Resource Orchestration Service:Resources

Resources:
  ID of Resource 1:
    Type: the resource type.
    Condition: the condition based on which the resource is created.
    Properties: the descriptions of resource properties.
  ID of Resource 2:
    Type: the resource type.
    Condition: the condition based on which the resource is created.
    Properties: the descriptions of resource properties.

Resources:
  ECSInstance:
    Type: ALIYUN::ECS::Instance
    Properties:
      ImageId: m-25l0r****

Property values can be text strings, string lists, booleans, referenced parameters, or return values of functions. The following information describes the rules for property values:

• Text strings must be enclosed in double quotation marks (" ").
• String lists must be enclosed in brackets ([ ]).
• Referenced parameters or return values of built-in functions must be enclosed in braces ({ }).

The preceding rules also apply when you combine text strings, string lists, referenced parameters, and return values of functions as property values.

Properties:
  String: string
  LiteralList:
    - value1
    - value2
  Boolean: true
  ReferenceForOneValue:
    Ref: ResourceID
  FunctionResultWithFunctionParams:
    Fn::Join:
      - '%'
      - - Key=
        - Ref: SomeParameter

You can specify the DeletionPolicy property in a template to retain a specified resource when a stack is deleted. The following sample code provides an example on how to declare the DeletionPolicy property to retain an ECS instance when the stack that contains the instance is deleted:

Resources:
  ECSInstance:
    Type: ALIYUN::ECS::Instance
    Properties:
      ImageId: m-25l0r****
    DeletionPolicy: Retain

The following sample code provides examples on how to configure dependent resources:

• Configure a single dependent resource.

  DependsOn: ResourceName

• Configure multiple dependent resources.

  DependsOn:
    - ResourceName1
    - ResourceName2

The following sample code provides an example on how to specify the DependsOn property. In this example, WebServer is created only after DatabaseServer is created.

ROSTemplateFormatVersion: '2015-09-01'
Resources:
  WebServer:
    Type: ALIYUN::ECS::Instance
    DependsOn: DatabseServer
  DatabseServer:
    Type: ALIYUN::ECS::Instance
    Properties:
      ImageId: m-25l0r****
      InstanceType: ecs.t1.small

The following sample code provides an example on how to specify the Condition property. In this example, whether WebServer is created is determined based on the value of MaxAmount.

ROSTemplateFormatVersion: '2015-09-01'
Parameters:
  MaxAmount:
    Type: Number
    Default: 1
Conditions:
  CreateWebServer:
    Fn::Not:
      Fn::Equals:
        - 0
        - Ref: MaxAmount
Resources:
  WebServer:
    Type: ALIYUN::ECS::InstanceGroup
    Condition: CreateWebServer
    Properties:
      ImageId: m-25l0rc****
      InstanceType: ecs.t1.small
      MaxAmount:
        Ref: MaxAmount
  DatabseServer:
    Type: ALIYUN::ECS::Instance
    Properties:
      ImageId: m-25l0r****
      InstanceType: ecs.t1.small

You can specify the Count property for a resource in a template to preprocess the template and replace the resource with multiplied resources. When you use a template for which the Count property is specified to perform operations on a stack, the systems uses the processed template.

• For example, you set the Count property of Resource A to 3 in the original template. After ROS preprocesses the template, Resource A is replaced with the following multiplied resources: Resources A[0], A[1], and A[2]. The following sample code provides an example on the original template:

  Resources:
    A:
      Count: 3
      ...: Null
    ...: Null

  The following sample code provides an example on the processed template:

  Resources:
    A[0]:
      ...: Null
    A[1]:
      ...: Null
    A[2]:
      ...: Null
    ...: Null

  Important If the name of a multiplied resource, such as A[1], is the same as the name of an existing resource that is defined in the original template, the template fails to be preprocessed and validated.

  If you specify Count for a resource, the resource name is changed. We recommend that you do not add the Count property to existing resources to prevent deletion of the resources.

