AWS CloudFormation

2023/07/28 - AWS CloudFormation - 5 updated api methods

Changes  This SDK release is for the feature launch of AWS CloudFormation RetainExceptOnCreate. It adds a new parameter retainExceptOnCreate in the following APIs: CreateStack, UpdateStack, RollbackStack, ExecuteChangeSet.

CreateStack (updated) Link ¶
Changes (request)
{'RetainExceptOnCreate': 'boolean'}

Creates a stack as specified in the template. After the call completes successfully, the stack creation starts. You can check the status of the stack through the DescribeStacks operation.

See also: AWS API Documentation

Request Syntax

client.create_stack(
    StackName='string',
    TemplateBody='string',
    TemplateURL='string',
    Parameters=[
        {
            'ParameterKey': 'string',
            'ParameterValue': 'string',
            'UsePreviousValue': True|False,
            'ResolvedValue': 'string'
        },
    ],
    DisableRollback=True|False,
    RollbackConfiguration={
        'RollbackTriggers': [
            {
                'Arn': 'string',
                'Type': 'string'
            },
        ],
        'MonitoringTimeInMinutes': 123
    },
    TimeoutInMinutes=123,
    NotificationARNs=[
        'string',
    ],
    Capabilities=[
        'CAPABILITY_IAM'|'CAPABILITY_NAMED_IAM'|'CAPABILITY_AUTO_EXPAND',
    ],
    ResourceTypes=[
        'string',
    ],
    RoleARN='string',
    OnFailure='DO_NOTHING'|'ROLLBACK'|'DELETE',
    StackPolicyBody='string',
    StackPolicyURL='string',
    Tags=[
        {
            'Key': 'string',
            'Value': 'string'
        },
    ],
    ClientRequestToken='string',
    EnableTerminationProtection=True|False,
    RetainExceptOnCreate=True|False
)
type StackName

string

param StackName

[REQUIRED]

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.

type TemplateBody

string

param TemplateBody

Structure containing the template body with a minimum length of 1 byte and a maximum length of 51,200 bytes. For more information, go to Template anatomy in the CloudFormation User Guide.

Conditional: You must specify either the TemplateBody or the TemplateURL parameter, but not both.

type TemplateURL

string

param 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 or a Systems Manager document. For more information, go to the Template anatomy in the CloudFormation User Guide.

Conditional: You must specify either the TemplateBody or the TemplateURL parameter, but not both.

type Parameters

list

param Parameters

A list of Parameter structures that specify input parameters for the stack. For more information, see the Parameter data type.

  • (dict) --

    The Parameter data type.

    • ParameterKey (string) --

      The key associated with the parameter. If you don't specify a key and value for a particular parameter, CloudFormation uses the default value that's specified in your template.

    • ParameterValue (string) --

      The input value associated with the parameter.

    • UsePreviousValue (boolean) --

      During a stack update, use the existing parameter value that the stack is using for a given parameter key. If you specify true , do not specify a parameter value.

    • ResolvedValue (string) --

      Read-only. The value that corresponds to a SSM parameter key. This field is returned only for SSM parameter types in the template.

type DisableRollback

boolean

param DisableRollback

Set to true to disable rollback of the stack if stack creation failed. You can specify either DisableRollback or OnFailure , but not both.

Default: false

type RollbackConfiguration

dict

param RollbackConfiguration

The rollback triggers for CloudFormation to monitor during stack creation and updating operations, and for the specified monitoring period afterwards.

  • RollbackTriggers (list) --

    The triggers to monitor during stack creation or update actions.

    By default, CloudFormation saves the rollback triggers specified for a stack and applies them to any subsequent update operations for the stack, unless you specify otherwise. If you do specify rollback triggers for this parameter, those triggers replace any list of triggers previously specified for the stack. This means:

    • To use the rollback triggers previously specified for this stack, if any, don't specify this parameter.

    • To specify new or updated rollback triggers, you must specify all the triggers that you want used for this stack, even triggers you've specified before (for example, when creating the stack or during a previous stack update). Any triggers that you don't include in the updated list of triggers are no longer applied to the stack.

    • To remove all currently specified triggers, specify an empty list for this parameter.

    If a specified trigger is missing, the entire stack operation fails and is rolled back.

    • (dict) --

      A rollback trigger CloudFormation monitors during creation and updating of stacks. If any of the alarms you specify goes to ALARM state during the stack operation or within the specified monitoring period afterwards, CloudFormation rolls back the entire stack operation.

