#!/bin/bash

set -ex

add_overlayfs(){
  local root_path="$1"
  local rootfs="$root_path/rootfs" local path="$2"
  local lower="$base_rootfs/${path}"
  local upper="$root_path/.${path}-delta"
  local work="$root_path/.${path}-work"

  [[ -d "$rootfs" ]] || mkdir -p "$rootfs"
  [[ -d "$work" ]] || mkdir -p "$work"
  [[ -d "$upper" ]] || mkdir -p "$upper"

  echo "none $path overlay lowerdir=$lower,upperdir=$upper,workdir=$work 0 0" >> "$root_path/fstab"
}

options=$(getopt -o n:4:6: -l name:,ipv4:,ipv6:,path:,rootfs:,mapped-uid:,mapped-gid: -- "$@")
if [ $? -ne 0 ]; then
  usage $(basename $0)
  exit 1
fi

eval set -- "$options"
while true
do
  case "$1" in
    -n|--name)      name=$2; shift 2;;
    -4|--ipv4)      ipv4=$2; shift 2;;
    -6|--ipv6)      ipv6=$2; shift 2;;
    --path)         path=$2; shift 2;;
    --rootfs)       base_rootfs=$2; shift 2;;
    --)             shift 1; break ;;
    *)              break ;;
  esac
done

if [ -z "${name}" ]; then
  echo "missing required 'name' parameter"
  exit 1
fi

if [ -z "${path}" ]; then
  echo "missing required 'path' parameter"
  exit 1
fi

if [ -z "${base_rootfs}" ]; then
  echo "missing required 'rootfs' parameter"
  exit 1
fi

config="${path}/config"

touch "$path/fstab"
add_overlayfs "$path" "var"
add_overlayfs "$path" "etc"
add_overlayfs "$path" "home"
add_overlayfs "$path" "srv"
add_overlayfs "$path" "mnt"
add_overlayfs "$path" "root"

cat > "$config" <<EOF
lxc.include = /etc/lxc/default.conf
lxc.include = ${path}/local.conf
lxc.rootfs = ${path}/rootfs
lxc.utsname = $name
EOF
touch "$path/local.conf"

export LXC_ROOTFS_PATH="$path/rootfs"
export LXC_NAME=$name
export LXC_CONFIG_FILE="$config"
perl -n -e'/CREATE_HOOKS="([^"]+)"/ && map { system("/etc/lxc/hooks/$_") == 0 or print("executing $_ failed\n") } split(/\s+/, $1)' \
	/etc/lxc/default.conf