title: Cloudformation Trigger Event for Existing bucket
body: <p>I am trying to write a cloudformation template which involves adding an event to a bucket to trigger a lambda function. </p>
  
  <p>I know i can use code such as the below to create a bucket and an event at the same time but my bucket already exists and i don't want another one so is there a way of creating an event for an existing bucket within cloud formation?</p>
  
  <pre><code>"EncryptionServiceBucket" : {
    "Type" : "AWS::S3::Bucket",
    "Properties" : {
      "BucketName" : { "Fn::Sub" : "${User}-encryption-service" },
      "NotificationConfiguration" : {
        "LambdaConfigurations" : [{
          "Function" : { "Ref" : "LambdaDeploymentArn" },
          "Event" : "s3:ObjectCreated:*",
          "Filter" : {
            "S3Key" : {
              "Rules" : [{
                "Name" : "suffix",
                "Value" : "zip"
              }]
            }
          }
        }]
      }
    }
  }
  </code></pre>