ALIYUN::ROS::Stack is used to create a nested stack. You can have a maximum of five nested levels.
Nested stacks can themselves contain other nested stacks. This results in a hierarchy of stacks. The root stack is the top-level stack to which all the nested stacks belong. The template of the root stack is called the top-level template. The ALIYUN::ROS::Stack type nests a stack as a resource in a top-level template.
In a nested stack template, you can use outputs from one stack as inputs to another stack. To obtain the output of the nested stack, you can use the Fn::GetAtt function and set the function parameters to the name of the nested stack and the output value in the Outputs.NestedStackOutputName format. For more information, see Use nested stacks.
Syntax
{
"Type": "ALIYUN::ROS::Stack",
"Properties": {
"TemplateURL": String,
"TemplateBody": String,
"TemplateId": String,
"TemplateVersion": String,
"TimeoutMins": Number,
"Parameters": Map,
"ResourceGroupId": String
}
}Properties
| Property | Type | Required | Editable | Description | Constraint |
|---|---|---|---|---|---|
| TemplateURL | String | No | Yes | The URL of the file that contains the template body. | The file that contains the template body can be up to 524,288 bytes in size. The URL
can be up to 1,024 bytes in length.
The URL must point to a template that is located in an HTTP or HTTPS web server or
an Object Storage Service (OSS) bucket. Example: If the region of the OSS bucket is not specified, the RegionId parameter value is used by default. You must specify one of the |
| TemplateBody | Map | No | Yes | The structure that contains the template body, which is used to facilitate the delivery of the template. |
The content is raw data. Functions in the template body are not resolved in the parent stack. You must specify one of the |
| TemplateId | String | No | Yes | The ID of the template. |
You must specify one of the |
| TemplateVersion | String | No | Yes | The name of the template version. | None |
| TimeoutMins | Number | No | Yes | The timeout period for creating or updating a stack. | Unit: minutes.
Default value: 60. |
| Parameters | Map | No | Yes | A set of key-value pairs that represent the parameters passed to Resource Orchestration Service (ROS) when the nested stack is created. | Each parameter has a key corresponding to a parameter name defined in the template of the nested stack and a value representing the value that you want to set for the parameter. This parameter is required if the nested stack requires input parameters. |
| ResourceGroupId | String | No | No | The ID of the resource group. | None |
Response parameters
Fn::GetAtt
You can use the following code to obtain the output of the nested stack:
{
"Fn::GetAtt": [
"<nested_stack>",
"Outputs.<nested_stack_output_name>"
]
}When you use Ref to reference resources in a nested stack, the Alibaba Cloud Resource Name (ARN) of
the nested stack is returned. Example: arn:acs:ros::cn-hangzhou:12345****:stacks/test-nested-stack-Demo-jzkyq7mn****/e71c1e04-1a57-46fc-b9a4-cf7ce0d3****.
Examples
The following code provides an example on how to create a virtual private cloud (VPC), a vSwitch, and a security group in a nested stack and save the output results to the oss://ros/template/vpc.txt directory:
-
JSONformat{ "ROSTemplateFormatVersion": "2015-09-01", "Description": "One VPC, vSwitch, security group.", "Parameters": { "ZoneId": { "Type": "String", "Description": "The available zone" }, "SecurityGroupName": { "Type": "String", "Description": "The security group name", "Default": "my-sg-name" }, "VpcName": { "Type": "String", "Description": "The VPC name", "MinLength": 2, "MaxLength": 128, "ConstraintDescription": "[2, 128] English or Chinese letters", "Default": "my-vpc-name" }, "VpcCidrBlock": { "Type": "String", "AllowedValues": [ "192.168.0.0/16", "172.16.0.0/12", "10.0.0.0/8" ], "Default": "10.0.0.0/8" }, "VSwitchCidrBlock": { "Type": "String", "Description": "The vSwitch subnet which must be within VPC", "Default": "10.0.10.0/24" }, "UpdateVersion": { "Type": "Number", "Default": 0 } }, "Resources": { "Vpc": { "Type": "ALIYUN::ECS::VPC", "Properties": { "CidrBlock": { "Ref": "VpcCidrBlock" }, "VpcName": { "Ref": "VpcName" } } }, "VSwitch": { "Type": "ALIYUN::ECS::VSwitch", "Properties": { "CidrBlock": { "Ref": "VSwitchCidrBlock" }, "ZoneId": { "Ref": "ZoneId" }, "VpcId": { "Fn::GetAtt": [ "Vpc", "VpcId" ] } } }, "SecurityGroup": { "Type": "ALIYUN::ECS::SecurityGroup", "Properties": { "SecurityGroupName": { "Ref": "SecurityGroupName" }, "VpcId": { "Ref": "Vpc" } } }, "WaitConditionHandle": { "Type": "ALIYUN::ROS::WaitConditionHandle", "Properties": { "UpdateVersion": { "Ref": "UpdateVersion" } } } }, "Outputs": { "SecurityGroupId": { "Value": { "Fn::GetAtt": [ "SecurityGroup", "SecurityGroupId" ] } }, "VpcId": { "Value": { "Fn::GetAtt": [ "Vpc", "VpcId" ] } }, "VSwitchId": { "Value": { "Fn::GetAtt": [ "VSwitch", "VSwitchId" ] } } } }
Example of a parent stack
-
JSONformat{ "ROSTemplateFormatVersion": "2015-09-01", "Description": "One ECS instance.", "Parameters": { "ImageId": { "Default": "centos_7", "Type": "String", "Description": "Image Id, represents the image resource to startup the ECS instance" }, "InstanceType": { "Type": "String", "Description": "The ECS instance type,", "Default": "ecs.xn4.small" }, "ZoneId": { "Type": "String", "Description": "The available zone " }, "InstanceChargeType": { "Type": "String", "AllowedValues": [ "PrePaid", "PostPaid" ], "Default": "PostPaid", "Description": "The instance charge type" }, "SecurityGroupName": { "Type": "String", "Description": "The security group name", "Default": "my-sg-name" }, "NetworkInterfaceName": { "Type": "String", "Description": "The Network interface name", "Default": "my-eni-name" }, "VpcName": { "Type": "String", "Description": "The VPC name", "MinLength": 2, "MaxLength": 128, "ConstraintDescription": "[2, 128] English or Chinese letters", "Default": "my-vpc-name" }, "IoOptimized": { "AllowedValues": [ "none", "optimized" ], "Description": "IO optimized, optimized is for the IO optimized instance type", "Type": "String", "Default": "optimized" }, "SystemDiskCategory": { "AllowedValues": [ "cloud", "cloud_efficiency", "cloud_ssd" ], "Description": "System disk category: average cloud disk(cloud), efficient cloud disk(cloud_efficiency) or SSD cloud disk(cloud_ssd)", "Type": "String", "Default": "cloud_ssd" }, "VpcCidrBlock": { "Type": "String", "AllowedValues": [ "192.168.0.0/16", "172.16.0.0/12", "10.0.0.0/8" ], "Default": "10.0.0.0/8" }, "VSwitchCidrBlock": { "Type": "String", "Description": "The VSwitch subnet which must be within VPC", "Default": "10.0.10.0/24" }, "UpdateVersion": { "Type": "Number", "Default": 0 } }, "Resources": { "NetworkStack": { "Type": "ALIYUN::ROS::Stack", "Properties": { "TemplateURL": "oss://ros/template/vpc.txt", "TimeoutMins": 5, "Parameters": { "ZoneId": { "Ref": "ZoneId" }, "SecurityGroupName": { "Ref": "SecurityGroupName" }, "VpcName": { "Ref": "VpcName" }, "VpcCidrBlock": { "Ref": "VpcCidrBlock" }, "VSwitchCidrBlock": { "Ref": "VSwitchCidrBlock" }, "UpdateVersion": { "Ref": "UpdateVersion" } } } }, "WebServer": { "Type": "ALIYUN::ECS::Instance", "Properties": { "ImageId": { "Ref": "ImageId" }, "InstanceType": { "Ref": "InstanceType" }, "InstanceChargeType": { "Ref": "InstanceChargeType" }, "SecurityGroupId": { "Fn::GetAtt": [ "NetworkStack", "Outputs.SecurityGroupId" ] }, "VpcId": { "Fn::GetAtt": [ "NetworkStack", "Outputs.VpcId" ] }, "VSwitchId": { "Fn::GetAtt": [ "NetworkStack", "Outputs.VSwitchId" ] }, "IoOptimized": { "Ref": "IoOptimized" }, "ZoneId": { "Ref": "ZoneId" }, "SystemDisk_Category": { "Ref": "SystemDiskCategory" }, "DiskMappings": [ { "Category": "cloud_ssd", "Size": 20 } ] } } }, "Outputs": { "InstanceId": { "Value": { "Fn::GetAtt": [ "WebServer", "InstanceId" ] } }, "PublicIp": { "Value": { "Fn::GetAtt": [ "WebServer", "PublicIp" ] } }, "SecurityGroupId": { "Value": { "Fn::GetAtt": [ "NetworkStack", "Outputs.SecurityGroupId" ] } }, "VpcId": { "Value": { "Fn::GetAtt": [ "NetworkStack", "Outputs.VpcId" ] } }, "VSwitchId": { "Value": { "Fn::GetAtt": [ "NetworkStack", "Outputs.VSwitchId" ] } }, "NetworkStackArn": { "Value": { "Ref": "NetworkStack" } } } }
For more examples, see MongoDBInstance.json and MongoDBInstance.yml.