add ec2 instances with tag Name in Route53 Domain

add_ec2_to_route53.py

import os
import boto3

HOSTED_ZONE_ID = "ABCDEF123456789"
DOMAIN_NAME = ".example.lan."

def lambda_handler():
    # Setup Boto3 client
    boto3.setup_default_session(region_name='us-east-1')
    ec2 = boto3.client("ec2")
    dns = boto3.client("route53")
    
    reservations = ec2.describe_instances()
    for reservation in reservations['Reservations']:
        for instance in reservation['Instances']:
            register_instance(ec2, dns, instance)
            
def register_instance(ec2, dns, instance):
    # Get instance's name
    tags = instance['Tags']
    name = list(filter(lambda x: x['Key'] == 'Name', tags))[0]['Value']
    new_ip = instance['PrivateIpAddress']
    
    # Change / Create DNS Record
    dns.change_resource_record_sets(
        HostedZoneId=HOSTED_ZONE_ID,
        ChangeBatch={
            'Changes': [
                {
                    'Action': 'UPSERT',
                    'ResourceRecordSet': {
                        'Name': name + DOMAIN_NAME,
                        'Type': 'A',
                        'TTL': 300,
                        'ResourceRecords': [
                            {
                                'Value': new_ip
                            },
                        ]
                    }
                }
            ]
        })
        
lambda_handler()