rake task to export public exercises

lib/tasks/export_public_exercises.rake

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+namespace :export_exercises do
+  desc 'exports all public exercises to codeharbor'
+  task :public, [:codeharbor_link_id] => [:environment] do |_, args|
+    codeharbor_link = CodeharborLink.find(args.codeharbor_link_id)
+
+    Exercise.where(public: true).each do |exercise|
+      puts "Exporting exercise\# #{exercise.id}"
+      error = ExerciseService::PushExternal.call(
+        zip: ProformaService::ExportTask.call(exercise: exercise),
+        codeharbor_link: codeharbor_link
+      )
+      if error.nil?
+        puts "Successfully exported exercise\# #{exercise.id}"
+      else
+        puts "An error occured during export of exercise\# #{exercise.id}: #{error}"
+      end
+    end
+  end
+end