# warden-github-rails

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A gem for rails that provides easy GitHub OAuth integration.
It is built on top of [warden-github](https://github.com/atmos/warden-github), which gives you an easy to use [warden](https://github.com/hassox/warden) strategy to authenticate GitHub users.

## Motivation

**Wouldn't it be nice to**

- use your organization and its teams for user access control?
- add a new employee to your GitHub organization or team in order to grant them access to your app's admin area?

The motivation for this gem was to provide a very easy authorization (not authentication) mechanism to existing rails apps for admins, especially in combination with organization and team memberships.
The provided routing helpers do exactly that.
They allow you to restrict access to members of your organization or a certain team.

This is how your rails `routes.rb` could look like:

```ruby
constraints(subdomain: 'admin') do
  github_authenticate(org: 'my_company_inc') do
    resources :users
    resources :projects

    github_authenticated(team: 'sysadmins') do
      resource :infrastructure
    end
  end
end
```

Of course, this gem can also be used for user registration and authentication.
Several helper methods are available in the controller to accomplish this:

```ruby
class UsersController < ApplicationController
  # ...

  def new
    github_authenticate! # Performs OAuth flow when not logged in.
    @user = User.new(name: github_user.name, email: github_user.email)
  end

  def create
    attrs = params.require(:user).permit(:name, :email).merge(github_id: github_user.id)
    @user = User.create(attrs)

    if @user.persisted?
      redirect_to :show
    else
      render :new
    end
  end

  # ...
end
```

## Example App

This repository includes an example app in [example/](example/).
To play with it, follow these steps:

1.  [Create an OAuth application in your GitHub settings](https://github.com/settings/applications/new).
    Set the callback URL to `http://localhost:3000/`

2.  Check out this repo and run:

    ```
    $ bundle
    $ cd example
    $ GITHUB_CLIENT_ID=your_id_from_step1 GITHUB_CLIENT_SECRET=your_secret_from_step1 bundle exec rails s
    ```

3.  Point your browser to [http://localhost:3000/](http://localhost:3000/) and enjoy!

## Installation

To use this gem, add it to your `Gemfile`:

```ruby
gem 'warden-github-rails'
```

If you're using devise, make sure to use version 2.2.4 or newer.
Previous versions are not compatible with warden-github-rails and thus will not work.
See the note at [*Using alongside Devise and other Warden Gems*](#using-alongside-devise-and-other-warden-gems) for an explanation.

## Usage

### Configuration

First off, you might want to configure this gem by creating an initializer such as `config/initializers/warden_github_rails.rb`.
There you can define:

- various scopes and their configs (scopes are types of users with different configs)
- the default scope (which is `:user` by default)
- team aliases (GitHub teams are identified by a numerical ID; defining an alias for a team makes it easier to use)

Here's how such a config might look like:

```ruby
Warden::GitHub::Rails.setup do |config|
  config.add_scope :user,  client_id:     'foo',
                           client_secret: 'bar',
                           scope:         'user:email'

  config.add_scope :admin, client_id:     'abc',
                           client_secret: 'xyz',
                           redirect_uri:  '/admin/login/callback',
                           scope:         'read:org'

  config.default_scope = :admin

  config.add_team :marketing, 456
end
```

For a list of allowed config parameters to use in `#add_scope`, read the [warden-github documentation](https://github.com/atmos/warden-github#parameters).

### Inside `routes.rb`

The available routing helpers are defined and documented in [lib/warden/github/rails/routes.rb](lib/warden/github/rails/routes.rb).
They all accept an optional scope that, when omitted, falls back to the default_scope configured in the initializer.

