Bootstrap Action Cable and Unicorn

Gemfile

@@ -3,6 +3,9 @@ source 'https://rubygems.org'
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '5.0.0.1'
 
+gem 'actioncable', '5.0.0.1'
+gem 'redis'
+
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
@@ -116,6 +119,8 @@ group :development do
   # Access an IRB console on exception pages or by using <%= console %> in views
 
   gem 'web-console'
+
+  gem 'rack-handlers'
 end
 
 group :development, :test do

Gemfile.lock

@@ -417,6 +417,8 @@ GEM
       pry (~> 0.10)
     public_suffix (2.0.4)
     rack (2.0.1)
+    rack-handlers (0.7.3)
+      rack
     rack-oauth2 (1.4.0)
       activesupport (>= 2.3)
       attr_required (>= 0.0.5)
@@ -465,6 +467,7 @@ GEM
       nokogiri (~> 1.5)
       trollop (~> 2.1)
     rdoc (4.3.0)
+    redis (3.3.0)
     ref (2.0.0)
     request_store (1.3.1)
     responders (2.3.0)
@@ -624,6 +627,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  actioncable (= 5.0.0.1)
   active_model_serializers
   apipie-rails
   as_csv
@@ -665,9 +669,11 @@ DEPENDENCIES
   pg
   poltergeist
   pry-byebug
+  rack-handlers
   railroady
   rails (= 5.0.0.1)
   rails-controller-testing
+  redis
   rest-client
   rgeo-geojson
   rspec-rails (~> 3.0)

app/assets/javascripts/cable.js

@@ -0,0 +1,13 @@
+// Action Cable provides the framework to deal with WebSockets in Rails.
+// You can generate new channels where WebSocket features live using the rails generate channel command.
+//
+//= require action_cable
+//= require_self
+//= require_tree ./channels
+
+(function() {
+    this.App || (this.App = {});
+
+    App.cable = ActionCable.createConsumer();
+
+}).call(this);

app/channels/application_cable/channel.rb

@@ -0,0 +1,5 @@
+# Be sure to restart your server when you modify this file. Action Cable runs in a loop that does not support auto reloading.
+module ApplicationCable
+  class Channel < ActionCable::Channel::Base
+  end
+end

app/channels/application_cable/connection.rb

@@ -0,0 +1,5 @@
+# Be sure to restart your server when you modify this file. Action Cable runs in a loop that does not support auto reloading.
+module ApplicationCable
+  class Connection < ActionCable::Connection::Base
+  end
+end

app/jobs/application_job.rb

@@ -0,0 +1,2 @@
+class ApplicationJob < ActiveJob::Base
+end

app/models/application_record.rb

@@ -0,0 +1,3 @@
+class ApplicationRecord < ActiveRecord::Base
+  self.abstract_class = true
+end

app/views/layouts/application.html.haml

@@ -9,6 +9,7 @@
     = javascript_include_tag 'application', 'data-turbolinks-track' => true
 
     = csrf_meta_tags
+    = action_cable_meta_tag
   %body
     = render partial: 'layouts/support_navigator_banner'
     #beta{class:(Rails.env == 'production' ? '' : 'beta_staging')}

config.ru

@@ -1,4 +1,8 @@
 # This file is used by Rack-based servers to start the application.
 
 require ::File.expand_path('../config/environment', __FILE__)
+
+# Action Cable requires that all classes are loaded in advance
+Rails.application.eager_load!
+
 run Rails.application

config/cable.yml

@@ -0,0 +1,10 @@
+production:
+  adapter: redis
+  url: redis://localhost:6379
+
+development:
+  adapter: redis
+  url: redis://localhost:6379
+
+test:
+  adapter: async

config/environments/development.rb

@@ -45,5 +45,5 @@ Rails.application.configure do
   # Raises error for missing translations
   # config.action_view.raise_on_missing_translations = true
 
