Arvados

h1. Workbench authentication process

# When the user goes to workbench, it checks for a session or @?api_token=xxx@ in the URL for the API token.  If no API token is found, the user is directed to the workbench "welcome" page.

# The "welcome" page has a "log in" button that directs the user to the API server login URL, with a @?return_to=xxx@ link embedded in the URL.

# The 'login' endpoint goes to @UserSessionsController#login@ in the API server.  This redirects to @/auth/joshid?return_to=xxx@

# @/auth/joshid@ is intercepted by the "OmniAuth":https://github.com/intridea/omniauth Rack middleware and invokes the @josh_id@ OmniAuth strategy.

** The @josh_id@ OmniAuth strategy is implemented in @arvados/services/api/lib/josh_id.rb@ and is a subclass of @OmniAuth::Strategies::OAuth2@

# OmniAuth starts the "request_phase" of @OmniAuth::Strategies::OAuth2@.  This redirects to @#{options[:custom_provider_url]}/auth/josh_id/authorize@ using CUSTOM_PROVIDER_URL defined in @arvados/services/api/config/initializers/omniauth.rb@

# In the sso-provider, @/auth/josh_id@ is routed to @AuthController#authorize@, and is intercepted by @before_filter :authenticate_user!@ (part of the "devise gem":https://github.com/plataformatec/devise)

** devise is configured at @sso-provider/config/initializers/devise.rb@

** @authenticate_user!@ is not explicitly defined but instead monkey patched into the controller in @devise/lib/devise/controllers/helper.rb@

** @authenticate_user!@ calls @warden.authenticate!@ where "warden":https://github.com/hassox/warden is yet another Rack authentication gem

** @devise :omniauthable, :omniauth_providers => [:google]@ configures @sso-provider/app/models/user.rb@

# @AuthController#authorize@ creates an AccessGrant

h2. Questions

* What is workbench's "secret_token" for?