README.md

# terraform [![Hex](https://img.shields.io/hexpm/v/terraform.svg)](https://hex.pm/packages/terraform) [![CircleCI](https://circleci.com/gh/poteto/terraform/tree/master.svg?style=shield)](https://circleci.com/gh/poteto/terraform/tree/master)

Terraform is a simple `Plug` designed to work with Phoenix. Terraform allows you to incrementally transform an older API into one powered by Phoenix - one endpoint at a time.

View the [demo Phoenix app](https://github.com/poteto/reverse_proxy).

## Installation

Add `terraform` to your list of dependencies in `mix.exs`:

```elixir
def deps do
  [{:terraform, "~> 1.0.0"}]
end
```

## Usage

First, add it to `web/router.ex`:

```elixir
defmodule MyApp.Router do
  use Terraform, terraformer: MyApp.Terraformers.Foo

  # ...
end
```

Then, define a new `Terraformer`, which uses `Plug.Router`. Any request that goes to a route that isn't defined on your Phoenix app will hit this plug, and you can then handle it using a familiar DSL:

```elixir
defmodule MyApp.Terraformers.Foo do
  alias MyApp.Clients.Foo # example client made with HTTPoison
  use Plug.Router

  plug :match
  plug :dispatch

  # match specific path
  get "/v1/hello-world", do: send_resp(conn, 200, "Hello world")

  # match all `get`s
  get _ do
    %{method: "GET", request_path: request_path, params: params, req_headers: req_headers} = conn
    res = Foo.get!(request_path, req_headers, [params: Map.to_list(params)])
    send_response({:ok, conn, res})
  end

  def send_response({:ok, conn, %{headers: headers, status_code: status_code, body: body}}) do
    conn = %{conn | resp_headers: headers}
    send_resp(conn, status_code, body)
  end
end
```