get_attribute

Updated on 2023-08-11 GMT+08:00

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The get_attribute function is used to obtain the initialization results of other elements in a template.

Syntax

get_attribute: [resourceName, attributeName ]

If the content corresponding to attributeName is a structure body and contains multiple key-value fields, you can extend the definition. The format is as follows:

get_attribute: [resourceName, attributeName1, attributeName2, [...]]

Parameter Description

**Table 1** Parameter description
Parameter	Mandatory	Parameter Description
resourceName	Yes	Name of a resource customized in the template.
attributeName	Yes	Attribute name of the desired resource. For details about the attribute name, see the outputs section of the element object. If the attribute name defined in the template does not exist, no information is returned. Currently, for most elements, only their refID and refName can be obtained. refID: unique ID generated after a resource is created. refName: resource name.

Return Value

Attribute value obtained

When a single resource is created, the return values of refID and refName are strings.
When multiple resources are created (for example, multiple ECS VMs are created at a time), the return values of refID and refName are string arrays.

Examples

Obtain parameters and assign values to the parameters in the outputs section.

Example: Obtain the ID of the created my-first-vpc, and then assign it to the vpc_id output parameter of a stack.

tosca_definitions_version: huaweicloud_tosca_version_1_0
inputs:
  name:
    default: test-vpc
  cidr:
    default: 10.0.0.0/8  
node_templates:
  my-first-vpc:
    type: HuaweiCloud.VPC.VPC
    properties:
      name: {get_input: name}
      ciddr: {get_input: cidr}
outputs:
  vpc_id:
    value: {get_attribute: [my-first-vpc,refID]}

Obtain parameters and use them as input parameters for creating other resources.

Example: Obtain the ID of the created my-second-vpc and assign a value to the subnet resource as the input for creating the subnet resource. In this way, multiple resources can be created in one blueprint file.

node_templates:
  my-subnet:
    type: HuaweiCloud.VPC.Subnet
    properties:
      name: {get_input: subnet-name}
      cidr: {get_input: vpc-cidr}
      gateway: {get_input: subnet-gateway}
      dnsList: {get_input: dnsList}
      vpc: {get_attribute: [my-second-vpc,refID]}
      availabilityZone: {get_input: az}
    requirements:
      - vpc:
        node: my-vpc
        relationship: HuaweiCloud.Relationships.ContainedIn      
  my-second-vpc:
    type: HuaweiCloud.VPC.VPC
    properties:
      name: {get_input: vpc-name}
      cidr: {get_input: vpc-cidr}

Parent topic: Built-In Functions

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