Add button to suspend worker

app/controllers/kuroko2/workers_controller.rb

@@ -1,5 +1,22 @@
 class Kuroko2::WorkersController < Kuroko2::ApplicationController
+  before_action :set_worker, only: %i(update)
+
   def index
     @workers = Kuroko2::Worker.ordered.all
   end
+
+  def update
+    @worker.update_attributes(worker_params)
+    redirect_to workers_path
+  end
+
+  private
+
+  def set_worker
+    @worker = Kuroko2::Worker.find(params[:id])
+  end
+
+  def worker_params
+    params.permit(:suspended)
+  end
 end

app/views/kuroko2/workers/index.html.slim

@@ -13,15 +13,18 @@
           th.col-md-1 WID
           th.col-md-2 Queue
           th.col-md-1 Status
-          th.col-md-5 Execution
+          th.col-md-4 Execution
+          th.col-md-1  
           th.col-md-1  
         - for worker in @workers
           tr
             td= worker.hostname
             td= worker.worker_id
             td= worker.queue
             td
-              - if worker.working
+              - if worker.suspended
+                span.label.label-warning SUSPENDED
+              - elsif worker.working
                 span.label.label-primary WORKING
               - else
                 ' 
@@ -39,3 +42,22 @@
                           role: 'button', class: 'btn btn-sm btn-default')
               - else
                 ' 
+            td
+              - if !worker.suspendable
+                ' 
+              - elsif !worker.suspended
+                = button_to('Suspend',
+                            worker_path(worker),
+                            method: :patch,
+                            params: { suspended: true },
+                            role: 'button',
+                            class: 'btn btn-xs btn-default',
+                            data: { confirm: 'Continue suspending the worker? If not, use "Cancel" button.' })
+              - else
+                = button_to('Unsuspend',
+                            worker_path(worker),
+                            method: :patch,
+                            params: { suspended: false },
+                            role: 'button',
+                            class: 'btn btn-xs btn-default',
+                            data: { confirm: 'Continue unsuspending the worker? If not, use "Cancel" button.' })

config/routes.rb

@@ -22,7 +22,7 @@
     get 'page/:page', action: :index, on: :collection, as: 'paged'
   end
 
-  resources :workers, only: :index
+  resources :workers, only: %i(index update)
   resources :job_instances, path: 'instances', only: %w() do
     get :working, action: :working, on: :collection
   end

db/migrate/031_add_suspended_to_workers.rb

@@ -0,0 +1,6 @@
+class AddSuspendedToWorkers < ActiveRecord::Migration[5.0]
+  def change
+    add_column :workers, :suspendable, :boolean, default: false, null: false, after: :execution_id
+    add_column :workers, :suspended, :boolean, default: false, null: false, after: :suspendable
+  end
+end

lib/autoload/kuroko2/command/executor.rb

@@ -19,7 +19,8 @@ def initialize
                    elsif worker_id == (Command::Executor.num_workers - 1)
                      Command::Monitor.new(hostname: @hostname, worker_id: worker_id)
                    else
-                     @worker = Worker.where(hostname: @hostname, worker_id: worker_id, queue: @queue).first_or_create!
+                     @worker = Worker.where(hostname: @hostname, worker_id: worker_id, queue: @queue).first_or_initialize!
+                     @worker.update_column(:suspendable, true)
                      Command::Shell.new(hostname: @hostname, worker_id: worker_id, worker: @worker, queue: @queue)
                    end
       end

lib/autoload/kuroko2/command/shell.rb

@@ -14,6 +14,7 @@ def initialize(hostname:, worker_id: 0, worker:, queue: Execution::DEFAULT_QUEUE
 
       def execute
         @worker.reload
+        return nil if @worker.suspended?
         unless @worker.execution_id?
           if (execution = Execution.poll(@queue))
             do_execute(execution)

