title: How to configure StreamArn of existing dynamodb table
body: <p>I'm creating serverless framework project.</p>
  
  <p>DynamoDB table is created by other CloudFormation Stack.</p>
  
  <p>How I can refer existing dynamodb table's StreamArn in <code>serverless.yml</code></p>
  
  <p>I have configuration as below</p>
  
  <pre><code>resources:
    Resources:
      MyDbTable: //'arn:aws:dynamodb:us-east-2:xxxx:table/MyTable'
  provider:
    name: aws
    ...
    onDBUpdate:
      handler: handler.onDBUpdate
      events:
        - stream:
          type: dynamodb
          arn:
            Fn::GetAtt:
              - MyDbTable
              - StreamArn
  </code></pre>