# ReqIMDSv2
Provides a way to automatically authenticate Req requests with the Instance Metadata Service on
an Amazon AWS EC2 instance.
It does this by making a request to IMDSv2 to get a token before the main request, then attaches that token
to the request.
## Features
- Integrates easily with [Req](https://hexdocs.pm/req).
- Handles the extra step of fetching and using a metadata token from IMDSv2.
- Fetches the token from the same host as the original request.
- Supports extracting the metadata token for re-use on subsequent requests.
- Can enable `:fallback_to_imdsv1` if desired, in the case that IMDSv2 fails. (highly unlikely.)
## Installation
The package can be installed from [hex.pm](https://hex.pm/packages/req_imdsv2) by adding `req_imdsv2` to
your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:req, "~> 0.4.0"},
{:req_imdsv2, "~> 0.1.0"}
]
end
```
## Documentation
Documentation is available from [hexdocs.pm](https://hexdocs.pm/req_imdsv2).
## Usage
This will work on an instance that has IMDSv2 required, and will not answer to IMDSv1 requests.
```elixir
Req.new(url: "http://169.254.169.254/latest/meta-data/instance-id")
|> ReqIMDSv2.attach()
|> Req.get!().body
"i-1234567890abcdef0"
```
See the `ReqIMDSv2` module for more information and examples.