameter from googling,
# and seeing fai-chboot -L
# using hostname failed.
# for -f, combined the 2 defaults so it will reboot and print to screen.

# Add debug to -f flag for more verbose output.


# background on choosing apt-cacher-ng:
# googling around a bit finds 2 main solutions:
# http://askubuntu.com/questions/3503/best-way-to-cache-apt-downloads-on-a-lan
# apt-cacher-ng doesn\'t have zeroconf.
# It touts having minimal dependencies, but I don\'t care.
# The downside to squid-deb-proxy is that it\'s config is for specific repos,
# you have to add all the repos you use.
# That is the main reason I use apt-cacher-ng.
# It has a web portal, at http://faiserver:3142/acng-report.html


# random fai note: as far as I can tell, profiles are just for putting
# in a selectable boot menu, which I don\'t want.

# the logsave prompted because the hostname faiserver was uknown.
# Here it was faiserver.lan when running from a faiserver vm.
# When running from a normal host with faiserver alias, it was the normal hosts name.
$sed 's/(^[^,]+,)\S+/\1faiserver/' /srv/fai/nfsroot/root/.ssh/known_hosts
# ditch the logo banner up top which screws with less.
touch /srv/fai/nfsroot/.nocolorlogo