Creating a Virtual Driver

Virtual Drivers provide a simple way to efficiently reuse complex driver inputs across multiple Resource Definitions. To a user, Virtual Drivers appear as a regular Driver, but underneath, they utilize a template to inject their Driver Inputs into a target driver. This template can not only transform inputs but also provide static values.
Virtual Drivers can be registered using the Register a new Resource Driver endpoint. For a Virtual Driver:
the target property should refer to an existing driver using the driver:// schema of the format driver://{orgId}/{driverId},
the template property defines a Go template that converts the driver inputs supplied in the resource definition into the driver inputs for the target driver.
Here is an example driver definition in YAML format demonstrating how a Virtual Driver called custom-redis can be defined which provisions an ElastiCache for Redis using the terraform driver:
id: custom-redis 
type: redis,
account_types:
- aws
inputs_schema:
  properties:
    values:
      properties:
        suffix:
          title: Name suffix
          description: The Name suffix will be appended to the current application and environment ID.
          type: string
      type: object
    secrets:
      properties:
        account:
          description: AWS credentials to use.
          properties:
            aws_access_key_id:
              type: string
            aws_secret_access_key:
              type: string
          type: object
    type: object
  type: object
target: "driver://humanitec/terraform"
template: |
  values:
    source:
      path: redis,
      rev: "refs/heads/main",
      url: "https://github.com/example-org/example-terraform.git"
    variables:
      name: ${context.app.id}-${context.env.id}-{{ .driver.values.suffix }}
  secrets:
    account:
      aws_access_key_id: {{ .driver.secrets.account.aws_access_key_id }}
      aws_secret_access_key: {{ .driver.secrets.account.aws_secret_access_key }}
​
Notes on the template:
The template should either be a string or an object containing string values. All string values will be evaluated as a template and interpreted as YAML.
Humanitec context placeholders such as ${context.app.id} are automatically expanded.
The inputs from the current driver can be referenced using .driver.values and .driver.secrets as necessary.
Virtual Driver templates support the same set of go template functions supported by Helm.
Last modified 1mo ago