AWS::CloudFormation::Stack
The AWS::CloudFormation::Stack
resource nests a stack as a resource in a
top-level template.
For more information, see Embed stacks within other stacks using nested stacks in the Amazon CloudFormation User Guide.
You can add output values from a nested stack within the containing template. You use
the GetAtt function with the nested stack's logical name and the name of the output
value in the nested stack in the format
Outputs.NestedStackOutputName
.
We strongly recommend that updates to nested stacks are run from the parent stack.
When you apply template changes to update a top-level stack, CloudFormation updates the top-level stack and initiates an update to its nested stacks. CloudFormation updates the resources of modified nested stacks, but doesn't update the resources of unmodified nested stacks.
You must acknowledge IAM capabilities for nested stacks that contain IAM resources. Also, verify that you have cancel update stack permissions, which is required if an update rolls back. For more information about IAM and CloudFormation, see Controlling access with Amazon Identity and Access Management in the Amazon CloudFormation User Guide.
Note
A subset of AWS::CloudFormation::Stack
resource type properties listed
below are available to customers using CloudFormation, Amazon CDK, and
Amazon Cloud Control API to configure.
-
NotificationARNs
-
Parameters
-
Tags
-
TemplateURL
-
TimeoutInMinutes
These properties can be configured only when using Amazon Cloud Control API. This is because the below properties are set by the parent stack, and thus cannot be configured using CloudFormation or Amazon CDK but only Amazon Cloud Control API.
-
Capabilities
-
Description
-
DisableRollback
-
EnableTerminationProtection
-
RoleARN
-
StackName
-
StackPolicyBody
-
StackPolicyURL
-
StackStatusReason
-
TemplateBody
Customers that configure AWS::CloudFormation::Stack
using CloudFormation and Amazon CDK can do so for nesting a CloudFormation stack as a resource in their top-level template.
These read-only properties can be accessed only when using Amazon Cloud Control API.
-
ChangeSetId
-
CreationTime
-
LastUpdateTime
-
Outputs
-
ParentId
-
RootId
-
StackId
-
StackStatus
Syntax
To declare this entity in your Amazon CloudFormation template, use the following syntax:
JSON
{ "Type" : "AWS::CloudFormation::Stack", "Properties" : { "Capabilities" :
[ String, ... ]
, "ChangeSetId" :String
, "CreationTime" :String
, "Description" :String
, "DisableRollback" :Boolean
, "EnableTerminationProtection" :Boolean
, "LastUpdateTime" :String
, "NotificationARNs" :[ String, ... ]
, "Outputs" :[ Output, ... ]
, "Parameters" :{
, "ParentId" :Key
:Value
, ...}String
, "RoleARN" :String
, "RootId" :String
, "StackId" :String
, "StackName" :String
, "StackPolicyBody" :Json
, "StackPolicyURL" :String
, "StackStatus" :String
, "StackStatusReason" :String
, "Tags" :[ Tag, ... ]
, "TemplateBody" :Json
, "TemplateURL" :String
, "TimeoutInMinutes" :Integer
} }
YAML
Type: AWS::CloudFormation::Stack Properties: Capabilities:
- String
ChangeSetId:String
CreationTime:String
Description:String
DisableRollback:Boolean
EnableTerminationProtection:Boolean
LastUpdateTime:String
NotificationARNs:- String
Outputs:- Output
Parameters:ParentId:
Key
:Value
String
RoleARN:String
RootId:String
StackId:String
StackName:String
StackPolicyBody:Json
StackPolicyURL:String
StackStatus:String
StackStatusReason:String
Tags:- Tag
TemplateBody:Json
TemplateURL:String
TimeoutInMinutes:Integer
Properties
Capabilities
-
In some cases, you must explicitly acknowledge that your stack template contains certain capabilities in order for CloudFormation to create the stack.
-
CAPABILITY_IAM
andCAPABILITY_NAMED_IAM
Some stack templates might include resources that can affect permissions in your Amazon Web Services account; for example, by creating new Amazon Identity and Access Management (IAM) users. For those stacks, you must explicitly acknowledge this by specifying one of these capabilities.
