You can use Fixie with any Elixir HTTP client. Below is an example of using it with the popular Req library.

Using Req

First, you need to add the Req library to your project if you haven't already:

defp deps do
  [
    {:req, "~> 0.3.0"}
  ]
end

Next, configure the HTTP request to use a proxy. The following example demonstrates how to set up proxy options by extracting the necessary environment variables and adding basic authentication to the proxy headers:

...
import Base
import URI

def connect_options() do
  fixie_url = System.get_env("FIXIE_URL")
  %URI{userinfo: userinfo, host: proxy_host} = URI.parse(fixie_url)
  [proxy_username, proxy_password] = String.split(userinfo, ":")

  proxy_auth = Base.encode64("#{proxy_username}:#{proxy_password}")

  [
    proxy: {:http, proxy_host, 80, []},
    proxy_headers: [
      {"Proxy-Authorization", "Basic #{proxy_auth}"}
    ]
  ]
end

def post_request(url, form) do
  Req.post!(url, form: form, connect_options: connect_options())
end

In the example above:

• proxy_username, proxy_password, and proxy_host are parsed from FIXIE_URL variables.
• proxy_auth is encoded using Base.encode64 to create the authorization header.
• The connect_options function returns a list of options, including the proxy settings and headers, which are then used in the Req.post!/3 call.

To make a POST request through the proxy using Req, you can call the post_request/2 function:

post_request("http://welcome.usefixie.com", %{key: "value"})

This configuration will route the HTTP request through the specified proxy, including the necessary authentication.