main.py

from __future__ import print_function

import os
import boto3
import pprint
import logging
import datetime

SPOT_FLEET_REQUEST_ID = os.environ['SpotFleetRequestId']
SNS_TOPIC_ARN = os.environ['SnsTopicArn']
QUEUE_URL = os.environ['QueueUrl']
QUEUE_NAME = os.environ['QueueName']

logger = logging.getLogger()
logger.setLevel(logging.INFO)
pp = pprint.PrettyPrinter(indent=4)

def handle(event, context):
    ec2_client = boto3.client('ec2')
    cloudwatch_client = boto3.client('cloudwatch', region_name='ap-northeast-1')

    queue_metric = cloudwatch_client.get_metric_statistics(
                                Namespace='AWS/SQS',
                                MetricName='ApproximateNumberOfMessagesVisible',
                                Dimensions=[
                                    {
                                        'Name': 'QueueName',
                                        'Value': QUEUE_NAME
                                    }
                                ],
            StartTime=datetime.datetime.now() - datetime.timedelta(minutes=60),
            EndTime=datetime.datetime.now(),
            Period=300,
            Statistics=['Average'])
    avg = 0
    for datapoint in queue_metric['Datapoints']:
        avg += datapoint['Average']
    else:
        message_num = avg / len(queue_metric['Datapoints'])
    pp.pprint(queue_metric)
    logger.info(message_num)
    #resp = client.modify_spot_fleet_request(
    #        SpotFleetRequestId=SPOT_FLEET_REQUEST_ID,
    #        TargetCapacity=3
    #        )
    #logger.info(resp)