Add root account association to external tools

Refs PLAT-4483

Test Plan:
Run migrations and verify you can set the
root_account association of a context external
tool

Change-Id: I77ead138f7e589f8a590536807e730140dfdebf9
Reviewed-on: https://gerrit.instructure.com/193854
Reviewed-by: Marc Phillips <mphillips@instructure.com>
Reviewed-by: Rob Orton <rob@instructure.com>
Reviewed-by: Drake Harper <dharper@instructure.com>
Tested-by: Jenkins
Product-Review: Marc Phillips <mphillips@instructure.com>
QA-Review: Marc Phillips <mphillips@instructure.com>

app/models/context_external_tool.rb

@@ -24,6 +24,7 @@ class ContextExternalTool < ActiveRecord::Base
 
   belongs_to :context, polymorphic: [:course, :account]
   belongs_to :developer_key
+  belongs_to :root_account, class_name: 'Account'
 
   include MasterCourses::Restrictor
   restrict_columns :content, [:name, :description]

db/migrate/20190515205026_add_root_account_id_to_context_external_tools.rb

@@ -0,0 +1,27 @@
+#
+# Copyright (C) 2019 - present 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 AddRootAccountIdToContextExternalTools < ActiveRecord::Migration[5.1]
+  tag :predeploy
+  disable_ddl_transaction!
+
+  def change
+    add_column :context_external_tools, :root_account_id, :integer, limit: 8
+    add_index :context_external_tools, :root_account_id, algorithm: :concurrently
+  end
+end

spec/models/context_external_tool_spec.rb

@@ -35,13 +35,18 @@ describe ContextExternalTool do
         shared_secret: 'secret',
         name: 'test tool',
         url: 'http://www.tool.com/launch',
-        developer_key: developer_key
+        developer_key: developer_key,
+        root_account: @root_account
       )
     end
 
     it 'allows setting the developer key' do
       expect(tool.developer_key).to eq developer_key
     end
+
+    it 'allows setting the root account' do
+      expect(tool.root_account).to eq @root_account
+    end
   end
 
   describe '#login_or_launch_url' do