Custom resource response objects - AWS CloudFormation
Custom resource provider response fields

Custom resource response objects

This topic describes the properties of the response object for a CloudFormation custom resource.

For an introduction to custom resources and how they work, see Create custom provisioning logic with custom resources.

Custom resource provider response fields

The following are properties that the custom resource provider includes when it sends the JSON file to the presigned URL. For more information about uploading objects by using presigned URLs, see Uploading objects with presigned URLs in the Amazon Simple Storage Service User Guide.

Note

The total size of the response body can't exceed 4096 bytes.

Status

The status value sent by the custom resource provider in response to an AWS CloudFormation-generated request.

Must be either SUCCESS or FAILED.

Required: Yes

Type: String

Reason

Describes the reason for a failure response.

Required: Required if Status is FAILED. It's optional otherwise.

Type: String

PhysicalResourceId

This value should be an identifier unique to the custom resource vendor, and can be up to 1 KB in size. The value must be a non-empty string and must be identical for all responses for the same resource.

The value returned for a PhysicalResourceId can change custom resource update operations. If the value returned is the same, it is considered a normal update. If the value returned is different, AWS CloudFormation recognizes the update as a replacement and sends a delete request to the old resource. For more information, see AWS::CloudFormation::CustomResource.

Required: Yes

Type: String

StackId

The Amazon Resource Name (ARN) that identifies the stack that contains the custom resource. This response value should be copied verbatim from the request.

Required: Yes

Type: String

RequestId

A unique ID for the request. This response value should be copied verbatim from the request.

Required: Yes

Type: String

LogicalResourceId

The template developer-chosen name (logical ID) of the custom resource in the AWS CloudFormation template. This response value should be copied verbatim from the request.

Required: Yes

Type: String

NoEcho

Optional. Indicates whether to mask the output of the custom resource when retrieved by using the Fn::GetAtt function. If set to true, all returned values are masked with asterisks (*****), except for those stored in the Metadata section of the template. AWS CloudFormation does not transform, modify, or redact any information you include in the Metadata section. The default value is false.

For more information about using NoEcho to mask sensitive information, see the Do not embed credentials in your templates best practice.

Required: No

Type: Boolean

Data

Optional. The custom resource provider-defined name-value pairs to send with the response. You can access the values provided here by name in the template with Fn::GetAtt.

Important

If the name-value pairs contain sensitive information, you should use the NoEcho field to mask the output of the custom resource. Otherwise, the values are visible through APIs that surface property values (such as DescribeStackEvents).

Required: No

Type: JSON object