Data structures

Change sets contain JSON changes that describe how ROS modifies a stack. Use change sets to preview the impact before applying changes.

Elements in JSON changes

A change set's JSON changes consist of the following elements, detailed in the data structures section below.

Change: the change operation, including the change type and target entity.
ResourceChange: the resource to change, including resource name, type, and operation.
ResourceChangeDetail: resource change details, including properties and resource status before and after the change.
ResourceTargetDefinition: the target resource definition, including properties and configurations.
ResourcePropertyChange: property-level change details, including values before and after the change.
ModuleInfo: module information for resources created from modules.

Data structures of JSON changes

Change

Parameter

Type

Description

ResourceChange

Structure

The resource to change and the operation to perform.

Type

String

The entity type.

Set to Resource, which indicates the entity is a resource.

ResourceChange

Parameter	Type	Description
Action	String	The operation to perform on the resource. Valid values: `Add`: creates the resource. `Modify`: modifies the resource. `Remove`: releases the resource.
Details	Array	The change details. Takes effect only when `Action` is set to `Modify`. Note Available only for ROS-type stacks.
LogicalResourceId	String	The logical ID of the resource, which is the resource name defined in the template.
PhysicalResourceId	String	The physical ID of the resource. Takes effect only when `Action` is set to `Modify` or `Remove`.
Replacement	String	Whether ROS replaces the resource by creating a new one and deleting the existing one. Takes effect only when `Action` is set to `Modify`. Valid values for stacks of the ROS type: `True`: ROS replaces the resource. Required when `RequiresRecreation` is `Always` and `Evaluation` is `Static`. `False`: ROS does not replace the resource. Required when RequiresRecreation is Never and Evaluation is Static. `Conditional`: ROS may replace the resource. Required when `RequiresRecreation` is `Always` and `Evaluation` is `Dynamic`. Note When multiple `RequiresRecreation` values apply, `Replacement` is determined by the highest-impact value. Impact order: `Always` > `Conditional` > `Never`. Valid values for stacks of the Terraform type: `True`: Terraform replaces the resource. `False`: Terraform does not replace the resource.
ResourceType	String	The resource type.
Scope	Array of strings	The attribute that triggers an update. Takes effect only when `Action` is set to `Modify`. Valid values: `Properties`: the Properties parameter of the resource `Metadata`: the Metadata parameter of the resource `DeletionPolicy`: the DeletionPolicy parameter of the resource Note Available only for ROS-type stacks.
PropertyChanges	Structure array of ResourcePropertyChange	Property-level changes. Takes effect only when `Action` is set to `Modify`. ResourcePropertyChange. Note Available only for Terraform-type stacks.
ModuleInfo	Structure array of ModuleInfo	Module information for the resource. Returned only if the resource is created from modules. ModuleInfo. Note Available only for ROS-type stacks.

ResourceChangeDetail

Parameter	Type	Description
ChangeSource	String	The update trigger. Valid values: `ResourceReference`: the referenced resource's physical ID may change. `ParameterReference`: a referenced template parameter may change. `ResourceAttribute`: a referenced resource output property may change. `DirectModification`: the template was directly modified. `Automatic`: for unmodified nested stacks (`ALIYUN::ROS::Stack`), ROS sets `ChangeSource` to `Automatic` because the nested template may have changed. ROS does not update the nested template until the parent stack is updated. `System`: internal mechanisms (such as `ALIYUN::ROS::WaitConditionHandle`) trigger an update regardless of input changes.
CausingEntity	String	The entity associated with `ChangeSource`. The mapping between ChangeSource and CausingEntity values: `ResourceReference`: the resource name. `ParameterReference`: the parameter name. `ResourceAttribute`: in the format `Resource name.Parameter name`. `DirectModification`: null. `Automatic`: the resource name. `System`: the resource name.
Evaluation	String	Whether ROS can determine the target value before change set execution. Valid values: `Static`: ROS can determine the target value before execution. `Dynamic`: ROS cannot determine the target value. The value may depend on intrinsic functions such as `Ref` or `Fn::GetAtt`.
Target	Structure	The entity that triggers the update.

ResourceTargetDefinition

Parameter	Type	Description
Attribute	String	The attribute that triggers the update. Valid values: `Properties`: the Properties parameter of the resource `Metadata`: the Metadata parameter of the resource `DeletionPolicy`: the DeletionPolicy parameter of the resource
Name	String	When `Attribute` is `Properties`, Name is the property name. Otherwise, Name is `null`.
RequiresRecreation	String	Whether changing this property recreates the resource. Takes effect only when `Attribute` is `Properties`. Valid values: `Never`: the property change does not require recreation. `Conditionally`: the property change may require recreation. `Always`: the property change always requires recreation.

ResourcePropertyChange

Parameter	Type	Description
Name	String.	The property name.
BeforeValue	The data type varies based on the property.	The property value before the update.
AfterValue	The data type varies based on the property.	The property value after the update. Note If the value is `<known_after_apply>` (String type), the value is available only after creation or update. If the value is `<sensitive>` (String type), the value contains sensitive data.

ModuleInfo

Parameter

Type

Description

LogicalIdHierarchy

String

The logical IDs of modules containing the resource, concatenated from outermost to innermost and separated by forward slashes (/).

Example: a resource created from Module B nested in Module A:

moduleA/moduleB

TypeHierarchy

String

The types of modules containing the resource, concatenated from outermost to innermost and separated by forward slashes (/).

Example: a resource from MODULE::ROS::Child::Example nested in MODULE::ROS::Parent::Example:

MODULE::ROS::Parent::Example/MODULE::ROS::Child::Example

References

To view JSON changes in a change set, follow View a change set.