terms of use/privacy policy endpoints and extension point

this commit adds terms_of_use_url and privacy_policy_url helpers
that can be customized by plugins.  it also provides controller
actions to redirect to these, so that custom URLs can be
computed on demand instead of on every page load

closes CNVS-17882

test plan:
 - without any authentication, /terms_of_use and /privacy_policy
   should redirect to the default documents on canvaslms.com
   (custom documents based on geographic location and account
   license type will come later.)

Change-Id: I72654168d244b5196f841e1a159c14c4c4b29cb3
Reviewed-on: https://gerrit.instructure.com/47331
Reviewed-by: James Williams  <jamesw@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>
QA-Review: Jahnavi Yetukuri <jyetukuri@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>

app/controllers/application_controller.rb

@@ -33,6 +33,7 @@ class ApplicationController < ActionController::Base
   include Api::V1::User
   include Api::V1::WikiPage
   include Lti::MessageHelper
+  include LegalInformationHelper
   around_filter :set_locale
 
   helper :all

app/controllers/legal_information_controller.rb

@@ -0,0 +1,27 @@
+#
+# Copyright (C) 2015 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas 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 Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+class LegalInformationController < ApplicationController
+  def terms_of_use
+    redirect_to terms_of_use_url
+  end
+
+  def privacy_policy
+    redirect_to privacy_policy_url
+  end
+end

app/helpers/legal_information_helper.rb

@@ -0,0 +1,33 @@
+#
+# Copyright (C) 2015 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas 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 Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+module LegalInformationHelper
+  def terms_of_use_url
+    Setting.get('terms_of_use_url', 'http://www.canvaslms.com/policies/terms-of-use')
+  end
+
+  def privacy_policy_url
+    Setting.get('privacy_policy_url', 'http://www.canvaslms.com/policies/privacy-policy')
+  end
+
+protected
+  # extension point
+  def legal_information
+    {}
+  end
+end

config/routes.rb

@@ -757,6 +757,9 @@ CanvasRails::Application.routes.draw do
 
   get 'courses/:course_id/outcome_rollups' => 'outcome_results#rollups', as: 'course_outcome_rollups'
 
+  get 'terms_of_use' => 'legal_information#terms_of_use', as: 'terms_of_use_redirect'
+  get 'privacy_policy' => 'legal_information#privacy_policy', as: 'privacy_policy_redirect'
+
   ### API routes ###
 
   # TODO: api routes can't yet take advantage of concerns for DRYness, because of

spec/controllers/legal_information_controller_spec.rb

@@ -0,0 +1,36 @@
+#
+# Copyright (C) 2015 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas 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 Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')
+
+describe LegalInformationController do
+
+  describe "GET 'terms_of_use'" do
+    it "should redirect to terms_of_use_url, no authorization required" do
+      get 'terms_of_use'
+      expect(response).to redirect_to controller.terms_of_use_url
+    end
+  end
+
+  describe "GET 'privacy_policy'" do
+    it "should redirect to privacy_policy_url, no authorization required" do
+      get 'privacy_policy'
+      expect(response).to redirect_to controller.privacy_policy_url
+    end
+  end
+end