LinkedIn Sign-In for Rails

This gem enables you to add LinkedIn sign-in functionality to your Rails app. With it, users can sign up for and sign in to your service using their LinkedIn accounts. This gem is highly inspired by google_sign_in, and its configuration and usage are very similar.

Add this line to your application's Gemfile:

gem 'linkedin_openid_sign_in'

And then execute:

$ bundle

Or install it yourself as:

$ gem install linkedin_openid_sign_in

Setup you LinkedIn app and get OAuth credentials

1. Go to LinkedIn Developer Console

2. Click "Create App" button on the top right corner

3. Enter app name

4. You need LinkedIn page, you can add existing page or create new one here. Page admin will have to accept your app.

5. Add logo

6. Click "Create App" button

7. ⚠️IMPORTANT: Page admin will have to accept your app. You can check status on the top of the page.

8. Click "Auth" tab

9. Add "Authorized redirect URLs" (e.g. http://localhost:3000/linkedin_openid_sign_in/callbacks#show)

   This gem use /linkedin_openid_sign_in/callbacks path as callback path and then redirect to provided redirect_url option

10. Click "Save" button

11. Copy "Client ID" and "Client Secret" and add to your Rails app credentials ex.: EDITOR='code --wait' rails credentials:edit

linkedin_sign_in:
  client_id: [Your client ID here]
  client_secret: [Your client secret here]

<%= link_to 'Linkedin login', linkedin_openid_sign_in.sign_in_path(redirect_url: create_login_url) %>

You can adjust redirect_url to your needs. It will be called after successful login.

# config/routes.rb
Rails.application.routes.draw do
  # ...
  get 'login/create', to: 'logins#create', as: :create_login
end

# app/controllers/logins_controller.rb
class LoginsController < ApplicationController
  def create
    if user = authenticate_with_google
      cookies.signed[:user_id] = user.id
      redirect_to user
    else
      redirect_to new_session_url, alert: 'authentication_failed'
    end
  end

  private
    def authenticate_with_google
      if sub = flash[:linkedin_sign_in]['sub']
        User.find_by linkedin_id: sub
      elsif flash[:linkedin_sign_in]
        nil
      end
    end
end

Response is stored in flash[:linkedin_sign_in] and contains following keys:

    {
        'iss': 'https://www.linkedin.com',
        'aud': 'aud',
        'iat': 1700919389,
        'exp': 1700919389,
        'sub': 'sub',
        'email': 'btolarz@gmail.com',
        'email_verified': true,
        'locale': 'en_US'
    }

Check details on https://learn.microsoft.com/en-us/linkedin/consumer/integrations/self-serve/sign-in-with-linkedin-v2?context=linkedin%2Fconsumer%2Fcontext#id-token-payload

1. InvalidState - raised when returned state is different than stored state
2. Error from linkedIn - returned in flash[:linkedin_sign_in][:error] and flash[:linkedin_sign_in][:error_description] ex.: user_cancelled_login

The gem is available as open source under the terms of the MIT License.