• The value of the Count property must be a natural number. The property value supports only the following functions. You can invoke only the Ref function in Count to reference parameters.
  • Ref
  • Fn::FindInMap
  • Fn::Select
  • Fn::Join
  • Fn::Split
  • Fn::Replace
  • Fn::Str
  • Fn::Base64Decode
  • Fn::If
  • Fn::ListMerge
  • Fn::GetJsonValue
  • Fn::MergeMapToList
  • Fn::SelectMapList
  • Fn::Add
  • Fn::Avg
  • Fn::Str
  • Fn::Calculate
  • Fn::Max
  • Fn::Min
  • Fn::Jq
  • Fn::Length
  • Fn::GetAZs
  • Fn::Index
  • Fn::FormatTime
  • Fn::MarketplaceImage
• The maximum number of resources in a processed template cannot exceed 300.
• You can specify the ALIYUN::Index pseudo parameter in Properties of a resource for which the Count property is specified. When the system preprocesses the template, the system replaces ALIYUN::Index with the values that correspond to expanded resources. For example, the system replaces ALIYUN::Index that is applied to A[0] with 0 and replaces ALIYUN::Index that is applied to A[1] with 1. You can use ALIYUN::Index only in Properties of a template.
• If you specify Count for a resource and specify the resource in DependsOn, the resource is replaced with multiplied resources. The following sample code provides an example on the original template:

  DependsOn: A

  The following sample code provides an example on the processed template:

  DependsOn:
    - A[0]
    - A[1]
    - A[2]

• If you specify Count for a resource and specify the resource in Ref and Fn::GetAtt, the resource is replaced with multiplied resources. The following sample code provides an example on the original template:

  Ref: A
  Fn::GetAtt:
    - A
    - PropertyName

  The following sample code provides an example on the processed template:

  - Ref: A[0]
  - Ref: A[1]
  - Ref: A[2]
  - Fn::GetAtt:
      - A[0]
      - PropertyName
  - Fn::GetAtt:
      - A[1]
      - PropertyName
  - Fn::GetAtt:
      - A[2]
      - PropertyName

  If you specify the Count property for multiple resources and the resources are referenced by each other, we recommend that you use Count together with Fn::Select and ALIYUN::Index.

  Fn::Select:
    - Ref: ALIYUN::Index
    - Ref: A

  In this example, Resource A is used. You reference Resource A in Resource B, and set the Count property of Resource B to 2. The following sample code provides an example on a part of the expressions of Resources B[0] and B[1] after the template is processed:

  - Ref: A[0]
  - Ref: A[1]

• If you specify the Count property for a resource, the DependsOn property also supports expressions. The functions that are supported by the expressions of the DependsOn property are the same as the functions that are supported by the expressions of the Count property. Both properties also support the ALIYUN::Index pseudo parameter. The following table describes the formats and the calculation results of the expressions.

  Format	Example	Calculation result
  Dictionary	Fn::Split: - ',' - Server1,Server2	null. If the calculation result is null, the system removes the DependsOn property.
  		A string. If the calculation result is an empty string, the system removes the DependsOn property. If the calculation result is not an empty string, the calculation result must be a valid resource name.
  		A list. If the items in the list are null or empty strings, the system removes the items. If the list is empty, the system removes the DependsOn property. If the list is not empty, each item in the list must be a string and a valid resource name.
  List	- Server0 - Fn::Split: - ',' - Server1,Server2	The items in a list can be dictionaries or strings. Calculation results vary based on the item types. The following information describes the differences: If the items are dictionaries, the system calculates the expressions and returns the following calculation results: If the items are null or empty strings, the system removes the items. If the items are not null or empty strings, the items must be strings and valid resource names. If the items are strings, the items must be valid resource names. Note If the list is empty, the system removes the DependsOn property.
  String	Server0	A string. The system does not process a string.

  The following template shows how to specify Count to control the number of resources that can be created, and specify ParallelCount to control the maximum number of resources that can be created at a time.

  ROSTemplateFormatVersion: '2015-09-01'
  Parameters:
    Count:
      Type: Number
    ParallelCount:
      Type: Number
  Resources:
    WaitConditionHandle:
      Type: ALIYUN::ROS::WaitConditionHandle
      Count:
        Ref: Count
      DependsOn:
        Fn::Select:
          - Fn::Calculate:
              - 1-{0}//{1}
              - 0
              - - Fn::Min:
                    - Ref: ALIYUN::Index
                    - Ref: ParallelCount
                - Ref: ParallelCount
          - - Fn::Replace:
                - index:
                    Fn::Calculate:
                      - '{0}-{1}'
                      - 0
                      - - Ref: ALIYUN::Index
                        - Ref: ParallelCount
                - WaitConditionHandle[index]

  The processed templates that the system generates vary based on the values that you specify for Count and ParallelCount.

