Simple command for automatic update of current ip of ec2 instance in route53.

rt53.py

# -*- coding: utf-8 -*-

from __future__ import print_function

import argparse
import socket
import fcntl
import struct
import os
import sys

from boto.route53.connection import Route53Connection, ResourceRecordSets


def get_ip_address(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    return socket.inet_ntoa(fcntl.ioctl(
        s.fileno(),
        0x8915,  # SIOCGIFADDR
        struct.pack('256s', ifname[:15])
    )[20:24])


class Route53(object):
    def __init__(self, key, secret, ifname):
        self.connection = Route53Connection(key, secret)
        self.ifname = ifname
    
    def get_new_value(self):
        return get_ip_address(self.ifname)

    def zone_name_to_id(self, zone_name):
        zone = self.connection.get_hosted_zone_by_name(zone_name)
        zone_id = zone.HostedZone.Id.rsplit("/", 1)[1]
        return zone_id

    def update_or_create(self, zone_name, domain, ttl=120):
        zone_id = self.zone_name_to_id(zone_name)
        changes = ResourceRecordSets(self.connection, zone_id, "")

        if not domain.endswith("."):
            domain = domain + "."

        for record in self.connection.get_all_rrsets(zone_id, "A", zone_name):
            if record.name == domain:
                change_delete = changes.add_change("DELETE", record.name, record.type, record.ttl,
                                                identifier=record.identifier, weight=record.weight)

                for item in record.resource_records:
                    change_delete.add_value(item)

                break

        value = self.get_new_value()
        change_create = changes.add_change("CREATE", domain, "A", ttl)
        change_create.add_value(value)
        
        print("IP ADDR:", value)
        return changes.commit()


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='SimpleUpdate route53')
    parser.add_argument('-z', '--zone', dest="zone", required=True,
                            help=u"Zone name change or create")

    parser.add_argument('-d', '--domain', dest="domain", required=True,
                            help=u"Domain name change or create")

    parser.add_argument('--access-key', dest="aws_key",
                            help=u"AWS api key.")

    parser.add_argument('--secret-key', dest="aws_secret",
                            help=u"AWS secret key.")

    parser.add_argument('--ifname', dest="ifname", default="eth0",
                            help=u"Interface name.")

    parser.add_argument('--ttl', type=int, dest="ttl", default=120)
    args = parser.parse_args()

    route53 = Route53(args.aws_key, args.aws_secret, args.ifname)
    result = route53.update_or_create(args.zone, args.domain, args.ttl)

    print(result)