AWS证书管理器中的证书是有期限的，如果没有及时续订，网站的HTTPS连接可能会出现问题。CloudFront分发缓存也可能会出现问题，所以需要对这些证书进行自动续订。

可以使用AWS Lambda和CloudWatch事件将证书自动续订和更新与CloudFront分发关联。例如，下面的示例代码演示了如何设置Lambda函数，在证书到期前30天自动续订证书。

import boto3
from datetime import datetime, timedelta

CERTIFICATE_ARN = "arn:aws:acm:region:account_id:certificate/certificate_id"
DAYS_BEFORE_EXPIRATION = 30

def lambda_handler(event, context):
    client = boto3.client('acm')

    # Get the certificate and its expiration date
    cert = client.describe_certificate(CertificateArn=CERTIFICATE_ARN)
    expiration_date = cert['Certificate']['NotAfter']

    # Calculate the number of days until the certificate expires
    days_to_expiration = (expiration_date - datetime.utcnow().replace(tzinfo=None)).days

    if days_to_expiration <= DAYS_BEFORE_EXPIRATION:
        # Renew the certificate
        response = client.renew_certificate(CertificateArn=CERTIFICATE_ARN)
        print("Certificate renewed successfully.")
    else:
        print("Certificate is not due for renewal yet.")

然后，可以将该Lambda函数与CloudWatch事件结合使用，以便在证书到期前30天自动续订证书。例如，下面的示例代码演示了如何设置CloudWatch事件规则，每天在UTC时间11点运行Lambda函数。

import boto3

rule_name = "RenewCertificateRule"
lambda_name = "RenewCertificateFunction"
schedule_expression = "cron(0 11 * * ? *)"
target_arn = "arn:aws:lambda:region:account_id:function:" + lambda_name

cloudwatch = boto3.client('events')

response = cloudwatch.put_rule(
    Name=rule_name,
    ScheduleExpression=schedule_expression,
    State='ENABLED'
)

response = cloudwatch.put_targets(
    Rule=rule_name,
    Targets=[
        {
            'Id': '1',
            'Arn': target_arn,
        }
    ]
)

通过此方法，证书将自动更新，并且与CloudFront分发相关联的证书也将更新。