instance

type Attachment struct {
	// ID is the unique identifier for the attachment.
	ID string

	// Type is the kind of attachment.  This allows multiple attachments of different types, with the supported
	// types defined by the plugin.
	Type string
}

type Description struct {
	ID        ID
	LogicalID *LogicalID
	Tags      map[string]string
}

type ID string

type LogicalID string

type Plugin interface {
	// Validate performs local validation on a provision request.
	Validate(req json.RawMessage) error

	// Provision creates a new instance based on the spec.
	Provision(spec Spec) (*ID, error)

	// Destroy terminates an existing instance.
	Destroy(instance ID) error

	// DescribeInstances returns descriptions of all instances matching all of the provided tags.
	DescribeInstances(tags map[string]string) ([]Description, error)
}

type Spec struct {
	// Properties is the opaque instance plugin configuration.
	Properties *json.RawMessage

	// Tags are metadata that describes an instance.
	Tags map[string]string

	// Init is the boot script to execute when the instance is created.
	Init string

	// LogicalID is the logical identifier assigned to this instance, which may be absent.
	LogicalID *LogicalID

	// Attachments are instructions for external entities that should be attached to the instance.
	Attachments []Attachment
}