      • Arn (string) -- [REQUIRED]

        The Amazon Resource Name (ARN) of the rollback trigger.

        If a specified trigger is missing, the entire stack operation fails and is rolled back.

      • Type (string) -- [REQUIRED]

        The resource type of the rollback trigger. Specify either AWS::CloudWatch::Alarm or AWS::CloudWatch::CompositeAlarm resource types.

  • MonitoringTimeInMinutes (integer) --

    The amount of time, in minutes, during which CloudFormation should monitor all the rollback triggers after the stack creation or update operation deploys all necessary resources.

    The default is 0 minutes.

    If you specify a monitoring period but don't specify any rollback triggers, CloudFormation still waits the specified period of time before cleaning up old resources after update operations. You can use this monitoring period to perform any manual stack validation desired, and manually cancel the stack creation or update (using CancelUpdateStack , for example) as necessary.

    If you specify 0 for this parameter, CloudFormation still monitors the specified rollback triggers during stack creation and update operations. Then, for update operations, it begins disposing of old resources immediately once the operation completes.

type TimeoutInMinutes

integer

param TimeoutInMinutes

The amount of time that can pass before the stack status becomes CREATE_FAILED; if DisableRollback is not set or is set to false , the stack will be rolled back.

type NotificationARNs

list

param NotificationARNs

The Amazon Simple Notification Service (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).

  • (string) --

type Capabilities

list

param 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 and CAPABILITY_NAMED_IAM Some stack templates might include resources that can affect permissions in your Amazon Web Services account; for example, by creating new 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 or CAPABILITY_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 .

  • 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.

Warning

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 Using CloudFormation macros to perform custom processing on templates .

  • (string) --

type ResourceTypes

list

param ResourceTypes

The template resource types that you have permissions to work with for this create stack action, such as AWS::EC2::Instance , AWS::EC2::* , or Custom::MyCustomInstance . Use the following syntax to describe template resource types: AWS::* (for all Amazon Web Services resources), Custom::* (for all custom resources), Custom::*logical_ID* `` (for a specific custom resource), ``AWS::*service_name* ::* (for all resources of a particular Amazon Web Services service), and ``AWS::service_name ::resource_logical_ID `` (for a specific Amazon Web Services resource).

If the list of resource types doesn't include a resource that you're creating, the stack creation fails. By default, CloudFormation grants permissions to all resource types. Identity and Access Management (IAM) uses this parameter for CloudFormation-specific condition keys in IAM policies. For more information, see Controlling Access with Identity and Access Management .

  • (string) --

type RoleARN

string

param RoleARN

The Amazon Resource Name (ARN) of an Identity and Access Management (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.

type OnFailure

string

param OnFailure

Determines what action will be taken if stack creation fails. This must be one of: DO_NOTHING , ROLLBACK , or DELETE . You can specify either OnFailure or DisableRollback , but not both.

Default: ROLLBACK

type StackPolicyBody

string

param StackPolicyBody

Structure containing the stack policy body. For more information, go to Prevent Updates to Stack Resources in the CloudFormation User Guide . You can specify either the StackPolicyBody or the StackPolicyURL parameter, but not both.

type StackPolicyURL

string

param 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 the StackPolicyURL parameter, but not both.

type Tags

list

param Tags

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.

  • (dict) --

    The Tag type enables you to specify a key-value pair that can be used to store information about an CloudFormation stack.

    • Key (string) -- [REQUIRED]

      Required . A string used to identify this tag. You can specify a maximum of 128 characters for a tag key. Tags owned by Amazon Web Services (Amazon Web Services) have the reserved prefix: aws: .

    • Value (string) -- [REQUIRED]

      Required . A string containing the value for this tag. You can specify a maximum of 256 characters for a tag value.

type ClientRequestToken

string

param ClientRequestToken

A unique identifier for this CreateStack request. Specify this token if you plan to retry requests so that CloudFormation knows that you're not attempting to create a stack with the same name. You might retry CreateStack requests to ensure that CloudFormation successfully received them.

All events initiated by a given stack operation are assigned the same client request token, which you can use to track operations. For example, if you execute a CreateStack operation with the token token1 , then all the StackEvents generated by that operation will have ClientRequestToken set as token1 .

