kubevela.github.io/docs/platform-engineers/components/component-terraform.md

title
Terraform Components

To enable end users to provision and consume cloud resources, platform engineers need to prepare ComponentDefinitions for cloud resources if end users' requirements are beyond the built-in capabilities.

Develop a ComponentDefinition for a cloud resource

Alibaba Cloud

Take Elastic IP as an example.

Develop a Terraform resource or module for the cloud resource

We recommend you to search the required cloud resource module in Terraform official module registry. If no luck, you can create a Terraform resource or module yourself per Terraform Alibaba Cloud Provider specifications.

module "eip" {
  source = "github.com/zzxwill/terraform-alicloud-eip"
  name = var.name
  bandwidth = var.bandwidth
}

variable "name" {
  description = "Name to be used on all resources as prefix. Default to 'TF-Module-EIP'."
  default = "TF-Module-EIP"
  type = string
}

variable "bandwidth" {
  description = "Maximum bandwidth to the elastic public network, measured in Mbps (Mega bit per second)."
  type = number
  default = 5
}

output "EIP_ADDRESS" {
  description = "The elastic ip address."
  value       = module.eip.this_eip_address.0
}

For Alibaba Cloud EIP, here is the complete ComponentDefinition. You are warmly welcome to contribute this extended cloud resource ComponentDefinition to oam-dev/kubevela.

apiVersion: core.oam.dev/v1alpha2
kind: ComponentDefinition
metadata:
  name: alibaba-eip
  namespace: {{.Values.systemDefinitionNamespace}}
  annotations:
    definition.oam.dev/description: Terraform configuration for Alibaba Cloud Elastic IP
  labels:
    type: terraform
spec:
  workload:
    definition:
      apiVersion: terraform.core.oam.dev/v1beta1
      kind: Configuration
  schematic:
    terraform:
      configuration: |
        module "eip" {
          source = "github.com/zzxwill/terraform-alicloud-eip"
          name = var.name
          bandwidth = var.bandwidth
        }

        variable "name" {
          description = "Name to be used on all resources as prefix. Default to 'TF-Module-EIP'."
          default = "TF-Module-EIP"
          type = string
        }

        variable "bandwidth" {
          description = "Maximum bandwidth to the elastic public network, measured in Mbps (Mega bit per second)."
          type = number
          default = 5
        }

        output "EIP_ADDRESS" {
          description = "The elastic ip address."
          value       = module.eip.this_eip_address.0
        }        

Verify

You can quickly verify the ComponentDefinition by command vela show.

$ vela show alibaba-eip
# Properties
+----------------------------+------------------------------------------------------------------------------------------+-----------------------------------------------------------+----------+---------+
|            NAME            |                                       DESCRIPTION                                        |                           TYPE                            | REQUIRED | DEFAULT |
+----------------------------+------------------------------------------------------------------------------------------+-----------------------------------------------------------+----------+---------+
| name                       | Name to be used on all resources as prefix. Default to 'TF-Module-EIP'.                  | string                                                    | true     |         |
| bandwidth                  | Maximum bandwidth to the elastic public network, measured in Mbps (Mega bit per second). | number                                                    | true     |         |
| writeConnectionSecretToRef | The secret which the cloud resource connection will be written to                        | [writeConnectionSecretToRef](#writeConnectionSecretToRef) | false    |         |
+----------------------------+------------------------------------------------------------------------------------------+-----------------------------------------------------------+----------+---------+


## writeConnectionSecretToRef
+-----------+-----------------------------------------------------------------------------+--------+----------+---------+
|   NAME    |                                 DESCRIPTION                                 |  TYPE  | REQUIRED | DEFAULT |
+-----------+-----------------------------------------------------------------------------+--------+----------+---------+
| name      | The secret name which the cloud resource connection will be written to      | string | true     |         |
| namespace | The secret namespace which the cloud resource connection will be written to | string | false    |         |
+-----------+-----------------------------------------------------------------------------+--------+----------+---------+

If the tables display, the ComponentDefinition should work. To take a step further, you can verify it by provision an actual EIP instance per the doc Provision cloud resources.