new_contents: #!/usr/bin/env python
  # core-ns-download
  # Check and download zip archive with zone information but only
  # if required.
  
  import requests
  import os, zipfile
  import argparse
  from io import BytesIO
  import json
  
  # Parse arguments
  parser = argparse.ArgumentParser(description='Download multible zip archives with zone information for NSD.')
  parser.add_argument('url', metavar='url', nargs='+', help='URLs with the ZIP archive')
  args = parser.parse_args()
  
  # Cache file
  cfile = '/tmp/core-ns-cache.json'
  # Nameserver directory
  nsdir = '/tmp'
  
  # Read cache information if available
  cache = {}
  try:
  	with open(cfile) as cache_file:
  		cache = json.load(cache_file)
  except:
  	pass
  
  # Get all information
  for url in args.url:
  	header = {}
  	if cache.get(url):
  		header = {
  			'If-None-Match': cache.get(url)
  		}
  	try:
  		req = requests.get(url, headers=header)
  		req.raise_for_status()
  	except Exception as e:
  		print('Problem: ' + str(e))
  		continue
  	cache[url] = req.headers.get('etag')
  	if req.ok and req.status_code == 200:
  		try:
  			z = zipfile.ZipFile(BytesIO(req.content))
  			z.extractall(nsdir)
  			subprocess.call(['nsd-control', 'reload'])
  		except Exception as e:
  			print(str(e))
  
  # Write cache information
  try:
  	with open(cfile, 'w+') as cache_file:
  		json.dump(cache, cache_file)
  except Exception as e:
  	print(str(e))
  
subject: Add our awesome core-ns download script