In the console, stack operations display the client request token on the Events tab. Stack operations that are initiated from the console use the token format Console-StackOperation-ID , which helps you easily identify the stack operation . For example, if you create a stack using the console, each stack event would be assigned the same token in the following format: Console-CreateStack-7f59c3cf-00d2-40c7-b2ff-e75db0987002 .

type EnableTerminationProtection

boolean

param 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 Protecting a Stack From Being Deleted in the 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.

type RetainExceptOnCreate

boolean

param RetainExceptOnCreate

This deletion policy deletes newly created resources, but retains existing resources, when a stack operation is rolled back. This ensures new, empty, and unused resources are deleted, while critical resources and their data are retained. RetainExceptOnCreate can be specified for any resource that supports the DeletionPolicy attribute.

rtype

dict

returns

Response Syntax

{
    'StackId': 'string'
}

Response Structure

  • (dict) --

    The output for a CreateStack action.

    • StackId (string) --

      Unique identifier of the stack.

DescribeStacks (updated) Link ¶
Changes (response)
{'Stacks': {'RetainExceptOnCreate': 'boolean'}}

Returns the description for the specified stack; if no stack name was specified, then it returns the description for all the stacks created.

Note

If the stack doesn't exist, an ValidationError is returned.

See also: AWS API Documentation

Request Syntax

client.describe_stacks(
    StackName='string',
    NextToken='string'
)
type StackName

string

param StackName

Note

If you don't pass a parameter to StackName , the API returns a response that describes all resources in the account. This requires ListStacks and DescribeStacks permissions.

The IAM policy below can be added to IAM policies when you want to limit resource-level permissions and avoid returning a response when no parameter is sent in the request:

{ "Version": "2012-10-17", "Statement": [{ "Effect": "Deny", "Action": "cloudformation:DescribeStacks", "NotResource": "arn:aws:cloudformation:::stack//" }] }

The name or the unique stack ID that's associated with the stack, which aren't always interchangeable:

  • Running stacks: You can specify either the stack's name or its unique stack ID.

  • Deleted stacks: You must specify the unique stack ID.

Default: There is no default value.

type NextToken

string

param NextToken

A string that identifies the next page of stacks that you want to retrieve.

rtype

dict

returns

Response Syntax

{
    'Stacks': [
        {
            'StackId': 'string',
            'StackName': 'string',
            'ChangeSetId': 'string',
            'Description': 'string',
            'Parameters': [
                {
                    'ParameterKey': 'string',
                    'ParameterValue': 'string',
                    'UsePreviousValue': True|False,
                    'ResolvedValue': 'string'
                },
            ],
            'CreationTime': datetime(2015, 1, 1),
            'DeletionTime': datetime(2015, 1, 1),
            'LastUpdatedTime': datetime(2015, 1, 1),
            'RollbackConfiguration': {
                'RollbackTriggers': [
                    {
                        'Arn': 'string',
                        'Type': 'string'
                    },
                ],
                'MonitoringTimeInMinutes': 123
            },
            'StackStatus': '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',
            'StackStatusReason': 'string',
            'DisableRollback': True|False,
            'NotificationARNs': [
                'string',
            ],
            'TimeoutInMinutes': 123,
            'Capabilities': [
                'CAPABILITY_IAM'|'CAPABILITY_NAMED_IAM'|'CAPABILITY_AUTO_EXPAND',
            ],
            'Outputs': [
                {
                    'OutputKey': 'string',
                    'OutputValue': 'string',
                    'Description': 'string',
                    'ExportName': 'string'
                },
            ],
            'RoleARN': 'string',
            'Tags': [
                {
                    'Key': 'string',
                    'Value': 'string'
                },
            ],
            'EnableTerminationProtection': True|False,
            'ParentId': 'string',
            'RootId': 'string',
            'DriftInformation': {
                'StackDriftStatus': 'DRIFTED'|'IN_SYNC'|'UNKNOWN'|'NOT_CHECKED',
                'LastCheckTimestamp': datetime(2015, 1, 1)
            },
            'RetainExceptOnCreate': True|False
        },
    ],
    'NextToken': 'string'
}

Response Structure

  • (dict) --

    The output for a DescribeStacks action.

    • Stacks (list) --

      A list of stack structures.

      • (dict) --

        The Stack data type.

        • StackId (string) --

          Unique identifier of the stack.

        • StackName (string) --

          The name associated with the stack.

        • ChangeSetId (string) --

          The unique ID of the change set.

