external
is a special provider that exists to provide an interface between Terraform and external programs.
Using this provider it is possible to write separate programs that can participate in the Terraform workflow by implementing a specific protocol.
This provider is intended to be used for simple situations where you wish to integrate Terraform with a system for which a first-class provider doesn't exist. It is not as powerful as a first-class Terraform provider, so users of this interface should carefully consider the implications described on each of the child documentation pages (available from the navigation bar) for each type of object this provider supports.
Warning Terraform Enterprise does not guarantee availability of any particular language runtimes or external programs beyond standard shell utilities, so it is not recommended to use this provider within configurations that are applied within Terraform Enterprise.
© 2018 HashiCorpLicensed under the MPL 2.0 License.
https://www.terraform.io/docs/providers/external/index.html