CW-Alarm_memory-Update-Boto3

import boto3
import json

def lambda_handler(event, context):
    print("Received event: " + json.dumps(event))
    if event['detail']['eventName'] == 'ModifyInstanceAttribute' and 'instanceType' in event['detail']['requestParameters']:
        instance_id = event['detail']['requestParameters']['instanceId']
        instance_type = event['detail']['requestParameters']['instanceType']['value']
        cw = boto3.client('cloudwatch')
        alarms = cw.describe_alarms()
        for alarm in alarms['MetricAlarms']:
            if alarm['Dimensions'][0]['Value'] == instance_id and alarm['Namespace'] == 'CWAgent' and alarm['MetricName'] == 'Memory % Committed Bytes In Use':
                alarm_name = alarm['AlarmName']
                print("Found alarm: " + alarm_name)
                response = cw.put_metric_alarm(
                    AlarmName=alarm_name,
                    ComparisonOperator='GreaterThanThreshold',
                    EvaluationPeriods=1,
                    MetricName='Memory % Committed Bytes In Use',
                    Namespace='CWAgent',
                    Period=300,
                    Statistic='Average',
                    Threshold=80.0,
                    ActionsEnabled=False,
                    AlarmDescription='Alarm when server Memory exceeds 80%',
                    Dimensions=[
                        {
                            'Name': 'InstanceId',
                            'Value': instance_id
                        },
                        {
                            'Name': 'InstanceType',
                            'Value': instance_type
                        },
                    ],
                )
                print("Updated alarm: " + alarm_name)