        • Description (string) --

          A user-defined description associated with the stack.

        • Parameters (list) --

          A list of Parameter structures.

          • (dict) --

            The Parameter data type.

            • ParameterKey (string) --

              The key associated with the parameter. If you don't specify a key and value for a particular parameter, CloudFormation uses the default value that's specified in your template.

            • ParameterValue (string) --

              The input value associated with the parameter.

            • UsePreviousValue (boolean) --

              During a stack update, use the existing parameter value that the stack is using for a given parameter key. If you specify true , do not specify a parameter value.

            • ResolvedValue (string) --

              Read-only. The value that corresponds to a SSM parameter key. This field is returned only for SSM parameter types in the template.

        • CreationTime (datetime) --

          The time at which the stack was created.

        • DeletionTime (datetime) --

          The time the stack was deleted.

        • LastUpdatedTime (datetime) --

          The time the stack was last updated. This field will only be returned if the stack has been updated at least once.

        • RollbackConfiguration (dict) --

          The rollback triggers for CloudFormation to monitor during stack creation and updating operations, and for the specified monitoring period afterwards.

          • RollbackTriggers (list) --

            The triggers to monitor during stack creation or update actions.

            By default, CloudFormation saves the rollback triggers specified for a stack and applies them to any subsequent update operations for the stack, unless you specify otherwise. If you do specify rollback triggers for this parameter, those triggers replace any list of triggers previously specified for the stack. This means:

            • To use the rollback triggers previously specified for this stack, if any, don't specify this parameter.

            • To specify new or updated rollback triggers, you must specify all the triggers that you want used for this stack, even triggers you've specified before (for example, when creating the stack or during a previous stack update). Any triggers that you don't include in the updated list of triggers are no longer applied to the stack.

            • To remove all currently specified triggers, specify an empty list for this parameter.

            If a specified trigger is missing, the entire stack operation fails and is rolled back.

            • (dict) --

              A rollback trigger CloudFormation monitors during creation and updating of stacks. If any of the alarms you specify goes to ALARM state during the stack operation or within the specified monitoring period afterwards, CloudFormation rolls back the entire stack operation.

              • Arn (string) --

                The Amazon Resource Name (ARN) of the rollback trigger.

                If a specified trigger is missing, the entire stack operation fails and is rolled back.

              • Type (string) --

                The resource type of the rollback trigger. Specify either AWS::CloudWatch::Alarm or AWS::CloudWatch::CompositeAlarm resource types.

          • MonitoringTimeInMinutes (integer) --

            The amount of time, in minutes, during which CloudFormation should monitor all the rollback triggers after the stack creation or update operation deploys all necessary resources.

            The default is 0 minutes.

            If you specify a monitoring period but don't specify any rollback triggers, CloudFormation still waits the specified period of time before cleaning up old resources after update operations. You can use this monitoring period to perform any manual stack validation desired, and manually cancel the stack creation or update (using CancelUpdateStack , for example) as necessary.

            If you specify 0 for this parameter, CloudFormation still monitors the specified rollback triggers during stack creation and update operations. Then, for update operations, it begins disposing of old resources immediately once the operation completes.

        • StackStatus (string) --

          Current status of the stack.

        • StackStatusReason (string) --

          Success/failure message associated with the stack status.

        • DisableRollback (boolean) --

          Boolean to enable or disable rollback on stack creation failures:

          • true : disable rollback.

          • false : enable rollback.

        • NotificationARNs (list) --

          Amazon SNS topic Amazon Resource Names (ARNs) to which stack related events are published.

          • (string) --

        • TimeoutInMinutes (integer) --

          The amount of time within which stack creation should complete.

        • Capabilities (list) --

          The capabilities allowed in the stack.

          • (string) --

        • Outputs (list) --

          A list of output structures.

          • (dict) --

            The Output data type.

            • OutputKey (string) --

              The key associated with the output.

            • OutputValue (string) --

              The value associated with the output.

            • Description (string) --

              User defined description associated with the output.

            • ExportName (string) --

              The name of the export associated with the output.

        • RoleARN (string) --

          The Amazon Resource Name (ARN) of an Identity and Access Management (IAM) role that's associated with the stack. During a stack operation, CloudFormation uses this role's credentials to make calls on your behalf.

        • Tags (list) --

          A list of Tag s that specify information about the stack.

          • (dict) --

            The Tag type enables you to specify a key-value pair that can be used to store information about an CloudFormation stack.

