warden-github-rails

A gem for rails that provides easy GitHub OAuth integration.
It is built on top of warden-github, which gives you an easy to use 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:

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:

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/.
To play with it, follow these steps:

1. Create an OAuth application in your GitHub settings.
   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/ and enjoy!

Installation

To use this gem, add it to your Gemfile:

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 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:

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.

Inside routes.rb

The available routing helpers are defined and documented in 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:

# 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.
They all accept an optional scope that, when omitted, falls back to the default_scope configured in the initializer.

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 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 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:

  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:

  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:

  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 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
  • warden
  • octokit

Author

Philipe Fatio (@fphilipe)

License

MIT License. Copyright 2013 Philipe Fatio