Chris Mendez in For Developers, Ruby

Rails: Authenticating with Devise

I've been working with the Stripe API lately and I thought it might be handy to write a simple Ruby on Rails application that integrates Ruby on Rails, Devise and Stripe.

Step 1 - Setting up your Environment

First things first, you need to make sure you've installed Homebrew

Upgrading Ruby and installing Rails

There are two ways to upgrade Ruby on Mac and the differences are so subtle that they really only matter to the most dogmatic of Rubyists. Rather than split hairs, just pick one:

Finishing Touches

A proper Rails app generally requires a database such as MongoDB, MySQL, or PostgreSQL. If homebrew in installed on your computer, follow these 4 simple steps to help you install a database

Step 2 - Create a new rails app

Create your new app and use postgres for a database.

rails new name_of_app -d postgresql

Through Terminal, change into your web app.

cd /path/to/name_of_app

Install any pre-existing gem into your rails app.

bundle install

Create the database

rails db:create

Step 3 - Install Devise gem

Install Devise

Open up your Gemfile and add the devise gem.

# Devise Authentication for Rails 5
gem 'devise', git: ''

Run the bundle command to install devise

rails g devise:install

Configure Devise

Once you run the bundle command, you'll see that devise provides you with a set of instructions. I suggest you follow the steps.


  • If you're using Rails 5 API mode, you don't need to complete items #3 and #4.

Create the Devise Model

Now that you've installed devise, it's time to create a user model.

rails g devise user

Once you've created your model, update the datbase.

rails db:migrate

Create a controller

Create a home controller with a view named "index".

rails g controller home index

Tweak the controller

Add this code fragment to /app/controllers/home_controller.rb. This allows you authenticate a user before anything is accessed or changed.

class HomeController < ApplicationController
   before_filter :authenticate_user!

Start your server

rails s

Review your work

Now that you've created a model and upgraded your database, you can now run your rails server and test out the app with the links below.

These links are auto created by Devise.

http://localhost:3000/users/sign_up => new_user_session

http://localhost:3000/users/sign_in => destroy_user_session

http://localhost:3000/users/password/new => new_user_registration

Customizing Devise

Your UIX designer is very likely going to want to brand your app and change the design of the log-in views. All you need to do is tell Devise to generate the views so that you can modify them.

Custom Views

rails g devise:views

Custom Login

If your Dir of Product prefers your users to log-in using a username instead of an e-mail address, you can easily make that change by modifying the User model. Here's how to replace e-mail with username.

rails g migration add_username_to_users username:string

Now update your database.

rails db:migrate

Then modify devise config/initializers/devise.rb and add this:

Devise.setup do |config|
config.authentication_keys   = [:username]
config.case_insensitive_keys = [:username]
config.strip_whitespace_keys = [:username]

The final step is update the view to accomodate for username app/views/devise/sessions/new.html.erb

<h2>Sign in</h2>
<%= form_for(resource, :as => resource_name, :url => session_ path(resource_name)) do |f| %>
<div><%= f.label :username %><br />

<%= f.text_field :username, :autofocus => true %><div>

Email Confirmation

If you want users to confirm their registration through e-mail, here's how:

Step 1

Modify config/environments/development.rb

#config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }

config.action_mailer.delivery_method = :smtp
config.action_mailer.perform_deliveries = true
config.action_mailer.raise_delivery_errors = true
config.action_mailer.smtp_settings = {
     :address => "",
     #:port => 587,
     :domain => "",
     :user_name => "my_username",
     :password => "S0M3P@Sswd",
     :authentication => 'plain',
     :enable_starttls_auto => true

Step 2

Add :confirmable to app/models/user.rb

class User < ApplicationRecord
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable, :confirmable

Step 3

Modify your database

rails g migration add_confirmable_to_users unconfirmed_email:string confirmation_token:token:unique:index confirmed_at:string confirmation_sent_at:datetime password_reset_token:token

Then add this to your newly minted migration file in app/db/migrate/your_db_migration.rb

#your current data will be treated as if they have confirmed their account
User.update_all(:confirmed_at => 


The Rails convention is to use helpers to streamline your code. Here are a few methods Devise offers out of the box.

You can ask your user to authenticate before they gain access to any controller.


Verify if a user is signed in.


Refer to the current_user.


Access the user's session.



Everything else you might possibly need can found from the authors of Devise.