            • Key (string) --

              Required . A string used to identify this tag. You can specify a maximum of 128 characters for a tag key. Tags owned by Amazon Web Services (Amazon Web Services) have the reserved prefix: aws: .

            • Value (string) --

              Required . A string containing the value for this tag. You can specify a maximum of 256 characters for a tag value.

        • EnableTerminationProtection (boolean) --

          Whether termination protection is enabled for the stack.

          For nested stacks , termination protection is set on the root stack and can't be changed directly on the nested stack. For more information, see Protecting a Stack From Being Deleted in the CloudFormation User Guide .

        • ParentId (string) --

          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 Working with Nested Stacks in the CloudFormation User Guide .

        • RootId (string) --

          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 Working with Nested Stacks in the CloudFormation User Guide .

        • DriftInformation (dict) --

          Information about whether a stack's actual configuration differs, or has drifted , from its expected configuration, as defined in the stack template and any values specified as template parameters. For more information, see Detecting Unregulated Configuration Changes to Stacks and Resources .

          • StackDriftStatus (string) --

            Status of the stack's actual configuration compared to its expected template configuration.

            • DRIFTED : The stack differs from its expected template configuration. A stack is considered to have drifted if one or more of its resources have drifted.

            • NOT_CHECKED : CloudFormation hasn't checked if the stack differs from its expected template configuration.

            • IN_SYNC : The stack's actual configuration matches its expected template configuration.

            • UNKNOWN : This value is reserved for future use.

          • LastCheckTimestamp (datetime) --

            Most recent time when a drift detection operation was initiated on the stack, or any of its individual resources that support drift detection.

        • RetainExceptOnCreate (boolean) --

          This deletion policy deletes newly created resources, but retains existing resources, when a stack operation is rolled back. This ensures new, empty, and unused resources are deleted, while critical resources and their data are retained. RetainExceptOnCreate can be specified for any resource that supports the DeletionPolicy attribute.

    • NextToken (string) --

      If the output exceeds 1 MB in size, a string that identifies the next page of stacks. If no additional page exists, this value is null.

ExecuteChangeSet (updated) Link ¶
Changes (request)
{'RetainExceptOnCreate': 'boolean'}

Updates a stack using the input information that was provided when the specified change set was created. After the call successfully completes, CloudFormation starts updating the stack. Use the DescribeStacks action to view the status of the update.

When you execute a change set, CloudFormation deletes all other change sets associated with the stack because they aren't valid for the updated stack.

If a stack policy is associated with the stack, CloudFormation enforces the policy during the update. You can't specify a temporary stack policy that overrides the current policy.

To create a change set for the entire stack hierarchy, IncludeNestedStacks must have been set to True .

See also: AWS API Documentation

Request Syntax

client.execute_change_set(
    ChangeSetName='string',
    StackName='string',
    ClientRequestToken='string',
    DisableRollback=True|False,
    RetainExceptOnCreate=True|False
)
type ChangeSetName

string

param ChangeSetName

[REQUIRED]

The name or Amazon Resource Name (ARN) of the change set that you want use to update the specified stack.

type StackName

string

param StackName

If you specified the name of a change set, specify the stack name or Amazon Resource Name (ARN) that's associated with the change set you want to execute.

type ClientRequestToken

string

param ClientRequestToken

A unique identifier for this ExecuteChangeSet request. Specify this token if you plan to retry requests so that CloudFormation knows that you're not attempting to execute a change set to update a stack with the same name. You might retry ExecuteChangeSet requests to ensure that CloudFormation successfully received them.

type DisableRollback

boolean

param DisableRollback

Preserves the state of previously provisioned resources when an operation fails. This parameter can't be specified when the OnStackFailure parameter to the CreateChangeSet API operation was specified.

  • True - if the stack creation fails, do nothing. This is equivalent to specifying DO_NOTHING for the OnStackFailure parameter to the CreateChangeSet API operation.

  • False - if the stack creation fails, roll back the stack. This is equivalent to specifying ROLLBACK for the OnStackFailure parameter to the CreateChangeSet API operation.

Default: True

type RetainExceptOnCreate

boolean

param RetainExceptOnCreate

This deletion policy deletes newly created resources, but retains existing resources, when a stack operation is rolled back. This ensures new, empty, and unused resources are deleted, while critical resources and their data are retained. RetainExceptOnCreate can be specified for any resource that supports the DeletionPolicy attribute.

rtype

dict

returns

Response Syntax

{}

Response Structure

  • (dict) --

    The output for the ExecuteChangeSet action.

