Bringing existing resources into CloudFormation management - AWS CloudFormation
Resource import overviewResource import validationResource import status codesConsiderations during an import operationGetting started with resource import

Bringing existing resources into CloudFormation management

If you created an AWS resource outside of AWS CloudFormation management, you can bring this existing resource into AWS CloudFormation management using resource import. You can manage your resources using AWS CloudFormation regardless of where they were created without having to delete and re-create them as part of a stack.

For a list of AWS resources that support import operations, see Resources that support import operations.

Resource import overview

During an import operation, you create a change set that imports your existing resources into a stack or creates a new stack from your existing resources. You provide the following during import.

  • A template that describes the entire stack, including both the original stack resources and the resources you're importing. Each resource to import must have a DeletionPolicy attribute.

  • Identifiers for the resources to import. You provide two values to identify each target resource.

    • An identifier property. This is a resource property that can be used to identify each resource type. For example, an AWS::S3::Bucket resource can be identified using its BucketName.

    • An identifier value. This is the target resource's actual property value. For example, the actual value for the BucketName property might be MyS3Bucket.

Note

AWS CloudFormation only supports one level of nesting using resource import. This means that you can't import a stack into a child stack or import a stack that has children.

Resource import validation

During an import operation, CloudFormation performs the following validations.

  • The resource to import exists.

  • The properties and configuration values for each resource to import adhere to the resource type schema, which defines its accepted properties, required properties, and supported property values.

  • The required properties are specified in the template. Required properties for each resource type are listed in the Resource and property reference.

  • The resource to import doesn't belong to another stack in the same Region.

CloudFormation doesn't check that the template configuration matches the actual configuration of resource properties.

Important

Verify that resources and their properties defined in the template match the intended configuration of the resource import to avoid unexpected changes.

Resource import status codes

This table describes the various status types used with resource import.

Import operation status Description

IMPORT_IN_PROGRESS

The import operation is in progress.

IMPORT_COMPLETE

The import operation completed for all resources in the stack.

IMPORT_ROLLBACK_IN_PROGRESS

The rollback import operation is rolling back the previous template configuration.

IMPORT_ROLLBACK_FAILED

The import rollback operation failed.

IMPORT_ROLLBACK_COMPLETE

The import rolled back to the previous template configuration.

Considerations during an import operation

  • After the import is complete and before performing subsequent stack operations, we recommend running drift detection on imported resources. Drift detection ensures that the template configuration matches the actual configuration.

  • Import operations don't allow new resource creations, resource deletions, or changes to property configurations.

  • Each resource to import must have a DeletionPolicy attribute for the import operation to succeed. The DeletionPolicy can be set to any possible value. Only target resources need a DeletionPolicy. Resources that are already part of the stack don't need a DeletionPolicy.

  • You can't import the same resource into multiple stacks.

  • You can use the cloudformation:ImportResourceTypes IAM policy condition to control which resource types users can work with during an import operation.

  • The AWS CloudFormation stack limits apply when importing resources. For more information on limits, see AWS CloudFormation limits.

Getting started with resource import