Generated Amazon CloudFormation resources - Amazon Serverless Application Model
Referencing generated Amazon CloudFormation resourcesGenerated Amazon CloudFormation resource scenarios
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Generated Amazon CloudFormation resources

This section provides details on the Amazon CloudFormation resources that are created when Amazon SAM processes your Amazon template. The set of Amazon CloudFormation resources that Amazon SAM generates differs depending on the scenarios you specify. A scenario is the combination of Amazon SAM resources and properties specified in your template file. You can reference the generated Amazon CloudFormation resources elsewhere within your template file, similar to how you reference resources that you declare explicitly in your template file.

For example, if you specify an AWS::Serverless::Function resource in your Amazon SAM template file, Amazon SAM always generates an AWS::Lambda::Function base resource. If you also specify the optional AutoPublishAlias property, Amazon SAM additionally generates AWS::Lambda::Alias and AWS::Lambda::Version resources.

This section lists the scenarios and the Amazon CloudFormation resources that they generate, and shows how to reference the generated Amazon CloudFormation resources in your Amazon SAM template file.

Referencing generated Amazon CloudFormation resources

You have two options for referencing generated Amazon CloudFormation resources within your Amazon SAM template file, by LogicalId or by referenceable property.

Referencing generated Amazon CloudFormation resources by LogicalId

The Amazon CloudFormation resources that Amazon SAM generates each have a LogicalId, which is an alphanumeric (A-Z, a-z, 0-9) identifier that is unique within a template file. Amazon SAM uses the LogicalIds of the Amazon SAM resources in your template file to construct the LogicalIds of the Amazon CloudFormation resources it generates. You can use the LogicalId of a generated Amazon CloudFormation resource to access properties of that resource within your template file, just like you would for an Amazon CloudFormation resource that you have explicitly declared. For more information about LogicalIds in Amazon CloudFormation and Amazon SAM templates, see Resources in the Amazon CloudFormation User Guide.

Note

The LogicalIds of some generated resources include a unique hash value to avoid namespace clashes. The LogicalIds of these resources are derived when the stack is created. You can retrieve them only after the stack has been created using the Amazon Web Services Management Console, Amazon CLI, or one of the Amazon SDKs. We don't recommend referencing these resources by LogicalId because the hash values might change.

Referencing generated Amazon CloudFormation resources by referenceable property

For some generated resources, Amazon SAM provides a referenceable property of the Amazon SAM resource. You can use this property to reference a generated Amazon CloudFormation resource and its properties within your Amazon SAM template file.

Note

Not all generated Amazon CloudFormation resources have referenceable properties. For those resources, you must use the LogicalId.

Generated Amazon CloudFormation resource scenarios

The following table summarizes the Amazon SAM resources and properties that make up the scenarios that generate Amazon CloudFormation resources. The topics in the Scenarios column provide details about the additional Amazon CloudFormation resources that Amazon SAM generates for that scenario.

Amazon SAM resource Base Amazon CloudFormation resource Scenarios
AWS::Serverless::Api AWS::ApiGateway::RestApi
AWS::Serverless::Application AWS::CloudFormation::Stack

  • Other than generating the base Amazon CloudFormation resource, there are no additional scenarios for this serverless resource.
AWS::Serverless::Function AWS::Lambda::Function
AWS::Serverless::HttpApi AWS::ApiGatewayV2::Api
AWS::Serverless::LayerVersion AWS::Lambda::LayerVersion

  • Other than generating the base Amazon CloudFormation resource, there are no additional scenarios for this serverless resource.
AWS::Serverless::SimpleTable AWS::DynamoDB::Table

  • Other than generating the base Amazon CloudFormation resource, there are no additional scenarios for this serverless resource.
AWS::Serverless::StateMachine AWS::StepFunctions::StateMachine
Topics