Home » Ruby » Simplified GitHub Login for a Ruby Web App

About Yegor Bugayenko

Yegor Bugayenko
Yegor Bugayenko is an Oracle certified Java architect, CEO of Zerocracy, author of Elegant Objects book series about object-oriented programing, lead architect and founder of Cactoos, Takes, Rultor and Jcabi, and a big fan of test automation.

Simplified GitHub Login for a Ruby Web App

You know what OAuth login is, right? It’s when your users click “login” and get redirected to Facebook, Twitter, Google, or some other website which then identifies them.

Then they go back to your website and you know who they are. It’s very convenient for them.

It’s convenient for you too, since you don’t need to implement the login functionality and don’t need to keep their credentials in a database.

I created a simple Ruby gem to simplify this operation for GitHub only. Here is how it works.

First, you will have to register your application in GitHub, as this page explains. This is how it works with Sinatra, but you can do something similar in any framework.

First, somewhere in the global space, before the app starts:

require 'glogin'
configure do
  set :glogin, GLogin::Auth.new(
    # You get this from GitHub, when you register your
    # web application:
    # Make sure this value is coming from a secure
    # place and is NOT visible in the source code:
    # This is what you will register in GitHub as an
    # authorization callback URL:

Next, for all web pages we need to parse a cookie, if it exists, and convert it into a user:

require 'sinatra/cookies'
before '/*' do
  if cookies[:glogin]
      @user = GLogin::Cookie::Closed.new(
        # This must be some long text to be used to
        # encrypt the value in the cookie:
    rescue OpenSSL::Cipher::CipherError => _
      # Nothing happens here, the user is not logged in.

If the glogin cookie comes in and contains valid data, a local variable @user will be set to something like this:

{ login: 'yegor256', avatar: 'http://...' }

Next, we need a URL for GitHub OAuth callback:

get '/github-callback' do
  cookies[:glogin] = GLogin::Cookie::Open.new(
    # The same encryption secret that we were using above:
  redirect to('/')

Finally, we need a logout URL:

get '/logout' do
  redirect to('/')

One more thing is the login URL you will need for your front page. Here it is:


For unit testing you can just provide an empty string as a secret for GLogin::Cookie::Open and GLogin::Cookie::Closed and the encryption will be disabled: whatever comes from the cookie will be trusted. For testing it will be convenient to provide a user name in a query string, like this:


To enable that, it’s recommended you add this line (see how it works in zold-io/wts.zold.io):

require 'sinatra/cookies'
before '/*' do
  cookies[:glogin] = params[:glogin] if params[:glogin]
  if cookies[:glogin]
    # same as above

I use this gem in sixnines, 0pdd, and Zold web apps on top of Sinatra (all open source).


Published on Web Code Geeks with permission by Yegor Bugayenko, partner at our WCG program. See the original article here: Simplified GitHub Login for a Ruby Web App

Opinions expressed by Web Code Geeks contributors are their own.

(0 rating, 0 votes)
You need to be a registered member to rate this.
Start the discussion Views Tweet it!
Do you want to know how to develop your skillset to become a Web Rockstar?
Subscribe to our newsletter to start Rocking right now!
To get you started we give you our best selling eBooks for FREE!
1. Building web apps with Node.js
2. HTML5 Programming Cookbook
3. CSS Programming Cookbook
4. AngularJS Programming Cookbook
5. jQuery Programming Cookbook
6. Bootstrap Programming Cookbook
and many more ....
I agree to the Terms and Privacy Policy
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments