Set a domain to an ELB

alias.py

import boto
from boto.route53.record import ResourceRecordSets
import json


subdomain = 'twitter'
primary_domain = 'tryambition.com'
load_balancer_name = 'elb-2'

elb_conn = boto.connect_elb()
r53_conn = boto.connect_route53()

zone = r53_conn.get_zone(primary_domain)
a_name = '{}.{}'.format(subdomain, primary_domain)

elb = elb_conn.get_all_load_balancers(load_balancer_names=[load_balancer_name])[0]

new_rrs = ResourceRecordSets(connection=r53_conn,
                             hosted_zone_id=zone.id,
                             comment='Adding DNS to ELB')
new_rrs.add_change(action='CREATE',
                   name=a_name,
                   type='A',
                   alias_dns_name=elb.dns_name,
                   alias_hosted_zone_id=elb.canonical_hosted_zone_name_id)
commit_dict = new_rrs.commit()
print json.dumps(commit_dict, indent=4)

output

{
    "ChangeResourceRecordSetsResponse": {
        "ChangeInfo": {
            "Status": "PENDING", 
            "Comment": "Adding DNS to ELB", 
            "SubmittedAt": "2013-11-26T15:39:40.764Z", 
            "Id": "/change/D3B7418OFQCOHR"
        }
    }
}