Python script to bulk update DNS entries in Route53

update_route53_dns.py

#!/usr/bin/env python

"""
Bulk Update DNS on AWS Route53
"""
import argparse
import sys
import boto3

parser = argparse.ArgumentParser()

parser.add_argument("--zoneId", type=str, default="", help="Route53 Zone Id, recommend setting this as an environment variable")
parser.add_argument("--hostname", type=str, default="", help="The hostname to update example.domain.com")
parser.add_argument("--dns", type=str, default="", help="The new dns value")

args = parser.parse_args()

route53 = boto3.client('route53')
zoneid = args.zoneId
hostname = args.hostname
CNAME = args.dns


if not zoneid or not hostname or not CNAME:
  print("Please provide a zone id, hostname and new dns")
  return


#
# updatedns - Updates DNS for a hos name
#
def updatedns(hostname, newdns):
    # Add trailing dot to hostname if it doesn't have one
    if hostname[-1:] != ".":
        hostname += "."

    print('Hostname: %s' % hostname)
    print('Current DNS: %s' % newdns)

    # If you only have one hosted zone, you can do something like this to look in the zone
    # Initialize the connection to AWS Route53
    # route53 = Route53Connection()
    # route53zones = route53.get_all_hosted_zones()
    # route53zones = route53.list_resource_record_sets(HostedZoneId=)

    sets = route53.list_resource_record_sets(HostedZoneId=zoneid)

    for rset in sets['ResourceRecordSets']:
        if rset['Name'] == hostname and rset['Type'] == 'CNAME':
            curdnsrecord = rset['ResourceRecords']
            print(curdnsrecord)
            if type(curdnsrecord) in [list, tuple, set]:
                for record in curdnsrecord:
                    curdns = record
            # print('Current DNS CNAME: %s' % curdns)
            curttl = rset['TTL']
            # print('Current DNS TTL: %s' % curttl)

            if curdns != newdns:
                # UPSERT the record
                print('Updating %s' % hostname)
                route53.change_resource_record_sets(
                  HostedZoneId=zoneid,
                  ChangeBatch={
                    'Changes': [
                      {
                        'Action': 'UPSERT',
                        'ResourceRecordSet': {
                          'Name': hostname,
                          'Type': 'CNAME',
                          'TTL': curttl,
                          'ResourceRecords': [
                            {
                              'Value': newdns
                            }
                          ]
                        }
                      }
                    ]
                  }
                )
                
try:
    updatedns(hostname, CNAME)
except:
    print('DNS Update failed. Check credentials or IAM roles.')