#!/bin/sh

# Purpose : {{{
# Proxmox only reads /etc/network/interfaces from a while
#		See : https://forum.proxmox.com/threads/anyway-to-support-interfaces-d.34739/
# So any bridge,… in the subdirectory /etc/network/interfaces.d won't be
# available from webgui to manage KVM/LXC's network device.
# }}}
# This script will try to fix this waiting for a Proxmox's fix. {{{
#		Check if /etc/network/interfaces.d contains file(s)
#		Create a temp interfaces file
#		Add some basic/header informations to the temp file
#		Cat the content of interfaces.d files to the temp file
#		Replace default interfaces file with the temp one

# }}}

interfaces_dir="/etc/network/interfaces.d"
interfaces_temp="/etc/network/interfaces.temp.script"

# Test if interfaces.d is empty
if [ -z "$(ls -A ${interfaces_dir})" ]; then
	exit 0
fi

# Create temp file
rm -f -- "${interfaces_temp}"
touch -- "${interfaces_temp}"

# Header informations
printf '%b' "# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
" >> "${interfaces_temp}"

# Loopback informations if not present in interfaces.d
grep -q -R "iface lo" "${interfaces_dir}" || printf '%b' "
# The loopback network interface
auto lo
iface lo inet loopback
" >> "${interfaces_temp}"

# Cat the content of interfaces.d to temp file (POSIX way)
find "${interfaces_dir}" -type f -exec cat {} >> "${interfaces_temp}" \;

# Define it a new interfaces file
mv -- "${interfaces_temp}" /etc/network/interfaces

exit 0