GitHub OAuth2 strategy for Überauth.

1. Setup your application at GitHub Developer.

2. Add :ueberauth_github to your list of dependencies in mix.exs:

   def deps do
     [{:ueberauth_github, "~> 0.4"}]
   end

3. Add the strategy to your applications:

   def application do
     [applications: [:ueberauth_github]]
   end

4. Add GitHub to your Überauth configuration:

   config :ueberauth, Ueberauth,
     providers: [
       github: {Ueberauth.Strategy.Github, []}
     ]

5. Update your provider configuration:

   config :ueberauth, Ueberauth.Strategy.Github.OAuth,
     client_id: System.get_env("GITHUB_CLIENT_ID"),
     client_secret: System.get_env("GITHUB_CLIENT_SECRET")

6. Include the Überauth plug in your controller:

   defmodule MyApp.AuthController do
     use MyApp.Web, :controller
   
     pipeline :browser do
       plug Ueberauth
       ...
      end
   end

7. Create the request and callback routes if you haven't already:

   scope "/auth", MyApp do
     pipe_through :browser
   
     get "/:provider", AuthController, :request
     get "/:provider/callback", AuthController, :callback
   end

8. You controller needs to implement callbacks to deal with Ueberauth.Auth and Ueberauth.Failure responses.

For an example implementation see the Überauth Example application.

Depending on the configured url you can initial the request through:

/auth/github

Or with options:

/auth/github?scope=user,public_repo

By default the requested scope is "user,public_repo". Scope can be configured either explicitly as a scope query value on the request path or in your configuration:

config :ueberauth, Ueberauth,
  providers: [
    github: {Ueberauth.Strategy.Github, [default_scope: "user,public_repo,notifications"]}
  ]

It is also possible to disable the sending of the redirect_uri to GitHub. This is particularly useful when your production application sits behind a proxy that handles SSL connections. In this case, the redirect_uri sent by Ueberauth will start with http instead of https, and if you configured your GitHub OAuth application's callback URL to use HTTPS, GitHub will throw an uri_missmatch error.

To prevent Ueberauth from sending the redirect_uri, you should add the following to your configuration:

config :ueberauth, Ueberauth,
  providers: [
    github: {Ueberauth.Strategy.Github, [send_redirect_uri: false]}
  ]

Please see LICENSE for licensing details.