  • If you set Count to 3 and ParallelCount to 1, the system generates the following processed template:

    ROSTemplateFormatVersion: '2015-09-01'
    Resources:
      WaitConditionHandle[0]:
        Type: ALIYUN::ROS::WaitConditionHandle
      WaitConditionHandle[1]:
        Type: ALIYUN::ROS::WaitConditionHandle
        DependsOn: WaitConditionHandle[0]
      WaitConditionHandle[2]:
        Type: ALIYUN::ROS::WaitConditionHandle
        DependsOn: WaitConditionHandle[1]
    Parameters:
      Count:
        Type: Number
      ParallelCount:
        Type: Number

  • If you set Count to 5 and ParallelCount to 2, the system generates the following processed template:

    ROSTemplateFormatVersion: '2015-09-01'
    Resources:
      WaitConditionHandle[0]:
        Type: ALIYUN::ROS::WaitConditionHandle
      WaitConditionHandle[1]:
        Type: ALIYUN::ROS::WaitConditionHandle
      WaitConditionHandle[2]:
        Type: ALIYUN::ROS::WaitConditionHandle
        DependsOn: WaitConditionHandle[0]
      WaitConditionHandle[3]:
        Type: ALIYUN::ROS::WaitConditionHandle
        DependsOn: WaitConditionHandle[1]
      WaitConditionHandle[4]:
        Type: ALIYUN::ROS::WaitConditionHandle
        DependsOn: WaitConditionHandle[2]
    Parameters:
      Count:
        Type: Number
      ParallelCount:
        Type: Number

  • If you set Count to 5 and ParallelCount to 3, the system generates the following processed template:

    ROSTemplateFormatVersion: '2015-09-01'
    Resources:
      WaitConditionHandle[0]:
        Type: ALIYUN::ROS::WaitConditionHandle
      WaitConditionHandle[1]:
        Type: ALIYUN::ROS::WaitConditionHandle
      WaitConditionHandle[2]:
        Type: ALIYUN::ROS::WaitConditionHandle
      WaitConditionHandle[3]:
        Type: ALIYUN::ROS::WaitConditionHandle
        DependsOn: WaitConditionHandle[0]
      WaitConditionHandle[4]:
        Type: ALIYUN::ROS::WaitConditionHandle
        DependsOn: WaitConditionHandle[1]
    Parameters:
      Count:
        Type: Number
      ParallelCount:
        Type: Number

ROSTemplateFormatVersion: '2015-09-01'
Parameters:
  Count:
    Type: Number
Resources:
  Eip:
    Type: ALIYUN::VPC::EIP
    Count:
      Ref: Count
    Properties:
      Bandwidth: 5
  Servers:
    Type: ALIYUN::ECS::InstanceGroup
    Properties:
      MinAmount:
        Ref: Count
      MaxAmount:
        Ref: Count
      AllocatePublicIP: false
      ...: Null
  EipBind:
    Type: ALIYUN::VPC::EIPAssociation
    Count:
      Ref: Count
    Properties:
      InstanceId:
        Fn::Select:
          - Ref: ALIYUN::Index
          - Fn::GetAtt:
              - Servers
              - InstanceIds
      AllocationId:
        Fn::Select:
          - Ref: ALIYUN::Index
          - Ref: Eip
Outputs:
  InstanceIds:
    Value:
      Fn::GetAtt:
        - Servers
        - InstanceIds
  AllocationIds:
    Value:
      Ref: Eip
  EipAddresses:
    Value:
      Fn::GetAtt:
        - Eip
        - EipAddress

ROSTemplateFormatVersion: '2015-09-01'
Parameters:
  Count:
    Type: Number
Resources:
  Eip[0]:
    Type: ALIYUN::VPC::EIP
    Properties:
      Bandwidth: 5
  Eip[1]:
    Type: ALIYUN::VPC::EIP
    Properties:
      Bandwidth: 5
  Servers:
    Type: ALIYUN::ECS::InstanceGroup
    Properties:
      MinAmount:
        Ref: Count
      MaxAmount:
        Ref: Count
      AllocatePublicIP: false
      ...: Null
  EipBind[0]:
    Type: ALIYUN::VPC::EIPAssociation
    Properties:
      InstanceId:
        Fn::Select:
          - 0
          - Fn::GetAtt:
              - Servers
              - InstanceIds
      AllocationId:
        Ref: Eip[0]
  EipBind[1]:
    Type: ALIYUN::VPC::EIPAssociation
    Properties:
      InstanceId:
        Fn::Select:
          - 1
          - Fn::GetAtt:
              - Servers
              - InstanceIds
      AllocationId:
        Ref: Eip[1]
Outputs:
  InstanceIds:
    Value:
      Fn::GetAtt:
        - Servers
        - InstanceIds
  AllocationIds:
    Value:
      - Ref: Eip[0]
      - Ref: Eip[1]
  EipAddresses:
    Value:
      - Fn::GetAtt:
          - Eip[0]
          - EipAddress
      - Fn::GetAtt:
          - Eip[1]
          - EipAddress