The following IAM resources require you to specify either the
CAPABILITY_IAM
orCAPABILITY_NAMED_IAM
capability.-
If you have IAM resources, you can specify either capability.
-
If you have IAM resources with custom names, you must specify
CAPABILITY_NAMED_IAM
. -
If you don't specify either of these capabilities, CloudFormation returns an
InsufficientCapabilities
error.
If your stack template contains these resources, we recommend that you review all permissions associated with them and edit their permissions if necessary.
For more information, see Acknowledging IAM resources in CloudFormation templates in the Amazon CloudFormation User Guide.
-
-
CAPABILITY_AUTO_EXPAND
Some template contain macros. Macros perform custom processing on templates; this can include simple actions like find-and-replace operations, all the way to extensive transformations of entire templates. Because of this, users typically create a change set from the processed template, so that they can review the changes resulting from the macros before actually creating the stack. If your stack template contains one or more macros, and you choose to create a stack directly from the processed template, without first reviewing the resulting changes in a change set, you must acknowledge this capability. This includes the AWS::Include and AWS::Serverless transforms, which are macros hosted by CloudFormation.
If you want to create a stack from a stack template that contains macros and nested stacks, you must create the stack directly from the template using this capability.
Important
You should only create stacks directly from a stack template that contains macros if you know what processing the macro performs.
Each macro relies on an underlying Lambda service function for processing stack templates. Be aware that the Lambda function owner can update the function operation without CloudFormation being notified.
For more information, see Perform custom processing on CloudFormation templates with template macros in the Amazon CloudFormation User Guide.
Required: No
Type: Array of String
Allowed values:
CAPABILITY_IAM | CAPABILITY_NAMED_IAM | CAPABILITY_AUTO_EXPAND
Update requires: No interruption
-
ChangeSetId
-
The unique ID of the change set.
Required: No
Type: String
Pattern:
arn:[-a-zA-Z0-9:/]*
Minimum:
1
Update requires: Replacement
CreationTime
-
The time at which the stack was created.
Required: No
Type: String
Update requires: Replacement
Description
-
A user-defined description associated with the stack.
Required: No
Type: String
Minimum:
1
Maximum:
1024
Update requires: No interruption
DisableRollback
-
Set to
true
to disable rollback of the stack if stack creation failed. You can specify eitherDisableRollback
orOnFailure
, but not both.Default:
false
Required: No
Type: Boolean
Update requires: No interruption
EnableTerminationProtection
-
Whether to enable termination protection on the specified stack. If a user attempts to delete a stack with termination protection enabled, the operation fails and the stack remains unchanged. For more information, see Protect CloudFormation stacks from being deleted in the Amazon CloudFormation User Guide. Termination protection is deactivated on stacks by default.
For nested stacks, termination protection is set on the root stack and can't be changed directly on the nested stack.
Required: No
Type: Boolean
Update requires: No interruption
LastUpdateTime
-
The time the stack was last updated. This field will only be returned if the stack has been updated at least once.
Required: No
Type: String
Update requires: Replacement
NotificationARNs
-
The Amazon SNS topic ARNs to publish stack related events. You can find your Amazon SNS topic ARNs using the Amazon SNS console or your Command Line Interface (CLI).
Required: No
Type: Array of String
Maximum:
5
Update requires: No interruption
Outputs
-
A list of output structures.
Required: No
Type: Array of Output
Update requires: Replacement
Parameters
-
The set value pairs that represent the parameters passed to CloudFormation when this nested stack is created. Each parameter has a name corresponding to a parameter defined in the embedded template and a value representing the value that you want to set for the parameter.
Note
If you use the
Ref
function to pass a parameter value to a nested stack, comma-delimited list parameters must be of typeString
. In other words, you can't pass values that are of typeCommaDelimitedList
to nested stacks.Conditional. Required if the nested stack requires input parameters.
Whether an update causes interruptions depends on the resources that are being updated. An update never causes a nested stack to be replaced.
Required: Conditional
Type: Object of String
Pattern:
[a-zA-Z0-9]+
Update requires: No interruption
ParentId
-
For nested stacks--stacks created as resources for another stack--the stack ID of the direct parent of this stack. For the first level of nested stacks, the root stack is also the parent stack.
