#!/bin/bash
# Copyright (C) 2019 Ian Kelling
# SPDX-License-Identifier: Apache-2.0

if ! test "$BASH_VERSION"; then echo "error: shell is not bash" >&2; exit 1; fi
shopt -s inherit_errexit 2>/dev/null ||: # ignore fail in bash < 4.4
set -eE -o pipefail
trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" exit status: $?, PIPESTATUS: ${PIPESTATUS[*]}" >&2' ERR
# alternatively, using https://iankelling.org/git/?p=errhandle;a=tree
# source /path/errhandle/err
# on my machine
source /a/bin/errhandle/err

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

subvol=$1 # eg ubuntubionic
nr=$2 # new root

if (( $# != 2 )); then
  echo $0: error expected 2 arguments
  exit 1
fi

# lots of this is taken from default.PARTITION

if (($(nproc) > 2)); then
  mopts=,compress=zstd
fi

rm -f $nr/etc/{fs,crypt}tab
while read -r line; do
  printf "%s none  keyscript=decrypt_keyctl,discard,luks,initramfs\n" "$line" >>$nr/etc/crypttab
done < <(awk '{print $1,$2}' /mnt/root/root2-crypttab)
awk '$3 == "/dev/urandom" {print}' /etc/crypttab >>$nr/etc/crypttab


rootdev=$(awk '$2 == "/mnt/root2" {print $1}' /mnt/root/root2-fstab)
fstabstd=x-systemd.device-timeout=30s,x-systemd.mount-timeout=30s
bootdev=$(awk '$2 == "/mnt/boot2" {print $1}' /mnt/root/root2-fstab)


cat >> $nr/etc/fstab <<EOF
$rootdev  /  btrfs $fstabstd,noatime,subvol=root_$subvol$mopts  0 0
$rootdev  /mnt/root  btrfs  $fstabstd,noatime,subvolid=0$mopts  0 0
$bootdev  /boot btrfs  nofail,$fstabstd,noatime,subvol=boot_$subvol  0 0
$bootdev  /mnt/boot  btrfs  nofail,$fstabstd,noatime,subvolid=0  0 0
tmpfs     /tmp tmpfs     nodev,nosuid,size=50%,mode=1777   0    0
EOF
awk '$2 == "/boot/efi" {print}' /etc/fstab >>$nr/etc/fstab


while read -r mdname; do
  cat >> $nr/etc/fstab <<EOF
/dev/mapper/$mdname  none  swap  nofail,$fstabstd,sw  0 0
EOF
done < <(awk '$3 == "/dev/urandom" {print $1}' /etc/crypttab)