check-deleted-amis.py

# -*- coding: utf-8 -*-
from __future__ import print_function
import json

import boto3

# SNS Config
sns_topic_arn = "arn:aws:sns:eu-west-1:AWS-ACCOUNT-ID:SNS-TOPIC"
sns_subject = "ASGs Missing AMIs"


def lambda_handler(event, context):
    failures = collect_launch_configs(get_regions())
    if bool(failures):
        send_sns_message(failures)


def get_regions():
    regions = {}
    for region in boto3.client('ec2').describe_regions()['Regions']:
        regions[region['RegionName']] = []
    return regions


def message(content):
    return "This is a report of regions that have Auto Scaling groups "\
           "deployed that include a launch configuration that points to an "\
           "AMI that is not available:\n\n%s" % (json.dumps(content, indent=4))


def send_sns_message(failures):
    client = boto3.client('sns')
    client.publish(
        TopicArn=sns_topic_arn,
        Message=message(failures),
        Subject=sns_subject
    )


def collect_launch_configs(regions):
    # launch_configs = regions
    failures = {}

    for region in regions:
        asg_client = boto3.client('autoscaling', region_name=region)
        ec2_client = boto3.client('ec2', region_name=region)
        # We get all images here because we dont want to do a single
        # api call for every launch configuration
        res = ec2_client.describe_images(
            Filters=[
                {
                    'Name': 'state',
                    'Values': ['available']
                }
            ],
            Owners=['self']
        )['Images']
        our_images = [x['ImageId'] for x in res]

        paginator = asg_client.get_paginator('describe_launch_configurations')
        lcs = paginator.paginate().build_full_result()
        for lc in lcs['LaunchConfigurations']:
            if not lc['ImageId'] in our_images:
                if region in failures:
                    failures[region].append({"LaunchConfigurationName":
                                             lc['LaunchConfigurationName'],
                                             "ImageId": lc['ImageId']})
                else:
                    failures[region] = [{"LaunchConfigurationName":
                                         lc['LaunchConfigurationName'],
                                         "ImageId": lc['ImageId']}]
    return failures