RollbackStack (updated) Link ¶
Changes (request)
{'RetainExceptOnCreate': 'boolean'}

When specifying RollbackStack , you preserve the state of previously provisioned resources when an operation fails. You can check the status of the stack through the DescribeStacks operation.

Rolls back the specified stack to the last known stable state from CREATE_FAILED or UPDATE_FAILED stack statuses.

This operation will delete a stack if it doesn't contain a last known stable state. A last known stable state includes any status in a *_COMPLETE . This includes the following stack statuses.

  • CREATE_COMPLETE

  • UPDATE_COMPLETE

  • UPDATE_ROLLBACK_COMPLETE

  • IMPORT_COMPLETE

  • IMPORT_ROLLBACK_COMPLETE

See also: AWS API Documentation

Request Syntax

client.rollback_stack(
    StackName='string',
    RoleARN='string',
    ClientRequestToken='string',
    RetainExceptOnCreate=True|False
)
type StackName

string

param StackName

[REQUIRED]

The name that's associated with the stack.

type RoleARN

string

param RoleARN

The Amazon Resource Name (ARN) of an Identity and Access Management role that CloudFormation assumes to rollback the stack.

type ClientRequestToken

string

param ClientRequestToken

A unique identifier for this RollbackStack request.

type RetainExceptOnCreate

boolean

param RetainExceptOnCreate

This deletion policy deletes newly created resources, but retains existing resources, when a stack operation is rolled back. This ensures new, empty, and unused resources are deleted, while critical resources and their data are retained. RetainExceptOnCreate can be specified for any resource that supports the DeletionPolicy attribute.

rtype

dict

returns

Response Syntax

{
    'StackId': 'string'
}

Response Structure

  • (dict) --

    • StackId (string) --

      Unique identifier of the stack.

UpdateStack (updated) Link ¶
Changes (request)
{'RetainExceptOnCreate': 'boolean'}

Updates a stack as specified in the template. After the call completes successfully, the stack update starts. You can check the status of the stack through the DescribeStacks action.

To get a copy of the template for an existing stack, you can use the GetTemplate action.

For more information about creating an update template, updating a stack, and monitoring the progress of the update, see Updating a Stack .

See also: AWS API Documentation

Request Syntax

client.update_stack(
    StackName='string',
    TemplateBody='string',
    TemplateURL='string',
    UsePreviousTemplate=True|False,
    StackPolicyDuringUpdateBody='string',
    StackPolicyDuringUpdateURL='string',
    Parameters=[
        {
            'ParameterKey': 'string',
            'ParameterValue': 'string',
            'UsePreviousValue': True|False,
            'ResolvedValue': 'string'
        },
    ],
    Capabilities=[
        'CAPABILITY_IAM'|'CAPABILITY_NAMED_IAM'|'CAPABILITY_AUTO_EXPAND',
    ],
    ResourceTypes=[
        'string',
    ],
    RoleARN='string',
    RollbackConfiguration={
        'RollbackTriggers': [
            {
                'Arn': 'string',
                'Type': 'string'
            },
        ],
        'MonitoringTimeInMinutes': 123
    },
    StackPolicyBody='string',
    StackPolicyURL='string',
    NotificationARNs=[
        'string',
    ],
    Tags=[
        {
            'Key': 'string',
            'Value': 'string'
        },
    ],
    DisableRollback=True|False,
    ClientRequestToken='string',
    RetainExceptOnCreate=True|False
)
type StackName

string

param StackName

[REQUIRED]

The name or unique stack ID of the stack to update.

type TemplateBody

string

param TemplateBody

Structure containing the template body with a minimum length of 1 byte and a maximum length of 51,200 bytes. (For more information, go to Template Anatomy in the CloudFormation User Guide.)

Conditional: You must specify only one of the following parameters: TemplateBody , TemplateURL , or set the UsePreviousTemplate to true .

type TemplateURL

string

param TemplateURL

Location of file containing the template body. The URL must point to a template that's located in an Amazon S3 bucket or a Systems Manager document. For more information, go to Template Anatomy in the CloudFormation User Guide.

