Terraform 组件

对云资源的集成需求往往是最频繁出现，比如你可能希望数据库、中间件等服务使用阿里云、AWS 等云厂商的，以获得生产级别的可用性并免去运维的麻烦。 Terraform 是目前业内支持云资源最广泛也最受欢迎的组件，KubeVela 对 Terraform 进行了额外的支持，使得用户可以通过 Kubernetes CRD 的方式配合 Terraform 使用任意的云资源。

为了使最终用户能够部署和消费云资源，当用户的要求超出了 内置云资源的能力， 管理员需要要为云资源准备 ComponentDefinitions。

为云资源开发 ComponentDefinition

阿里云

以 弹性 IP为例。

为云资源开发一个 ComponentDefinition

这是 Terraform ComponentsDefinition 的脚手架。你只需要修改三个字段：metadata.name，metadata.annotations.definition.oam.dev/description 和 spec.schematic.terraform.configuration。

apiVersion: core.oam.dev/v1alpha2
kind: ComponentDefinition
metadata:
  name: # 1. ComponentDefinition name, like `alibaba-oss`
  namespace: {{.Values.systemDefinitionNamespace}}
  annotations:
    definition.oam.dev/description: # 2. description, like `Terraform configuration for Alibaba Cloud OSS object`
  labels:
    type: terraform
spec:
  workload:
    definition:
      apiVersion: terraform.core.oam.dev/v1beta1
      kind: Configuration
  schematic:
    terraform:
      configuration: |
        # 3. The developed Terraform HCL

这里阿里云 EIP 的完整的 ComponentDefinition，我们热烈欢迎你将扩展的云资源的 ComponentDefinition 贡献到 kubevela/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
        }

验证

你可以通过 vela show 命令快速验证 ComponentDefinition。

$ 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    |         |
+-----------+-----------------------------------------------------------------------------+--------+----------+---------+

如果表格能正常出来，ComponentDefinition 应该就可以工作了。更进一步，你可以通过文档部署云资源创建一个实际的 EIP 来验证。