RailsJwt

Super easy way to add JWT support for Rails API projects.

This gem makes it super easy to add JWT support in your Rails project. Just a few of quick steps and you are good to go!

Your user model must have an authenticate method (that takes a password as its paramter) implemented. A common and quick way is to use has_secure_password

Alternatively, you can implement your own authenticate method, for example, if you want to authenticate with an LDAP server.

Add this line to your application's Gemfile:

gem 'rails_jwt'

And then execute:

$ bundle

Execute following to add configuration file in config/initializers folder:

$ rails g rails_jwt:install

Add following line in your routes.rb

mount RailsJwt::Engine => "/auth"

Add the following in the controller you would to secure:

include RailsJwt::Authentication
before_action :authenticate_user

Or you can create a secure controller that you can inherit in the all of the controllers you would like to secure:

class SecureController < ApplicationController
    include RailsJwt::Authentication
    before_action :authenticate_user
end

Send a POST request:

POST /auth/login HTTP/1.1
Host: localhost:3000
Content-Type: application/json

{ "user_id": "test@abc.com", "password": "test"}

If authentication is successful, you will get a response like this:

{
    "jwt": "eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOnsiaWQiOjF9LCJleHAiOjE2MTY4Mjg3NTZ9.gUmZaBjUM-FOM-_9T47ul4mM7c_YG8lF9l11MlGUmBM"
}

Pass the returned token to the header of your subsequent API call:

GET /users HTTP/1.1
Host: localhost:3000
Authorization: Bearer eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOnsiaWQiOjF9LCJ1c2VyX2lkIjoxLCJlbWFpbCI6Im1haWxAYWFtaXIucGsiLCJhY3RpdmUiOnRydWUsImV4cCI6MTYxNjc4MjU5M30.-lybW5musgaWS-g1mvTtgmeSM_oi1U7Xa_elh68Ph-c

A number of configuration options are available in initiliazers/rails_jwt.rb file. By default user's email will be used as a login id, however that can be modified by changing relevant entry in rails_jwt.rb config file (config.user_id_attr = :login_id).

By default the payload looks like following:

{
 "sub": {
  "id": 1
 },
 "exp": 1616823684
}

In above payload sub.id is the unique id (primary key) of your user object that will be used to lookup the calling user. If you want to add more fields in the payload, you will need to add jwt_payload method in your user model:

def jwt_payload
    {email: self.email, active: self.active}
end

Addition of above method will create a payload similar to the following:

{
 "sub": {
  "id": 1
 },
 "email": "test@abc.com",
 "active": true,
 "exp": 1616823952
}

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