ec2_start_and_route53.py

#!/usr/bin/python
'''
This script finds an instance by its ID and starts it.
Then, it finds out its public IP address and changes Route53 'A' record.
'''

import boto3

def instance_start(id):
    '''
    Starts an EC2 instance and waits until it's state is running.
    '''
    ec2 = boto3.resource('ec2')
    instance = ec2.Instance(id)
	# start instance
    instance.start()
    print('Starting instance ' + id)
	# wait until 'running' state
    instance.wait_until_running()

def find_ip(id):
    '''
    Finds a public IP address based on instance ID.
    Returns a public IP address.
    '''
    ec2 = boto3.resource('ec2')
    instance = ec2.Instance(id)
    ip = instance.public_ip_address
    return ip

def change_route53_record(zone_id, domain, ip):
    '''
    Changes Route53 type A record.
    '''
    r53 = boto3.client('route53')
    r53.change_resource_record_sets(
        HostedZoneId=zone_id,
        ChangeBatch={
            'Comment': 'test',
            'Changes': [
                {
                    'Action': 'UPSERT',
                    'ResourceRecordSet': {
                        'Name': domain,
                        'ResourceRecords': [
                            {
                                'Value': ip
                            }
                        ],
                    'Type': 'A',
                    'TTL': 300
                    }
                },
            ]
        }
    )
    
# set instance ID
instance_id = '' # Instance ID, e.g. 'i-0111112233'
# set Hosted Zone ID
zone_id = '' # Hosted Zone ID, e.g. 'ZBDAAABBBCCC'
# domain
domain = '' # Domain, e.g. technoff.eu

# start instance
instance_start(instance_id)
# find the public IP address
ip_address = find_ip(instance_id)
# change 'A' record
change_a_record = change_route53_record(zone_id, domain, ip_address)
print(domain + ' record was changed to: ' + ip_address)