Internet Gateways Attached to Authorized VPCs Only Check

AWSTemplateFormatVersion: '2010-09-09'
Description: ''
Resources:
  ConfigRule:
    Type: 'AWS::Config::ConfigRule'
    Properties:
      ConfigRuleName: internet-gateway-authorized-vpc-only
      Description: >-
        A config rule that checks that Internet gateways (IGWs) are only
        attached to an authorized Amazon Virtual Private Cloud (VPCs). The rule
        is NON_COMPLIANT if IGWs are not attached to an authorized VPC.
      Scope:
        ComplianceResourceTypes:
          - 'AWS::EC2::InternetGateway'
      Source:
        Owner: AWS
        SourceIdentifier: INTERNET_GATEWAY_AUTHORIZED_VPC_ONLY
Parameters: {}
Metadata: {}
Conditions: {}