Creating a stack from existing resources
This topic shows you how to create a stack from existing Amazon resources by describing them in a template. To instead scan for existing resources and automatically generate a template that you can use to import existing resources into CloudFormation or replicate resources in a new account, see Generating templates for existing resources.
Prerequisites
Before you begin, you must have the following:
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A template that describes all of the resources that you want in the new stack. Save the template locally or in an Amazon S3 bucket.
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For each resource you want to import, include the following:
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the resource attributes and property values that define the resource's current configuration.
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the unique identifier for the resource, such as the resource name. To obtain unique identifiers, see the appropriate service console.
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Topics
Example template
In this walkthrough, we assume you're using the following example template, called
TemplateToImport.json
, that specifies two DynamoDB tables that were created outside
of CloudFormation. ServiceTable
and GamesTable
are the targets of the
import.
Note
This template is meant as an example only. To use it for your own testing purposes, replace the sample resources with resources from your account.
{ "AWSTemplateFormatVersion": "2010-09-09", "Description": "Import test", "Resources": { "ServiceTable": { "Type": "AWS::DynamoDB::Table", "DeletionPolicy": "Retain", "Properties": { "TableName": "Service", "AttributeDefinitions": [ { "AttributeName": "key", "AttributeType": "S" } ], "KeySchema": [ { "AttributeName": "key", "KeyType": "HASH" } ], "ProvisionedThroughput": { "ReadCapacityUnits": 5, "WriteCapacityUnits": 1 } } }, "GamesTable": { "Type": "AWS::DynamoDB::Table", "DeletionPolicy": "Retain", "Properties": { "TableName": "Games", "AttributeDefinitions": [ { "AttributeName": "key", "AttributeType": "S" } ], "KeySchema": [ { "AttributeName": "key", "KeyType": "HASH" } ], "ProvisionedThroughput": { "ReadCapacityUnits": 5, "WriteCapacityUnits": 1 } } } } }
Create a stack from existing resources using the Amazon Web Services Management Console
Sign in to the Amazon Web Services Management Console and open the Amazon CloudFormation console at https://console.amazonaws.cn/cloudformation
. -
On the Stacks page, choose Create stack, and then choose With existing resources (import resources).
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Read the Import overview page for a list of things you're required to provide during this operation. Then, choose Next.
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On the Specify template page, provide your template using one of the following methods, and then choose Next.
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Choose Amazon S3 URL, and then specify the URL for your template in the text box.
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Choose Upload a template file, and then browse for your template.
-
-
On the Identify resources page, identify each target resource.
-
Under Identifier property, choose the type of resource identifier. For example, the
AWS::DynamoDB::Table
resource can be identified using theTableName
property. -
Under Identifier value, type the actual property value. For example, the
TableName
for theGamesTable
resource in the example template is
.Games
-
Choose Next.
-
-
On the Specify stack details page, modify any parameters, and then choose Next. This automatically creates a change set.
Important
The import operation fails if you modify existing parameters that initiate a create, update, or delete operation.
-
On the Review
stack-name
page, confirm that the correct resources are being imported, and then choose Import resources. This automatically executes the change set created in the last step.The Events pane of the Stack details page for your new stack displays.
-
(Optional) Run drift detection on the stack to make sure the template and actual configuration of the imported resources match. For more information about detecting drift, see Detect drift on an entire CloudFormation stack.
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(Optional) If your imported resources don't match their expected template configurations, either correct the template configurations or update the resources directly. In this walkthrough, we correct the template configurations to match their actual configurations.
-
Revert the import operation for the affected resources.
-
Add the import targets to your template again, making sure that the template configurations match the actual configurations.
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Repeat steps 2 – 8 using the modified template to import the resources again.
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Create a stack from existing resources using the Amazon CLI
-
Open the Amazon CLI.
-
Optionally run
GetTemplateSummary
to learn which properties identify each resource type in your template. For example, theAWS::DynamoDB::Table
resource can be identified using theTableName
property. For theGamesTable
resource in the example template, the value ofTableName
isGames
.>
aws cloudformation get-template-summary --template-url https://
DOC-EXAMPLE-BUCKET
.s3.us-west-2
.amazonaws.com/TemplateToImport.json
-
Compose a list of the target resources from your template and their unique identifiers in the following format.
[{\"ResourceType\":\"
AWS::DynamoDB::Table
\",\"LogicalResourceId\":\"GamesTable
\",\"ResourceIdentifier\":{\"TableName
\":\"Games
\"}}] -
Create a change set of type
IMPORT
with the following parameters.--resources-to-import
doesn't support inline YAML.>
aws cloudformation create-change-set --stack-name
TargetStack
--change-set-nameImportChangeSet
--change-set-typeIMPORT
--resources-to-import "[{\"ResourceType\":\"AWS::DynamoDB::Table
\",\"LogicalResourceId\":\"GamesTable
\",\"ResourceIdentifier\":{\"TableName
\":\"Games
\"}},{\"ResourceType\":\"AWS::DynamoDB::Table
\",\"LogicalResourceId\":\"ServiceTable
\",\"ResourceIdentifier\":{\"TableName
\":\"Service
\"}}]" --template-url https://DOC-EXAMPLE-BUCKET
.s3.us-west-2
.amazonaws.com/TemplateToImport.json
The Amazon CLI also supports text files as input for the
--resources-to-import
parameter, as shown in the following example.--resources-to-import
file://ResourcesToImport.txt
In this walkthrough,
file://ResourcesToImport.txt
contains the following.[ { "ResourceType":"AWS::DynamoDB::Table", "LogicalResourceId":"GamesTable", "ResourceIdentifier":{ "TableName":"Games" } }, { "ResourceType":"AWS::DynamoDB::Table", "LogicalResourceId":"ServiceTable", "ResourceIdentifier":{ "TableName":"Service" } } ]
-
Review the change set to make sure the correct resources will be imported.
>
aws cloudformation describe-change-set --change-set-name
ImportChangeSet
--stack-nameTargetStack
-
Execute the change set to import the resources. On successful completion of the operation
(IMPORT_COMPLETE)
, the resources are successfully imported.>
aws cloudformation execute-change-set --change-set-name
ImportChangeSet
--stack-nameTargetStack
-
(Optional) Run drift detection on the
IMPORT_COMPLETE
stack to make sure the template and actual configuration of the imported resources match. For more information on detecting drift, see Detect drift on individual stack resources.>
aws cloudformation detect-stack-drift --stack-name
TargetStack
{ "StackDriftDetectionId" : "624af370-311a-11e8-b6b7-500cexample" }>
aws cloudformation describe-stack-drift-detection-status --stack-drift-detection-id
624af370-311a-11e8-b6b7-500cexample
>
aws cloudformation describe-stack-resource-drifts --stack-name
TargetStack
-
(Optional) If your imported resources don't match their expected template configurations, either correct the template configurations or update the resources directly. In this walkthrough, we correct the template configurations to match their actual configurations.
-
Revert the import operation for the affected resources.
-
Add the import targets to your template again, making sure that the template configurations match the actual configurations.
-
Repeat steps 4 – 7 using the modified template to import the resources again.
-