opentofu/README.md

# Terraform

* Website: http://www.terraform.io
* IRC: `#terraform-tool` on Freenode
* Mailing list: [Google Groups](http://groups.google.com/group/terraform-tool)

![Terraform](https://raw.githubusercontent.com/hashicorp/terraform/master/website/source/images/readme.png)

Terraform is a tool for building, changing, and versioning infrastructure
safely and efficiently. Terraform can manage existing and popular service
providers as well as custom in-house solutions.

The key features of Terraform are:

* **Infrastructure as Code**: Infrastructure is described using a high-level
  configuration syntax. This allows a blueprint of your datacenter to be
  versioned and treated as you would any other code. Additionally,
  infrastructure can be shared and re-used.

* **Execution Plans**: Terraform has a "planning" step where it generates
  an _execution plan_. The execution plan shows what Terraform will do when
  you call apply. This lets you avoid any surprises when Terraform
  manipulates infrastructure.

* **Resource Graph**: Terraform builds a graph of all your resources,
  and parallelizes the creation and modification of any non-dependent
  resources. Because of this, Terraform builds infrastructure as efficiently
  as possible, and operators get insight into dependencies in their
  infrastructure.

* **Change Automation**: Complex changesets can be applied to
  your infrastructure with minimal human interaction.
  With the previously mentioned execution
  plan and resource graph, you know exactly what Terraform will change
  and in what order, avoiding many possible human errors.

For more information, see the
[introduction section](http://www.terraform.io/intro)
of the Terraform website.

## Getting Started & Documentation

All documentation is available on the
[Terraform website](http://www.terraform.io).

## Developing Terraform

If you wish to work on Terraform itself or any of its built-in providers,
you'll first need [Go](http://www.golang.org) installed (version 1.2+ is
_required_). Make sure Go is properly installed, including setting up
a [GOPATH](http://golang.org/doc/code.html#GOPATH).

Next, install the following software packages, which are needed for some dependencies:

- [Git](http://git-scm.com/)
- [Mercurial](http://mercurial.selenic.com/)

Then, install [Gox](https://github.com/mitchellh/gox), which is used
as a compilation tool on top of Go:

    $ go get -u github.com/mitchellh/gox

Next, clone this repository into `$GOPATH/src/github.com/hashicorp/terraform`.
Install the necessary dependencies by running `make updatedeps` and then just
type `make`. This will compile some more dependencies and then run the tests. If
this exits with exit status 0, then everything is working!

    $ make updatedeps
    ...
    $ make
    ...

To compile a development version of Terraform and the built-in plugins,
run `make dev`. This will put Terraform binaries in the `bin` folder:

    $ make dev
    ...
    $ bin/terraform
    ...


If you're developing a specific package, you can run tests for just that
package by specifying the `TEST` variable. For example below, only
`terraform` package tests will be run.

    $ make test TEST=./terraform
    ...

### Acceptance Tests

Terraform also has a comprehensive
[acceptance test](http://en.wikipedia.org/wiki/Acceptance_testing)
suite covering most of the major features of the built-in providers.

If you're working on a feature of a provider and want to verify it
is functioning (and hasn't broken anything else), we recommend running
the acceptance tests. Note that we _do not require_ that you run or
write acceptance tests to have a PR accepted. The acceptance tests
are just here for your convenience.

**Warning:** The acceptance tests create/destroy/modify _real resources_,
which may incur real costs. In the presence of a bug, it is technically
possible that broken providers could corrupt existing infrastructure
as well. Therefore, please run the acceptance providers at your own
risk. At the very least, we recommend running them in their own private
account for whatever provider you're testing.

To run the acceptance tests, invoke `make testacc`:

    $ make testacc TEST=./builtin/providers/aws TESTARGS='-run=VPC'
    ...

The `TEST` variable is required, and you should specify the folder where
the provider is. The `TESTARGS` variable is recommended to filter down
to a specific resource to test, since testing all of them at once can
take a very long time.

Acceptance tests typically require other environment variables to be
set for things such as access keys. The provider itself should error
early and tell you what to set, so it is not documented here.