CASA On Rails

This application is a simple, easy-to-use app store that presents an storefront for finding and selecting apps, implements the Community App Sharing Architecture protocol, provides a mobile app dashboard using Web Storage, and supports integration with learning management systems through LTI Content-Item.

This application is under development and not intended for production use at this time.

CASA

Protocol

The Community App Sharing Architecture (CASA) provides a mechanism for discovering and sharing metadata about web resources such as websites, mobile apps and LTI tools. It models real-world decision-making through extensible attributes, filter and transform operations, flexible peering relationships, etc.

Integration

From the storefront, several different mechanisms are available:

1. Launch the application directly
2. Reply to an LTI Consumer with the ContentItemSelectionResponse message
3. Add to Web Storage and present as a mobile dashboard

Additionally, CASA endpoints are exposed for:

• Local outlets via the CASA Local module
• Adjacent peers via the CASA Publisher module

Application

This application provides the following:

• A basic app store with apps and categories
• Browse categories and search by string for list of apps
• View details about and launch an app
• App submission by authenticated users
• Administer apps, categories, inbound peers and users
• Publish apps to outbound peers
• Receive apps from inbound peers with translation and squashing
• Relay apps received from inbound peers to outbound peers
• Provide apps to local outlets
• Provide apps via LTI ContentItemSelectionResponse message
• Provide apps via a mobile dashboard back by Web Storage

Additional features are planned:

• Filter and transform apps received from inbound peers and before sharing with outbound peers
• Mapping of inbound categories and tags to local categories
• Definition of authorization requirements for local outlets and outbound adjacent peers
• Journaling of changes to propagating apps

References

This application is a reduced and opinionated implementation of CASA. For a more overarching (but also more complex and challenging) implementation, the CASA reference implementation may be useful. A series of gems were developed during the process of building this reference implementation, and they may be useful in some contexts as well.

Configuration

The Basic steps below must be run prior to database migration and seeding, or your default site will not be created!

Basic

Set your CASA engine UUID and user contact information in your environment configuration file, such as:

Rails.application.configure do

  # ..

  # Community App Sharing Architecture configuration
  config.casa = {
    :engine => {
      :uuid => 'dd8c99e2-fe5b-4911-a815-73c17b46d3fc'
    }
  }

  # Local configuration
  config.store = {
    :user_contact => { :name => 'John Doe', :email => 'admin@example.edu' }
  }

  # ..

end

Shibboleth Login via OAuth2 Bridge

This application supports Shibboleth login via the Shibboleth-OAuth2 Bridge by Eric Bollens.

Once the bridge is installed on your web server, add the following to your environment configuration:

Rails.application.configure do

  # ..

  config.oauth2 = {
      :provider => {
          :shibboleth => {
              :enabled => true,
              :key => 'demo',
              :secret => 'secret',
              :properties => {
                  :site => 'http://auth.example.edu',
                  :authorize_url => '/oauth2/authorize',
                  :token_url => '/oauth2/access_token'
              },
              :routes => {
                  :get_user => '/oauth2/user'
              },
              :restrict_to => {
                  :eduPersonPrincipalName => [
                    # users by eduPersonPrincipalName that are allowed to submit apps
                  ],
                  :eduPersonScopedAffiliation => [
                    # eduPersonScopedAffiliations that are allowed to submit apps
                    'employee@ucla.edu'
                  ]
              }
          }
      }
  }

  config.login_route = [:session_oauth2_launch_url, :shibboleth]

  # ..

end

This configuration makes it possible for users with the employee@ucla.edu eduPersonAffiliation to log in and submit applications for review.

Setup

System Dependencies

• Ruby 2.1+
• Java 1.6+
• MySQL 5.0+, PostgreSQL 8.4+ and SQLite 3.6.16+ *
• ElasticSearch 1.0+

*To use a database besides MySQL, update Gemfile accordingly

Manged Dependencies

For Ruby packages:

bundle

Build Web Assets

To build web assets:

RAILS_ENV=production bin/rake assets:clean
RAILS_ENV=production bin/rake assets:precompile

Configure Rails App

See:

• config/database.yml to set the database configuration
• config/environments/*.rb to set the config.casa and config.store variables

Setup Database

bundle exec bin/rake db:migrate
bundle exec bin/rake db:seed

Usage

CASA on Rails is a standard Rails server. Once you ensure that the database and Elasticsearch are running, start it as you'd usually start a Rails server.

If you seeded the database, the default credentials are:

Username: admin
Password: password

Docker Container

CASA on Rails now has a docker container to facilitate getting started developing or testing the project. Visit the docker hub page for more details.

License

CASA On Rails is open-source and licensed under the AFFERO GENERAL PUBLIC LICENSE. The full text of the license may be found in the LICENSE file.