For more information, see Embed stacks within other stacks using nested stacks in the Amazon CloudFormation User Guide.
Required: No
Type: String
Update requires: Replacement
RoleARN
-
The Amazon Resource Name (ARN) of an IAM role that CloudFormation assumes to create the stack. CloudFormation uses the role's credentials to make calls on your behalf. CloudFormation always uses this role for all future operations on the stack. Provided that users have permission to operate on the stack, CloudFormation uses this role even if the users don't have permission to pass it. Ensure that the role grants least privilege.
If you don't specify a value, CloudFormation uses the role that was previously associated with the stack. If no role is available, CloudFormation uses a temporary session that's generated from your user credentials.
Required: No
Type: String
Minimum:
20
Maximum:
2048
Update requires: No interruption
RootId
-
For nested stacks--stacks created as resources for another stack--the stack ID of the top-level stack to which the nested stack ultimately belongs.
For more information, see Embed stacks within other stacks using nested stacks in the Amazon CloudFormation User Guide.
Required: No
Type: String
Update requires: Replacement
StackId
-
Unique identifier of the stack.
Required: No
Type: String
Update requires: Replacement
StackName
-
The name that's associated with the stack. The name must be unique in the Region in which you are creating the stack.
Note
A stack name can contain only alphanumeric characters (case sensitive) and hyphens. It must start with an alphabetical character and can't be longer than 128 characters.
Required: Yes
Type: String
Update requires: Replacement
StackPolicyBody
-
Structure containing the stack policy body. For more information, go to Prevent updates to stack resources in the Amazon CloudFormation User Guide. You can specify either the
StackPolicyBody
or theStackPolicyURL
parameter, but not both.Required: No
Type: Json
Minimum:
1
Maximum:
16384
Update requires: No interruption
StackPolicyURL
-
Location of a file containing the stack policy. The URL must point to a policy (maximum size: 16 KB) located in an S3 bucket in the same Region as the stack. You can specify either the
StackPolicyBody
or theStackPolicyURL
parameter, but not both.Required: No
Type: String
Minimum:
1
Maximum:
1350
Update requires: No interruption
StackStatus
-
Current status of the stack.
Required: No
Type: String
Allowed values:
CREATE_IN_PROGRESS | CREATE_FAILED | CREATE_COMPLETE | ROLLBACK_IN_PROGRESS | ROLLBACK_FAILED | ROLLBACK_COMPLETE | DELETE_IN_PROGRESS | DELETE_FAILED | DELETE_COMPLETE | UPDATE_IN_PROGRESS | UPDATE_COMPLETE_CLEANUP_IN_PROGRESS | UPDATE_COMPLETE | UPDATE_FAILED | UPDATE_ROLLBACK_IN_PROGRESS | UPDATE_ROLLBACK_FAILED | UPDATE_ROLLBACK_COMPLETE_CLEANUP_IN_PROGRESS | UPDATE_ROLLBACK_COMPLETE | REVIEW_IN_PROGRESS | IMPORT_IN_PROGRESS | IMPORT_COMPLETE | IMPORT_ROLLBACK_IN_PROGRESS | IMPORT_ROLLBACK_FAILED | IMPORT_ROLLBACK_COMPLETE
Update requires: Replacement
StackStatusReason
-
Success/failure message associated with the stack status.
Required: No
Type: String
Update requires: No interruption
-
Key-value pairs to associate with this stack. CloudFormation also propagates these tags to the resources created in the stack. A maximum number of 50 tags can be specified.
Required: No
Type: Array of Tag
Maximum:
50
Update requires: No interruption
TemplateBody
-
Structure containing the template body with a minimum length of 1 byte and a maximum length of 51,200 bytes.
Conditional: You must specify either the
TemplateBody
or theTemplateURL
parameter, but not both.Required: No
Type: Json
Minimum:
1
Update requires: No interruption
TemplateURL
-
Location of file containing the template body. The URL must point to a template (max size: 460,800 bytes) that's located in an Amazon S3 bucket.
Whether an update causes interruptions depends on the resources that are being updated. An update never causes a nested stack to be replaced.
