AWSTemplateFormatVersion: "2010-09-09"
Description: ""
Resources:
  SnsTopicMetricFilterCloudWatchAlarm:
    Type: "AWS::SNS::Topic"
    Properties:
      Subscription:
        - Endpoint: "email@example.com"
          Protocol: "email"
      TopicName: "alarm-action"
  CloudWatchAlarm:
    Type: "AWS::CloudWatch::Alarm"
    Properties:
      AlarmName: "igw_changes"
      AlarmDescription: "A CloudWatch Alarm that triggers when changes are made to an Internet Gateway in a VPC."
      MetricName: "GatewayEventCount"
      Namespace: "CloudTrailMetrics"
      Statistic: "Sum"
      Period: "300"
      EvaluationPeriods: "1"
      Threshold: "1"
      ComparisonOperator: "GreaterThanOrEqualToThreshold"
      AlarmActions:
        - Ref: "SnsTopicMetricFilterCloudWatchAlarm"
      TreatMissingData: "notBreaching"
  MetricFilterCloudWatchAlarm:
    Type: "AWS::Logs::MetricFilter"
    Properties:
      LogGroupName: ""
      FilterPattern: "{ ($.eventName = CreateCustomerGateway) || ($.eventName = DeleteCustomerGateway) || ($.eventName = AttachInternetGateway) || ($.eventName = CreateInternetGateway) || ($.eventName = DeleteInternetGateway) || ($.eventName = DetachInternetGateway) }"
      MetricTransformations:
        - MetricValue: "1"
          MetricNamespace: "CloudTrailMetrics"
          MetricName: "GatewayEventCount"
Parameters: {}
Metadata: {}
Conditions: {}