Renew current EIP of an AWS EC2 Instance

renew_aws_ec2_eip.py

import boto3
import urllib.request
from botocore.exceptions import ClientError


METADATA_URL = 'http://169.254.169.254/latest/meta-data'

instance_id = urllib.request.urlopen(METADATA_URL + '/instance-id').read().decode()
current_eip = urllib.request.urlopen(METADATA_URL + '/public-ipv4').read().decode()

try:
    ec2 = boto3.client('ec2')

    # Alocar um novo EIP
    allocation = ec2.allocate_address(Domain='vpc')
    new_eip = allocation['PublicIp']
    print("Novo EIP alocado: %s" % (new_eip))
    
    # Disassocia o EIP atual
    response = ec2.describe_addresses(PublicIps=[current_eip])
    allocation_id = response['Addresses'][0]['AllocationId']
    association_id = response['Addresses'][0]['AssociationId']
    response = ec2.disassociate_address(AssociationId=association_id)
    
    # Liberar o EIP atual
    response = ec2.release_address(AllocationId=allocation_id)
    print("EIP antigo %s liberado" % (current_eip))

    # Associar o novo EIP a instância corrente
    response = ec2.associate_address(
        AllocationId=allocation['AllocationId'],
        InstanceId=instance_id)
    print("EIP associado a instância %s." % (instance_id))

except ClientError as e:
    print(e)