title: Is it possible to create a SNS subscription with CloudFormation without creating a topic?
body: <p>Is it possible to create a 'Subscription' resource in a AWS CloudFormation JSON template without creating a new <code>AWS::SNS::Topic</code>?</p>
  
  <p>In my case, the topic is created outside of the CloudFormation script, and I would like to create some subscriptions to it, involving resources created within the script.</p>
  
  <p>I.E.</p>
  
  <pre class="lang-or-tag-here prettyprint-override"><code>   "DbfExtractQueue": {
          "Type": "AWS::SQS::Queue"
      },
  
      "EtlSubscription": {
          "Type": "AWS::SNS::Subscription",
          "Properties": {
              "Endpoint": { "Fn::GetAtt": ["DbfExtractQueue", "Arn"] },
              "Protocol": "sqs",
              "TopicArn": { "Ref": "EtlNotificationTopicARN" }
          }
      },
  </code></pre>
  
  <p>The EtlNotificationTopicARN is passed into the script and represents a SNS topic ARN.</p>