Conditional: You must specify only one of the following parameters: TemplateBody , TemplateURL , or set the UsePreviousTemplate to true .

type UsePreviousTemplate

boolean

param UsePreviousTemplate

Reuse the existing template that is associated with the stack that you are updating.

Conditional: You must specify only one of the following parameters: TemplateBody , TemplateURL , or set the UsePreviousTemplate to true .

type StackPolicyDuringUpdateBody

string

param StackPolicyDuringUpdateBody

Structure containing the temporary overriding stack policy body. You can specify either the StackPolicyDuringUpdateBody or the StackPolicyDuringUpdateURL parameter, but not both.

If you want to update protected resources, specify a temporary overriding stack policy during this update. If you don't specify a stack policy, the current policy that is associated with the stack will be used.

type StackPolicyDuringUpdateURL

string

param StackPolicyDuringUpdateURL

Location of a file containing the temporary overriding stack policy. The URL must point to a policy (max size: 16KB) located in an S3 bucket in the same Region as the stack. You can specify either the StackPolicyDuringUpdateBody or the StackPolicyDuringUpdateURL parameter, but not both.

If you want to update protected resources, specify a temporary overriding stack policy during this update. If you don't specify a stack policy, the current policy that is associated with the stack will be used.

type Parameters

list

param Parameters

A list of Parameter structures that specify input parameters for the stack. For more information, see the Parameter data type.

  • (dict) --

    The Parameter data type.

    • ParameterKey (string) --

      The key associated with the parameter. If you don't specify a key and value for a particular parameter, CloudFormation uses the default value that's specified in your template.

    • ParameterValue (string) --

      The input value associated with the parameter.

    • UsePreviousValue (boolean) --

      During a stack update, use the existing parameter value that the stack is using for a given parameter key. If you specify true , do not specify a parameter value.

    • ResolvedValue (string) --

      Read-only. The value that corresponds to a SSM parameter key. This field is returned only for SSM parameter types in the template.

type Capabilities

list

param Capabilities

In some cases, you must explicitly acknowledge that your stack template contains certain capabilities in order for CloudFormation to update the stack.

  • CAPABILITY_IAM and CAPABILITY_NAMED_IAM Some stack templates might include resources that can affect permissions in your Amazon Web Services account; for example, by creating new 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 or CAPABILITY_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 suggest that you review all permissions associated with them and edit their permissions if necessary.

For more information, see Acknowledging IAM Resources in CloudFormation Templates .

  • 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 updating the stack. If your stack template contains one or more macros, and you choose to update 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 update a stack from a stack template that contains macros and nested stacks, you must update the stack directly from the template using this capability.

Warning

You should only update 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 Using CloudFormation Macros to Perform Custom Processing on Templates .

  • (string) --

type ResourceTypes

list

param ResourceTypes

The template resource types that you have permissions to work with for this update stack action, such as AWS::EC2::Instance , AWS::EC2::* , or Custom::MyCustomInstance .

If the list of resource types doesn't include a resource that you're updating, the stack update fails. By default, CloudFormation grants permissions to all resource types. Identity and Access Management (IAM) uses this parameter for CloudFormation-specific condition keys in IAM policies. For more information, see Controlling Access with Identity and Access Management .

  • (string) --

type RoleARN

string

param RoleARN

The Amazon Resource Name (ARN) of an Identity and Access Management (IAM) role that CloudFormation assumes to update 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 is generated from your user credentials.

type RollbackConfiguration

dict

param RollbackConfiguration

The rollback triggers for CloudFormation to monitor during stack creation and updating operations, and for the specified monitoring period afterwards.

  • RollbackTriggers (list) --

    The triggers to monitor during stack creation or update actions.

    By default, CloudFormation saves the rollback triggers specified for a stack and applies them to any subsequent update operations for the stack, unless you specify otherwise. If you do specify rollback triggers for this parameter, those triggers replace any list of triggers previously specified for the stack. This means:

    • To use the rollback triggers previously specified for this stack, if any, don't specify this parameter.

    • To specify new or updated rollback triggers, you must specify all the triggers that you want used for this stack, even triggers you've specified before (for example, when creating the stack or during a previous stack update). Any triggers that you don't include in the updated list of triggers are no longer applied to the stack.

    • To remove all currently specified triggers, specify an empty list for this parameter.

    If a specified trigger is missing, the entire stack operation fails and is rolled back.

    • (dict) --

      A rollback trigger CloudFormation monitors during creation and updating of stacks. If any of the alarms you specify goes to ALARM state during the stack operation or within the specified monitoring period afterwards, CloudFormation rolls back the entire stack operation.

