LTI-279: use params from broker for room handler if specified

app/controllers/concerns/bbb_helper.rb

@@ -182,13 +182,13 @@ def wait_for_mod?
   # Return the number of participants in a meeting for the current room.
   def participant_count
     info = meeting_info
-    return info[:participantCount] if info[:returncode] == 'SUCCESS'
+    info[:participantCount] if info[:returncode] == 'SUCCESS'
   end
 
   # Return the meeting start time for the current room.
   def meeting_start_time
     info = meeting_info
-    return info[:startTime] if info[:returncode] == 'SUCCESS'
+    info[:startTime] if info[:returncode] == 'SUCCESS'
   end
 
   def bigbluebutton_moderator_roles

app/controllers/concerns/broker_helper.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+# BigBlueButton open source conferencing system - http://www.bigbluebutton.org/.
+# Copyright (c) 2018 BigBlueButton Inc. and by respective authors (see below).
+# This program is free software; you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free Software
+# Foundation; either version 3.0 of the License, or (at your option) any later
+# version.
+# BigBlueButton is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public License along
+# with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
+
+module BrokerHelper
+  extend ActiveSupport::Concern
+
+  include OmniauthHelper
+
+  # Fetch tenant settings from the broker
+  def tenant_settings(options = {})
+    tenant = options[:tenant] || @room&.tenant || ''
+    Rails.cache.fetch("rooms/tenant_settings/#{tenant}", expires_in: 1.hour) do
+      bbbltibroker_url = omniauth_bbbltibroker_url("/api/v1/tenants/#{tenant}")
+      get_response = RestClient.get(bbbltibroker_url, 'Authorization' => "Bearer #{omniauth_client_token(omniauth_bbbltibroker_url)}")
+
+      JSON.parse(get_response)
+    end
+  rescue StandardError => e
+    Rails.logger.error("Could not fetch tenant credentials from broker. Error message: #{e}")
+    nil
+  end
+
+  # Fetch the params to use when creating the room handler
+  def handler_params(tenant)
+    tenant_settings(tenant: tenant)&.[]('settings')&.[]('handler_params')&.split(',')
+  end
+end

app/controllers/rooms_controller.rb

@@ -29,6 +29,7 @@ class RoomsController < ApplicationController
   # Include concerns.
   include BbbHelper
   include OmniauthHelper
+  include BrokerHelper
 
   before_action :print_parameters if Rails.configuration.developer_mode_enabled
   before_action :authenticate_user!, except: %i[meeting_close], raise: false
@@ -296,7 +297,7 @@ def set_launch
   end
 
   def launch_room(launch_params, tenant)
-    handler = Digest::SHA1.hexdigest("rooms#{tenant}#{launch_params['resource_link_id']}")
+    handler = room_handler(launch_params, tenant)
     handler_legacy = launch_params['custom_params']['custom_handler_legacy'].presence
 
     ## Any launch.
@@ -427,4 +428,19 @@ def set_current_locale
 
     response.set_header('Content-Language', I18n.locale)
   end
+
+  # Generate room handler based on the settings pulled from the broker
+  def room_handler(launch_params, tenant)
+    input = "rooms#{tenant}"
+
+    # use resource_link_id as the default param if nothing was specified in the broker settings
+    room_handler_params = handler_params(tenant).presence || ['resource_link_id']
+
+    room_handler_params.each do |param|
+      param_val = launch_params[param]
+      input += param_val.to_s if param_val
+    end
+
+    Digest::SHA1.hexdigest(input)
+  end
 end