#!/usr/bin/env ruby
require 'json'
require 'fileutils'

abort "Must run as root" unless Process.uid == 0

CONTAINER_DATA = "/etc/lxc/container.json"

data = JSON.load(File.open(CONTAINER_DATA))
containers = `lxc-ls -1`.split(/\n/)

modified = false
data["network"].each do |host, value|
  unless containers.include?(host) or value["lxc"] == false
    data["network"].delete(host)
    modified = true
  end
end

if modified
  FileUtils.cp(CONTAINER_DATA, CONTAINER_DATA + ".backup")
  File.open(CONTAINER_DATA, "w+") do |f|
    f.puts JSON.pretty_generate(data)
  end
else
  puts "Unchanged"
end