      • Arn (string) -- [REQUIRED]

        The Amazon Resource Name (ARN) of the rollback trigger.

        If a specified trigger is missing, the entire stack operation fails and is rolled back.

      • Type (string) -- [REQUIRED]

        The resource type of the rollback trigger. Specify either AWS::CloudWatch::Alarm or AWS::CloudWatch::CompositeAlarm resource types.

  • MonitoringTimeInMinutes (integer) --

    The amount of time, in minutes, during which CloudFormation should monitor all the rollback triggers after the stack creation or update operation deploys all necessary resources.

    The default is 0 minutes.

    If you specify a monitoring period but don't specify any rollback triggers, CloudFormation still waits the specified period of time before cleaning up old resources after update operations. You can use this monitoring period to perform any manual stack validation desired, and manually cancel the stack creation or update (using CancelUpdateStack , for example) as necessary.

    If you specify 0 for this parameter, CloudFormation still monitors the specified rollback triggers during stack creation and update operations. Then, for update operations, it begins disposing of old resources immediately once the operation completes.

type StackPolicyBody

string

param StackPolicyBody

Structure containing a new stack policy body. You can specify either the StackPolicyBody or the StackPolicyURL parameter, but not both.

You might update the stack policy, for example, in order to protect a new resource that you created during a stack update. If you don't specify a stack policy, the current policy that is associated with the stack is unchanged.

type StackPolicyURL

string

param StackPolicyURL

Location of a file containing the updated stack policy. The URL must point to a policy (max size: 16KB) located in an S3 bucket in the same Region as the stack. You can specify either the StackPolicyBody or the StackPolicyURL parameter, but not both.

You might update the stack policy, for example, in order to protect a new resource that you created during a stack update. If you don't specify a stack policy, the current policy that is associated with the stack is unchanged.

type NotificationARNs

list

param NotificationARNs

Amazon Simple Notification Service topic Amazon Resource Names (ARNs) that CloudFormation associates with the stack. Specify an empty list to remove all notification topics.

  • (string) --

type Tags

list

param Tags

Key-value pairs to associate with this stack. CloudFormation also propagates these tags to supported resources in the stack. You can specify a maximum number of 50 tags.

If you don't specify this parameter, CloudFormation doesn't modify the stack's tags. If you specify an empty value, CloudFormation removes all associated tags.

  • (dict) --

    The Tag type enables you to specify a key-value pair that can be used to store information about an CloudFormation stack.

    • Key (string) -- [REQUIRED]

      Required . A string used to identify this tag. You can specify a maximum of 128 characters for a tag key. Tags owned by Amazon Web Services (Amazon Web Services) have the reserved prefix: aws: .

    • Value (string) -- [REQUIRED]

      Required . A string containing the value for this tag. You can specify a maximum of 256 characters for a tag value.

type DisableRollback

boolean

param DisableRollback

Preserve the state of previously provisioned resources when an operation fails.

Default: False

type ClientRequestToken

string

param ClientRequestToken

A unique identifier for this UpdateStack request. Specify this token if you plan to retry requests so that CloudFormation knows that you're not attempting to update a stack with the same name. You might retry UpdateStack requests to ensure that CloudFormation successfully received them.

All events triggered by a given stack operation are assigned the same client request token, which you can use to track operations. For example, if you execute a CreateStack operation with the token token1 , then all the StackEvents generated by that operation will have ClientRequestToken set as token1 .

In the console, stack operations display the client request token on the Events tab. Stack operations that are initiated from the console use the token format Console-StackOperation-ID , which helps you easily identify the stack operation . For example, if you create a stack using the console, each stack event would be assigned the same token in the following format: Console-CreateStack-7f59c3cf-00d2-40c7-b2ff-e75db0987002 .

type RetainExceptOnCreate

boolean

param RetainExceptOnCreate

This deletion policy deletes newly created resources, but retains existing resources, when a stack operation is rolled back. This ensures new, empty, and unused resources are deleted, while critical resources and their data are retained. RetainExceptOnCreate can be specified for any resource that supports the DeletionPolicy attribute.

rtype

dict

returns

Response Syntax

{
    'StackId': 'string'
}

Response Structure

  • (dict) --

    The output for an UpdateStack action.

    • StackId (string) --

      Unique identifier of the stack.