Required: No
Type: String
Minimum:
1
Maximum:
1024
Update requires: No interruption
TimeoutInMinutes
-
The length of time, in minutes, that CloudFormation waits for the nested stack to reach the
CREATE_COMPLETE
state. The default is no timeout. When CloudFormation detects that the nested stack has reached theCREATE_COMPLETE
state, it marks the nested stack resource asCREATE_COMPLETE
in the parent stack and resumes creating the parent stack. If the timeout period expires before the nested stack reachesCREATE_COMPLETE
, CloudFormation marks the nested stack as failed and rolls back both the nested stack and parent stack.Updates aren't supported.
Required: No
Type: Integer
Minimum:
1
Update requires: No interruption
Return values
Ref
When you pass the logical ID of this resource to the intrinsic Ref
function, Ref
returns the stack ID. For example:
arn:aws:cloudformation:us-east-2:123456789012:stack/mystack-mynestedstack-sggfrhxhum7w/f449b250-b969-11e0-a185-5081d0136786
For more information about using the Ref
function, see Ref
.
Fn::GetAtt
The Fn::GetAtt
intrinsic function returns a value for a specified attribute of this type. The following are the available attributes and sample return values.
For more information about using the Fn::GetAtt
intrinsic function, see Fn::GetAtt
.
ChangeSetId
-
Returns the unique ID of the change set.
CreationTime
-
Returns The time at which the stack was created.
LastUpdateTime
-
Returns the time the stack was last updated. This will only be returned if the stack has been updated at least once.
Outputs
-
Returns a list of output structures.
ParentId
-
For nested stacks--stacks created as resources for another stack--returns the stack ID of the direct parent of this stack. For the first level of nested stacks, the root stack is also the parent stack.
RootId
-
For nested stacks--stacks created as resources for another stack--returns the stack ID of the top-level stack to which the nested stack ultimately belongs.
StackId
-
Returns the unique identifier of the stack.
StackStatus
-
Returns a success or failure message associated with the stack status.
Examples
Specify stack parameters
The sample template EC2ChooseAMI.template contains the following Parameters section:
JSON
{ "Parameters": { "InstanceType": { "Type": "String", "Default": "m1.small", "Description": "EC2 instance type, e.g. m1.small, m1.large, etc." }, "WebServerPort": { "Type": "String", "Default": "80", "Description": "TCP/IP port of the web server" }, "KeyName": { "Type": "String", "Description": "Name of an existing EC2 KeyPair to enable SSH access to the web server" } } }
YAML
Parameters: InstanceType: Type: String Default: m1.small Description: 'EC2 instance type, e.g. m1.small, m1.large, etc.' WebServerPort: Type: String Default: '80' Description: TCP/IP port of the web server KeyName: Type: String Description: Name of an existing EC2 KeyPair to enable SSH access to the web server
Nested stack
You could use the following template to embed a stack (myStackWithParams) using
the EC2ChooseAMI.template and use the Parameters property in the
AWS::CloudFormation::Stack
resource to specify an
InstanceType
and KeyName
.
JSON
{ "AWSTemplateFormatVersion" : "2010-09-09", "Resources" : { "myStackWithParams" : { "Type" : "AWS::CloudFormation::Stack", "Properties" : { "TemplateURL" : "https://s3.amazonaws.com/cloudformation-templates-us-east-2/EC2ChooseAMI.template", "Parameters" : { "InstanceType" : "t1.micro", "KeyName" : "mykey" } } } } }
YAML
AWSTemplateFormatVersion: '2010-09-09' Resources: myStackWithParams: Type: AWS::CloudFormation::Stack Properties: TemplateURL: https://s3.amazonaws.com/cloudformation-templates-us-east-2/EC2ChooseAMI.template Parameters: InstanceType: t1.micro KeyName: mykey
See also
-
For sample template snippets, see Nested Stacks in CloudFormation template snippets in the Amazon CloudFormation User Guide.
-
If you have nested stacks that are stuck in an in-progress operation, see Troubleshooting Errors in Troubleshooting Amazon CloudFormation in the Amazon CloudFormation User Guide.