Roll your own dynamic DNS with Route53

autodns.py

#!/usr/bin/python

"""
Uses reflect.php on sakaki to figure out external IP and then requests Amazon updates the record for home.jamesoff.net with that

JMS
20131019
"""

HOSTED_ZONE_ID = "Z1BQWQ5LVT6ZAX"
DNS_NAME = "home.jamesoff.net"

import sys

import requests
import boto
import socket

try:
   r = requests.get("http://sakaki.jamesoff.net/~james/reflect.php")
except Exception, e:
   print "Error loading data from reflect service"
   print e
   sys.exit(1)

if r.status_code != 200:
   print "Did not get status code 200 from remote service"
   sys.exit(1)

try:
    if r.json()["error"]:
       print "Got error from remote service"
       sys.exit(1)
except:
    print "Got response 200 but had error parsing JSON"

try:
   current_dns = socket.gethostbyname(DNS_NAME)
   if current_dns == r.json()["your_ip"]:
      #print "Current entry matches (%s)" % current_dns
      sys.exit(0)
except socket.gaierror, e:
   if e.errno == 8:
      print "No record currently exists for %s" % DNS_NAME
except Exception, e:
   print "Error lookup up current IP"
   print e
   sys.exit(1)

try:
   route53 = boto.connect_route53()
   records = route53.get_all_rrsets(HOSTED_ZONE_ID)
   change1 = records.add_change("DELETE", DNS_NAME, "A")
   change1.add_value(current_dns)
   change2 = records.add_change("CREATE", DNS_NAME, "A")
   change2.add_value(r.json()["your_ip"])
   records.commit()
except Exception, e:
   print "Error changing record at Amazon"
   print e
   sys.exit(2)