-
+  config.action_cable.url = "ws://localhost:3000/cable"
 end

config/routes.rb

@@ -202,4 +202,6 @@ Rails.application.routes.draw do
   end
 
   apipie
+
+  mount ActionCable.server => '/cable'
 end

config/unicorn.rb

@@ -0,0 +1,109 @@
+# Sample verbose configuration file for Unicorn (not Rack)
+#
+# This configuration file documents many features of Unicorn
+# that may not be needed for some applications. See
+# http://unicorn.bogomips.org/examples/unicorn.conf.minimal.rb
+# for a much simpler configuration file.
+#
+# See http://unicorn.bogomips.org/Unicorn/Configurator.html for complete
+# documentation.
+
+
+
+# Use at least one worker per core if you're on a dedicated server,
+# more will usually help for _short_ waits on databases/caches.
+worker_processes 2
+
+# Since Unicorn is never exposed to outside clients, it does not need to
+# run on the standard HTTP port (80), there is no reason to start Unicorn
+# as root unless it's from system init scripts.
+# If running the master process as root and the workers as an unprivileged
+# user, do this to switch euid/egid in the workers (also chowns logs):
+# user "unprivileged_user", "unprivileged_group"
+
+# Help ensure your application will always spawn in the symlinked
+# "current" directory that Capistrano sets up.
+
+# listen on both a Unix domain socket and a TCP port,
+# we use a shorter backlog for quicker failover when busy
+listen "127.0.0.1:3000", :tcp_nopush => true
+
+# nuke workers after 30 seconds instead of 60 seconds (the default)
+timeout 30
+
+# By default, the Unicorn logger will write to stderr.
+# Additionally, ome applications/frameworks log to stderr or stdout,
+# so prevent them from going to /dev/null when daemonized here:
+
+# combine Ruby 2.0.0dev or REE with "preload_app true" for memory savings
+# http://rubyenterpriseedition.com/faq.html#adapt_apps_for_cow
+preload_app true
+GC.respond_to?(:copy_on_write_friendly=) and
+  GC.copy_on_write_friendly = true
+
+# Enable this flag to have unicorn test client connections by writing the
+# beginning of the HTTP headers before calling the application.  This
+# prevents calling the application for connections that have disconnected
+# while queued.  This is only guaranteed to detect clients on the same
+# host unicorn runs on, and unlikely to detect disconnects even on a
+# fast LAN.
+check_client_connection false
+
+# local variable to guard against running a hook multiple times
+run_once = true
+
+
+before_fork do |server, worker|
+  # the following is highly recomended for Rails + "preload_app true"
+  # as there's no need for the master process to hold a connection
+  defined?(ActiveRecord::Base) and
+    ActiveRecord::Base.connection.disconnect!
+
+  # Occasionally, it may be necessary to run non-idempotent code in the
+  # master before forking.  Keep in mind the above disconnect! example
+  # is idempotent and does not need a guard.
+  if run_once
+    # do_something_once_here ...
+    run_once = false # prevent from firing again
+  end
+
+  # The following is only recommended for memory/DB-constrained
+  # installations.  It is not needed if your system can house
+  # twice as many worker_processes as you have configured.
+  #
+  # # This allows a new master process to incrementally
+  # # phase out the old master process with SIGTTOU to avoid a
+  # # thundering herd (especially in the "preload_app false" case)
+  # # when doing a transparent upgrade.  The last worker spawned
+  # # will then kill off the old master process with a SIGQUIT.
+  old_pid = "#{server.config[:pid]}.oldbin"
+  if old_pid != server.pid
+    begin
+      sig = (worker.nr + 1) >= server.worker_processes ? :QUIT : :TTOU
+      Process.kill(sig, File.read(old_pid).to_i)
+    rescue Errno::ENOENT, Errno::ESRCH
+    end
+  end
+  #
+  # Throttle the master from forking too quickly by sleeping.  Due
+  # to the implementation of standard Unix signal handlers, this
+  # helps (but does not completely) prevent identical, repeated signals
+  # from being lost when the receiving process is busy.
+  sleep 1
+end
+
+after_fork do |server, worker|
+  # per-process listener ports for debugging/admin/migrations
+  # addr = "127.0.0.1:#{9293 + worker.nr}"
+  # server.listen(addr, :tries => -1, :delay => 5, :tcp_nopush => true)
+
+  # the following is *required* for Rails + "preload_app true",
+  defined?(ActiveRecord::Base) and
+    ActiveRecord::Base.establish_connection
+
+  # if preload_app is true, then you may also want to check and
+  # restart any other shared sockets/descriptors such as Memcached,
+  # and Redis.  TokyoCabinet file handles are safe to reuse
+  # between any number of forked children (assuming your kernel
+  # correctly implements pread()/pwrite() system calls)
+end