Aegis - A complete authorization solution for Rails

Aegis is an authorization solution for Ruby on Rails that supports roles and a RESTish, resource-style declaration of permission rules. Getting started with Aegis is easy and requires very little integration. As your authorization requirements become more complex, Aegis will grow with you.

Getting started

All your permissions live in a single class Permissions. Permissions are described using resources, similiar to your routes. Your permission resources can match those in your routes, but don’t have to.

Access to resources or individual actions can be granted or denied to specific roles.

class Permissions < Aegis::Permissions
  role :user
  role :admin
  resources :projects do
    allow :everyone
  end
  resources :users do
    allow :admin
  end
end

To give your user model a role, it needs to have an attribute role_name. The has_role macro wires everything together:

class User < ActiveRecord::Base
  has_role
end

You can now check if a user has permission to access a given action in your controllers and views:

<% if current_user.may_update_project? @project %>
  <%= link_to 'Edit', edit_project_path(@project) %>
<% end %>

You can protect all actions in a controller through an Aegis resource with a single line:

class ProjectsController < ApplicationController
  permissions :projects
end

Further reading

You are now familiar with the basic use case. Aegis can do a lot more than that. There is an awesome documentation wiki with detailed information on many basic and advanced topics, including:

• Defining roles and basic permissions

• Checking permissions

• Giving your user model a role

• Defining permissions with resources

• Controller integration

• Giving default access to superusers

• Distinguishing between reading and writing actions

• Aliasing actions

• Checking permissions when no user is signed in

• Handling denied permissions in your controllers

• Changing behavior when a permission is undefined

• Multiple roles per user

• Testing permissions

• Upgrading to Aegis 2

Installation

Aegis is a gem, which you can install with

sudo gem install aegis

In Rails 2, add the following to your environment.rb:

config.gem 'aegis'

In Rails 3, add the following to your Gemfile:

gem 'aegis'

Rails 3 compatibility

We cannot guarantee Rails 3 compatibility at this point, but we will upgrade the gem when Rails 3 is released.

Credits

Henning Koch, Tobias Kraze

makandra.com

gem-session.com