Examples:

```ruby
# Performs login if not logged in already.
github_authenticate do
  resource :profile
end

# Does not perform login when not logged in.
github_authenticated do
  delete '/logout' => 'sessions#delete'
end

# Only matches when not logged in. Does not perform login.
github_unauthenticated do
  resource :registration
end

# Only matches when member of the organization. Initiates login if not logged in.
github_authenticate(org: 'my_company') do
  resource :admin
end

# Only matches when member of the team. Does not initiate login if not logged in.
github_authenticated(team: 'markting') do
  get '/dashboard' => 'dashboard#show'
end

# Matches if a member of any of the teams given. Does not initiate login if not logged in.
github_authenticated(team: ['markting', 'graphic-design']) do
  get '/dashboard' => 'dashboard#show'
end

# Using dynamic membership values:
github_authenticate(org: lambda { |req| req.params[:id] }) do
  get '/orgs/:id' => 'orgs#show'
end
```

### Inside a Controller

The available controller helpers are defined and documented in [lib/warden/github/rails/controller_helpers.rb](lib/warden/github/rails/controller_helpers.rb).
They all accept an optional scope that, when omitted, falls back to the default_scope configured in the initializer.

```ruby
class SomeController < ActionController::Base
  def show
    @is_admin = github_authenticated?(:admin)
  end

  def delete
    github_logout
    redirect_to '/'
  end

  def settings
    github_authenticate!
    @settings = UserSettings.find_by(github_user_id: github_user.id)
  end

  def finish_wizard
    github_session[:wizard_completed] = true
  end

  def followers
    @followers = github_user.api.followers
  end
end
```

### Communicating with the GitHub API

Once a user is logged in, you'll have access to it in the controller using `github_user`.
It is an instance of `Warden::GitHub::User` which is defined in the [warden-github](https://github.com/atmos/warden-github/blob/master/lib/warden/github/user.rb) gem.
The instance has several methods to access user information such as `#name`, `#id`, `#email`, etc.
It also features a method `#api` which returns a preconfigured [Octokit](https://github.com/octokit/octokit.rb) client for that user.

### Test Helpers

This gems comes with a couple test helpers to make your life easier:

-   A method is added to `Rack::Response` called `#github_oauth_redirect?` which
    returns true if the response is a redirect to a url that starts with
    `https://github.com/login/oauth/authorize`. You can use it in your request
    tests to make sure the OAuth dance is initiated. In rspec you could verify
    this as follows:

    ```ruby
    subject { get '/some-url-that-triggers-oauth' }
    it { is_expected.to be_github_oauth_redirect }
    ```

-   A mock user that allows you to stub team and organization memberships:

    ```ruby
    user = Warden::GitHub::Rails::TestHelpers::MockUser.new
    user.stub_membership(team: [234, 987], org: 'some-inc')
    user.team_member?(234) # => true
    user.organization_member?('rails') # => false
    ```

-   A method that creates a mock user and logs it in. If desired, the scope can
    be specified. The method returns the mock user so that you can manipulate it
    further:

    ```ruby
    user = github_login(:admin)

    get '/org/rails/admin'
    expect(response).to be_not_found

    user.stub_membership(org: 'rails')
    get '/org/rails/admin'
    expect(response).to be_ok
    ```

In order to use the mock user and the `#github_login` method, make sure to `require 'warden/github/rails/test_helpers'` and to `include Warden::GitHub::Rails::TestHelpers` in your tests.

## Using alongside Devise and other Warden Gems

Currently this gem does not play nicely with other gems that setup a warden middleware.
The reason is that warden simply does not have support for multiple middlewares.
The warden middleware configures a warden instance and adds it to the rack environment.
Any other warden middleware downstream checks for any existing warden instance in the environment and, if present, skips itself.
I've opened an [issue](https://github.com/hassox/warden/issues/67) on the warden repository to discuss possible workarounds.

Nevertheless, this gem is compatible with devise for version 2.2.4 and newer.
devise allows you to specify a block that will be invoked when the warden middleware is configured.
This functionality is used in this gem in order to setup the github strategy for warden instead of inserting our own middleware.

## Additional Information

### Dependencies

- [warden-github](https://github.com/atmos/warden-github)
    - [warden](https://github.com/hassox/warden)
    - [octokit](https://github.com/octokit/octokit.rb)

### Author

Philipe Fatio ([@fphilipe][fphilipe twitter])

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### License

MIT License. Copyright 2013 Philipe Fatio

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