spec/command/shell_spec.rb

@@ -62,6 +62,16 @@ module Kuroko2::Command
         end
       end
 
+      context 'when all workers are suspended' do
+        let(:worker) { create(:worker, suspended: true) }
+
+        it 'skips execution' do
+          is_expected.to be_nil
+          execution.reload
+          expect(execution.started_at).to be_nil
+        end
+      end
+
       describe 'memory expectancy calculation' do
         let(:worker) { create(:worker) }
         let(:memory_expectancy) { execution.job_definition.memory_expectancy }

spec/controllers/workers_controller_spec.rb

@@ -2,4 +2,18 @@
 
 RSpec.describe Kuroko2::WorkersController, :type => :controller do
   routes { Kuroko2::Engine.routes }
+
+  before { sign_in }
+
+  let(:worker) { create(:worker) }
+
+  describe '#update' do
+    subject! { patch :update, params: { id: worker.id, suspended: true } }
+
+    it do
+      expect(response).to redirect_to(workers_path)
+
+      expect(assigns(:worker).suspended).to be_truthy
+    end
+  end
 end

spec/dummy/db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 30) do
+ActiveRecord::Schema.define(version: 31) do
 
   create_table "admin_assignments", id: :integer, force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4" do |t|
     t.integer "user_id", null: false
@@ -196,6 +196,8 @@
     t.string "queue", limit: 180, default: "@default", null: false
     t.boolean "working", default: false, null: false
     t.integer "execution_id"
+    t.boolean "suspendable", default: false, null: false
+    t.boolean "suspended", default: false, null: false
     t.datetime "created_at"
     t.datetime "updated_at"
     t.index ["hostname", "worker_id"], name: "hostname", unique: true

spec/factories/worker_factory.rb

@@ -4,5 +4,6 @@
     sequence(:worker_id)
     queue "@default"
     working true
+    suspendable true
   end
 end

spec/features/workers_spec.rb

@@ -44,4 +44,37 @@
     expect(page).not_to have_content('echo Hello!')
     expect(page).to have_selector('#workers table tbody tr td .btn', text: 'Details', count: 0)
   end
+
+  context 'toggle suspended' do
+    it js: true do
+      visit kuroko2.workers_path
+      expect(page).to have_selector('#workers table tbody tr', count: 2)
+      expect(page).not_to have_content('echo Hello!')
+      expect(page).to have_title('Kuroko Workers « Kuroko 2')
+      expect(page).to have_selector('i.fa.fa-rocket', text: '')
+      have_selector('h1', text: /Kuroko Workers/)
+
+      expect(page).to have_selector('#workers table tbody tr', count: 2)
+      expect(page).to have_selector('#workers table tbody tr td .btn[value=Suspend]', count: 1)
+      expect(page).to have_selector('#workers table tbody tr td .btn[value=Unsuspend]', count: 0)
+      expect(page).to have_selector('#workers table tbody tr td .label', text: 'WORKING', count: 1)
+      expect(page).to have_selector('#workers table tbody tr td .label', text: 'SUSPENDED', count: 0)
+
+      click_on 'Suspend'
+
+      expect(page).to have_selector('#workers table tbody tr', count: 2)
+      expect(page).to have_selector('#workers table tbody tr td .btn[value=Suspend]', count: 0)
+      expect(page).to have_selector('#workers table tbody tr td .btn[value=Unsuspend]', count: 1)
+      expect(page).to have_selector('#workers table tbody tr td .label', text: 'WORKING', count: 0)
+      expect(page).to have_selector('#workers table tbody tr td .label', text: 'SUSPENDED', count: 1)
+
+      click_on 'Unsuspend'
+
+      expect(page).to have_selector('#workers table tbody tr', count: 2)
+      expect(page).to have_selector('#workers table tbody tr td .btn[value=Suspend]', count: 1)
+      expect(page).to have_selector('#workers table tbody tr td .btn[value=Unsuspend]', count: 0)
+      expect(page).to have_selector('#workers table tbody tr td .label', text: 'WORKING', count: 1)
+      expect(page).to have_selector('#workers table tbody tr td .label', text: 'SUSPENDED', count: 0)
+    end
+  end
 end