dnsmapping.py

import boto3


def map_ert_domain(stackname, domain, lbname=None,
                   route53=None, elb=None, names=None):
    """
    maps *.domain, *.system.domain, *.apps.domain
    to stackname-pcf-elb load balancer
    """
    route53 = route53 or boto3.client('route53')
    elb = elb or boto3.client('elb')
    prefixes = ["", "*.", "*.system.", "*.apps."]
    names = names or [prefix + domain for prefix in prefixes]

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

    zones = [z for z in route53.list_hosted_zones()['HostedZones'] if domain.endswith(z['Name'])]
    for zone in zones:
        # based on standard naming
        if zone['Config']['PrivateZone'] == False:
            lbname = stackname + "-pcf-elb"
        if zone['Config']['PrivateZone'] == True:
            lbname = stackname + "-pcf-elb-in"
        resp = elb.describe_load_balancers(
            LoadBalancerNames=[lbname])

        if len(resp.get('LoadBalancerDescriptions', [])) == 0:
            raise Exception(lbname + " Loadbalacer could not be found")

        dnsname = resp['LoadBalancerDescriptions'][0]['DNSName']

        if not zones:
            print domain + " Is not managed in route53"
            print "Manually map {} <-- {}".format(dnsname, names)
            return

        # ensure names are unique
        names = set(names)

        changes = [
            {
                'Action': 'UPSERT',
                'ResourceRecordSet': {
                    'Name': name,
                    'Type': 'CNAME',
                    'TTL': 300,
                    'ResourceRecords': [
                        {
                            'Value': dnsname
                        },
                    ],
                }
            } for name in names]

        route53.change_resource_record_sets(
            HostedZoneId=zone['Id'],
            ChangeBatch={
                'Comment': "for stack="+stackname,
                'Changes': changes
            })