CfnWaitConditionHandle

The `AWS::CloudFormation::WaitConditionHandle` type has no properties. When you reference the `WaitConditionHandle` resource by using the `Ref` function, CloudFormation returns a presigned URL. You pass this URL to applications or scripts that are running on your Amazon EC2 instances to send signals to that URL. An associated `AWS::CloudFormation::WaitCondition` resource checks the URL for the required number of success signals or for a failure signal. For more information, see [Create wait conditions in a CloudFormation template](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-waitcondition.html) in the *CloudFormation User Guide* . Anytime you add a `WaitCondition` resource during a stack update or update a resource with a wait condition, you must associate the wait condition with a new `WaitConditionHandle` resource. Don't reuse an old wait condition handle that has already been defined in the template. If you reuse a wait condition handle, the wait condition might evaluate old signals from a previous create or update stack command. Updates aren't supported for this resource.