administrator dashboard for observing the Docker container pool

app/assets/javascripts/dashboard.js

@@ -0,0 +1,35 @@
+$(function() {
+  var REFRESH_INTERVAL = 5000;
+
+  var refreshData = function() {
+    var jqxhr = $.ajax({
+      dataType: 'json',
+      method: 'GET'
+    });
+    jqxhr.done(updateView);
+  };
+
+  var updateProgressBar = function(progress_bar, data) {
+    var percentage = Math.round(data.quantity / data.pool_size * 100);
+    progress_bar.attr({
+      'aria-valuemax': data.pool_size,
+      'aria-valuenow': data.quantity,
+      style: 'width: ' + percentage + '%'
+    });
+    progress_bar.html(data.quantity);
+  };
+
+  var updateView = function(response) {
+    _.each(response.docker, function(data) {
+      var row = $('tbody tr[data-id=' + data.id + ']');
+      $('.pool-size', row).html(data.pool_size);
+      var progress_bar = $('.quantity .progress .progress-bar', row);
+      updateProgressBar(progress_bar, data);
+    });
+  };
+
+  if ($.isController('dashboard')) {
+    refreshData();
+    setInterval(refreshData, REFRESH_INTERVAL);
+  }
+});

app/controllers/admin/dashboard_controller.rb

@@ -0,0 +1,17 @@
+module Admin
+  class DashboardController < ApplicationController
+    include DashboardHelper
+
+    def policy_class
+      DashboardPolicy
+    end
+
+    def show
+      authorize(self)
+      respond_to do |format|
+        format.html
+        format.json { render(json: dashboard_data) }
+      end
+    end
+  end
+end

app/helpers/admin/dashboard_helper.rb

@@ -0,0 +1,13 @@
+module Admin
+  module DashboardHelper
+    def dashboard_data
+      {docker: docker_data}
+    end
+
+    def docker_data
+      ExecutionEnvironment.order(:id).select(:id, :permitted_execution_time, :pool_size).map do |execution_environment|
+        execution_environment.attributes.merge(quantity: DockerContainerPool.quantities[execution_environment.id])
+      end
+    end
+  end
+end

app/policies/admin/dashboard_policy.rb

@@ -0,0 +1,4 @@
+module Admin
+  class DashboardPolicy < AdminOnlyPolicy
+  end
+end

app/views/admin/dashboard/show.html.slim

@@ -0,0 +1,20 @@
+h1 = t('breadcrumbs.dashboard.show')
+
+h2 Docker
+
+- if DockerContainerPool.config[:active]
+  .table-responsive
+    table.table
+      thead
+        tr
+          th = t('activerecord.models.execution_environment.one')
+          th = t('activerecord.attributes.execution_environment.pool_size')
+          th = t('.quantity')
+      tbody
+        - ExecutionEnvironment.order(:name).each do |execution_environment|
+          tr data-id=execution_environment.id
+            td = link_to(execution_environment, execution_environment)
+            td.pool-size
+            td.quantity = progress_bar(0)
+- else
+  p = t('.inactive')

config/locales/de.yml

@@ -123,11 +123,18 @@ de:
       models:
         exercise:
           at_most_one_main_file: dürfen höchstens eine Hauptdatei enthalten
+  admin:
+    dashboard:
+      show:
+        inactive: Der Container-Pool ist nicht aktiv.
+        quantity: Verfügbare Container
   application:
     not_authorized: Sie Sind nicht berechtigt, diese Aktion auszuführen.
   breadcrumbs:
     application:
       welcome: Startseite
+    dashboard:
+      show: Dashboard
     sessions:
       destroy_through_lti: Code-Abgabe
   consumers:

config/locales/en.yml

@@ -123,11 +123,18 @@ en:
       models:
         exercise:
           at_most_one_main_file: must include at most one main file
+  admin:
+    dashboard:
+      show:
+        inactive: Container pooling is not enabled.
+        quantity: Available Containers
   application:
     not_authorized: You are not authorized to perform this action.
   breadcrumbs:
     application:
       welcome: Cover Page
+    dashboard:
+      show: Dashboard
     sessions:
       destroy_through_lti: Code Submission
   consumers:

config/routes.rb

@@ -3,6 +3,10 @@ FILENAME_REGEXP = /[\w\.]+/ unless Kernel.const_defined?(:FILENAME_REGEXP)
 Rails.application.routes.draw do
   root to: 'application#welcome'
 
+  namespace :admin do
+    get 'dashboard', to: 'dashboard#show'
+  end
+
   get '/help', to: 'application#help'
 
   resources :consumers

spec/controllers/admin/dashboard_controller_spec.rb

@@ -0,0 +1,21 @@
+require 'rails_helper'
+
+describe Admin::DashboardController do
+  before(:each) { allow(controller).to receive(:current_user).and_return(FactoryGirl.build(:admin)) }
+
+  describe 'GET #show' do
+    describe 'with format HTML' do
+      before(:each) { get :show }
+
+      expect_status(200)
+      expect_template(:show)
+    end
+
+    describe 'with format JSON' do
+      before(:each) { get :show, format: :json }
+
+      expect_json
+      expect_status(200)
+    end
+  end
+end

spec/policies/admin/dashboard_policy_spec.rb

@@ -0,0 +1,19 @@
+require 'rails_helper'
+
+describe Admin::DashboardPolicy do
+  subject { Admin::DashboardPolicy }
+
+  permissions :show? do
+    it 'grants access to admins' do
+      expect(subject).to permit(FactoryGirl.build(:admin), :dashboard)
+    end
+
+    it 'does not grant access to teachers' do
+      expect(subject).not_to permit(FactoryGirl.build(:teacher), :dashboard)
+    end
+
+    it 'does not grant access to external users' do
+      expect(subject).not_to permit(FactoryGirl.build(:external_user), :dashboard)
+    end
+  end
+end