AWS::CloudFormation::WaitConditionHandle
Important
For Amazon EC2 and Auto Scaling resources, we recommend that you use a CreationPolicy
attribute instead of wait conditions. Add a CreationPolicy
attribute to those resources, and use the
cfn-signal helper script to signal when an instance creation process has completed successfully.
For more information, see Deploying applications on Amazon EC2 with AWS CloudFormation.
The AWS::CloudFormation::WaitConditionHandle
type has no properties. When you reference the
WaitConditionHandle
resource by using the Ref
function, AWS 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.
Important
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.
Note
Updates aren't supported for this resource.
Syntax
To declare this entity in your AWS CloudFormation template, use the following syntax:
JSON
{ "Type" : "AWS::CloudFormation::WaitConditionHandle }
YAML
Type: AWS::CloudFormation::WaitConditionHandle
Return values
Fn::GetAtt
The Fn::GetAtt
intrinsic function returns a value for a specified attribute of this type. The following are the available attributes and sample return values.
For more information about using the Fn::GetAtt
intrinsic function, see Fn::GetAtt
.
Id
-
A unique identifier for the resource.
See also
-
For information about how to use wait conditions, see Creating wait conditions in a template.