dotfiles/bin/dyndns

#!/usr/bin/env python
# http://blog.vrypan.net/2012/12/20/dynamic-dns-with-route53/
import os
import subprocess
import sys

from area53 import route53
from boto.route53.exception import DNSServerError


def get_ip():
    p = subprocess.Popen(['/usr/bin/dig',
                          '+short',
                          '@resolver1.opendns.com',
                          'myip.opendns.com'], stdout=subprocess.PIPE)

    output, err = p.communicate()

    if not err:
        return output.strip()
    else:
        sys.exit(1)


def setup_env():
    access_key = subprocess.check_output(['/home/tyler/bin/getnetrc',
                                          'duplicity', 'login'])
    key_id = subprocess.check_output(['/home/tyler/bin/getnetrc', 'duplicity'])
    os.environ['AWS_ACCESS_KEY_ID'] = key_id.strip()
    os.environ['AWS__SECRET_ACCESS_KEY'] = access_key.strip()


def main():
    setup_env()
    sub_domain = 'home'
    domain = 'tylercipriani.com'
    fqdn = '%s.%s' % (sub_domain, domain)

    zone = route53.get_zone(domain)
    a_rec = zone.get_a(fqdn)
    new_ip = get_ip()

    if (a_rec):
        if new_ip == a_rec.resource_records[0]:
            print '%s is current. (%s)' % (fqdn, new_ip)
            sys.exit(0)

        try:
            zone.update_a(fqdn, new_ip, 900)
        except DNSServerError:
            zone.add_a(fqdn, new_ip, 900)

    else:
        zone.add_a(fqdn, new_ip, 900)

if __name__ == '__main__':
    main()