GRN2-211: Added a maintenance mode (#675)

* Added a maintenance mode

* Cleaned up dockerignore file

* Added branding to maintenance page

* Fixed branding

app/controllers/application_controller.rb

@@ -26,10 +26,11 @@ class ApplicationController < ActionController::Base
   # Force SSL for loadbalancer configurations.
   before_action :redirect_to_https
 
+  before_action :set_user_domain
+  before_action :maintenance_mode?
   before_action :migration_error?
   before_action :set_locale
   before_action :check_admin_password
-  before_action :set_user_domain
   before_action :check_user_role
 
   # Manually handle BigBlueButton errors
@@ -45,6 +46,17 @@ class ApplicationController < ActionController::Base
     render :migration_error unless ENV["DB_MIGRATE_FAILED"].blank?
   end
 
+  def maintenance_mode?
+    if ENV["MAINTENANCE_MODE"].present?
+      render "errors/greenlight_error", status: 503, formats: :html,
+        locals: {
+          status_code: 503,
+          message: I18n.t("errors.maintenance.message"),
+          help: I18n.t("errors.maintenance.help"),
+        }
+    end
+  end
+
   # Sets the appropriate locale.
   def set_locale
     update_locale(current_user)
@@ -140,6 +152,9 @@ class ApplicationController < ActionController::Base
       begin
         retrieve_provider_info(@user_domain, 'api2', 'getUserGreenlightCredentials')
       rescue => e
+        # Use the default site settings
+        @user_domain = "greenlight"
+
         if e.message.eql? "No user with that id exists"
           render "errors/greenlight_error", locals: { message: I18n.t("errors.not_found.user_not_found.message"),
             help: I18n.t("errors.not_found.user_not_found.help") }

app/controllers/themes_controller.rb

@@ -17,6 +17,7 @@
 # with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
 
 class ThemesController < ApplicationController
+  skip_before_action :maintenance_mode?
   before_action :provider_settings
 
   # GET /primary