Update Route53 from ISC DHCP Server when a new lease is created via python and boto3

dhcpd.conf

# add to dhcpd.conf
# make sure the dhcpd user has permission to execute the script
on commit {
  set ClientName = pick-first-value(option fqdn.hostname, option host-name, "unknown-hostname");
  set ClientIp = binary-to-ascii(10, 8, ".", leased-address);
  set ClientMac = binary-to-ascii(16, 8, ":", substring(hardware, 1, 6));
  execute("/opt/dhcpd-hooks/dhcp_event_hook.py", "commit", ClientName, ClientIp, ClientMac);
}

dhcpd_event_hook.py

#!/usr/bin/env python

import json
import os
import sys
import boto3


def main():
    arg_names = ['action', 'name', 'ip', 'mac']
    args = []
    if len(sys.argv) > 1:
        args = sys.argv[1:]

    params = dict(zip(arg_names, args))

    if params["action"] == "commit":
        update_dns(params)


def update_dns(params):
    if params["name"] == "unknown-hostname":
        print("unknown-hostname, DNS update aborted")
        return 1

    client = boto3.client('route53',
        aws_access_key_id="<< key >>",
        aws_secret_access_key="<< secret >>")
    response = client.change_resource_record_sets(
        HostedZoneId='<< get hosted zone ID from AWS >>',
        ChangeBatch={
            'Comment': 'updated by DHCP',
            'Changes': [
                {
                    'Action': 'UPSERT',
                    'ResourceRecordSet': {
                        'Name': params["name"] + '.int.labsgroup.com',
                        'Type': 'A',
                        'TTL': 120,
                        'ResourceRecords': [
                            {
                                'Value': params["ip"]
                            },
                        ]
                    }
                },
            ]
        }
    )


if __name__ == '__main__':
    main()