Data of CloudWatch (CPUUtilization of EC2) is put in DynamoDB. Please running in AWS Lambda every hour 10 minutes.

cloudwatch-to-dynamodb.py

from __future__ import print_function

import boto3
import pytz
from datetime import datetime
from dateutil.relativedelta import relativedelta

print('Loading function')

def lambda_handler(event, context):

    try:
        tokyo = pytz.timezone('Asia/Tokyo')
        
        table_name = 'ec2_cpuutilization'

        sts = boto3.client('sts')
        result = sts.assume_role(
            RoleArn = 'arn:aws:iam::XXXXXXXXXXXX:role/DevReadOnlyRole',
            RoleSessionName = 'kokeshi',
        )

        credentials = result['Credentials']

        session = boto3.Session(
            aws_access_key_id = credentials['AccessKeyId'],
            aws_secret_access_key = credentials['SecretAccessKey'],
            aws_session_token = credentials['SessionToken'],
        )

        filters = [
            {
                'Name': 'tag:ec2_name',
                'Values': [
                    'www01',
                ],
            },
        ]

        ec2 = session.client('ec2')

        instance = ec2.describe_instances(
            Filters = filters,
        )

        instance_id = instance['Reservations'][0]['Instances'][0]['InstanceId']

        an_hour_ago = datetime.now(tokyo) - relativedelta(hours = 1)
        eighty_minutes_ago = datetime.now(tokyo) - relativedelta(minutes = 80)
        now = datetime.now(tokyo)

        cloudwatch_client = session.client('cloudwatch')
        
        result = cloudwatch_client.get_metric_statistics(
            Namespace = 'AWS/EC2',
            MetricName = 'CPUUtilization',
            Dimensions = [
                {
                    'Name': 'InstanceId',
                    'Value': instance_id,
                },
            ],
            StartTime = eighty_minutes_ago,
            EndTime = now,
            Period = 60,
            Statistics = [
                'Maximum',
            ],
            Unit = 'Percent',
        )

        day = an_hour_ago.strftime('%Y/%m/%d')
        hour = an_hour_ago.strftime('%H')

        save_data = {}
        for i in range(60):
            minute = '%02d' % (i)
            time = hour + ':' + minute + ':00'
            save_data[time] = 0

        datapoints = result['Datapoints']

        for datapoint in datapoints:
            tmp_timestamp = datapoint['Timestamp'] + relativedelta(hours = 9)
            tmp_date = tmp_timestamp.strftime('%H:%M:%S')
            tmp_hour = tmp_timestamp.strftime('%H')

            if hour == tmp_hour:
                save_data[tmp_date] = datapoint['Maximum']

        dynamodb = boto3.resource('dynamodb')

        table = dynamodb.Table(table_name)
        for key, value in save_data.items():
            result = table.put_item(
                Item = {
                        'day' : str(day),
                        'time' : str(key),
                        'percent' : str(value),
                    },
                )

    except Exception as e:
        print(e)
        print('NG')