Bringing existing resources into CloudFormation management
If you created an Amazon resource outside of Amazon CloudFormation management, you can bring this existing resource
into Amazon CloudFormation management using resource import
. You can manage your resources using Amazon CloudFormation regardless of
where they were created without having to delete and re-create them as part of a stack.
Note
For more information on generating a template from existing resources, see Generating templates for existing resources.
For a list of Amazon resources that support import operations, see Resource type support.
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 aDeletionPolicy 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 itsBucketName
. -
An identifier value. This is the target resource's actual property value. For example, the actual value for the
BucketName
property might beMyS3Bucket
.
-
Note
Amazon 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 Amazon resource and property types 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 |
---|---|
|
The import operation is in progress. |
|
The import operation completed for all resources in the stack. |
|
The rollback import operation is rolling back the previous template configuration. |
|
The import rollback operation failed. |
|
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. For more information, see Detect drift on an entire CloudFormation stack.
-
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. TheDeletionPolicy
can be set to any possible value. Only target resources need aDeletionPolicy
. Resources that are already part of the stack don't need aDeletionPolicy
. -
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. For more information, see Amazon CloudFormation conditions. -
The Amazon CloudFormation stack limits apply when importing resources. For more information on limits, see Amazon CloudFormation quotas.