added the ability to limit memory consumption of code submissions executed using Docker

app/controllers/execution_environments_controller.rb

@@ -29,7 +29,7 @@ class ExecutionEnvironmentsController < ApplicationController
   end
 
   def execution_environment_params
-    params[:execution_environment].permit(:docker_image, :exposed_ports, :editor_mode, :file_extension, :file_type_id, :help, :indent_size, :name, :permitted_execution_time, :pool_size, :run_command, :test_command, :testing_framework).merge(user_id: current_user.id, user_type: current_user.class.name)
+    params[:execution_environment].permit(:docker_image, :exposed_ports, :editor_mode, :file_extension, :file_type_id, :help, :indent_size, :memory_limit, :name, :permitted_execution_time, :pool_size, :run_command, :test_command, :testing_framework).merge(user_id: current_user.id, user_type: current_user.class.name)
   end
   private :execution_environment_params
 

app/models/execution_environment.rb

@@ -15,6 +15,7 @@ class ExecutionEnvironment < ActiveRecord::Base
   validate :valid_test_setup?
   validate :working_docker_image?, if: :validate_docker_image?
   validates :docker_image, presence: true
+  validates :memory_limit, numericality: {greater_than_or_equal_to: DockerClient::MINIMUM_MEMORY_LIMIT, only_integer: true}, presence: true
   validates :name, presence: true
   validates :permitted_execution_time, numericality: {only_integer: true}, presence: true
   validates :pool_size, numericality: {only_integer: true}, presence: true

app/views/execution_environments/_form.html.slim

@@ -17,6 +17,9 @@
     = f.label(:exposed_ports)
     = f.text_field(:exposed_ports, class: 'form-control', placeholder: '3000, 4000')
     .help-block == t('.hints.exposed_ports')
+  .form-group
+    = f.label(:memory_limit)
+    = f.number_field(:memory_limit, class: 'form-control', min: DockerClient::MINIMUM_MEMORY_LIMIT, value: f.object.memory_limit || DockerClient::DEFAULT_MEMORY_LIMIT)
   .form-group
     = f.label(:permitted_execution_time)
     = f.number_field(:permitted_execution_time, class: 'form-control', min: 1)

app/views/execution_environments/show.html.slim

@@ -5,7 +5,7 @@ h1
 = row(label: 'execution_environment.name', value: @execution_environment.name)
 = row(label: 'execution_environment.user', value: link_to(@execution_environment.author, @execution_environment.author))
 = row(label: 'execution_environment.file_type', value: @execution_environment.file_type.present? ? link_to(@execution_environment.file_type, @execution_environment.file_type) : nil)
-- [:docker_image, :exposed_ports, :permitted_execution_time, :pool_size, :run_command, :test_command].each do |attribute|
+- [:docker_image, :exposed_ports, :memory_limit, :permitted_execution_time, :pool_size, :run_command, :test_command].each do |attribute|
   = row(label: "execution_environment.#{attribute}", value: @execution_environment.send(attribute))
 = row(label: 'execution_environment.testing_framework', value: @testing_framework_adapter.try(:framework_name))
 = row(label: 'execution_environment.help', value: render_markdown(@execution_environment.help))