Add unicorn

Author: pavel-sazonov

Capfile

@@ -8,6 +8,7 @@ require "capistrano/bundler"
 require "capistrano/rails"
 require "capistrano/sidekiq"
 require "whenever/capistrano"
+require "capistrano3/unicorn"
 
 # Load the SCM plugin appropriate to your project:
 #

Gemfile

@@ -56,6 +56,7 @@ gem 'skim'
 gem 'slim-rails'
 gem 'therubyracer'
 gem 'thinking-sphinx'
+gem 'unicorn'
 gem 'whenever'
 
 group :production do
@@ -64,6 +65,7 @@ group :production do
   gem 'capistrano-rails', require: false
   gem 'capistrano-rvm', require: false
   gem 'capistrano-sidekiq', require: false
+  gem 'capistrano3-unicorn', require: false
 end
 
 group :development, :test do

Gemfile.lock

@@ -78,6 +78,8 @@ GEM
     capistrano-sidekiq (1.0.2)
       capistrano (>= 3.9.0)
       sidekiq (>= 3.4)
+    capistrano3-unicorn (0.2.1)
+      capistrano (~> 3.1, >= 3.1.0)
     capybara (3.0.2)
       addressable
       mini_mime (>= 0.1.3)
@@ -152,6 +154,7 @@ GEM
       rspec (>= 2.0, < 4.0)
     jsonapi-renderer (0.2.0)
     jwt (1.5.6)
+    kgio (2.11.2)
     launchy (2.4.3)
       addressable (~> 2.3)
     libv8 (3.16.14.19)
@@ -247,6 +250,7 @@ GEM
       method_source
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
+    raindrops (0.19.0)
     rake (12.3.1)
     rb-fsevent (0.10.3)
     rb-inotify (0.9.10)
@@ -351,6 +355,9 @@ GEM
       thread_safe (~> 0.1)
     uglifier (4.1.9)
       execjs (>= 0.3.0, < 3)
+    unicorn (5.4.1)
+      kgio (~> 2.6)
+      raindrops (~> 0.7)
     warden (1.2.7)
       rack (>= 1.0)
     web-console (3.6.1)
@@ -379,6 +386,7 @@ DEPENDENCIES
   capistrano-rails
   capistrano-rvm
   capistrano-sidekiq
+  capistrano3-unicorn
   capybara (>= 2.15, < 4.0)
   carrierwave
   chromedriver-helper
@@ -420,6 +428,7 @@ DEPENDENCIES
   turbolinks (~> 5)
   tzinfo-data
   uglifier (>= 1.3.0)
+  unicorn
   web-console (>= 3.3.0)
   whenever
 

config/deploy.rb

@@ -31,7 +31,8 @@
   desc "Restart application"
   task :restart do
     on roles(:app), in: :sequence, wait: 5 do
-      execute :touch, release_path.join("tmp/restart.txt")
+      # execute :touch, release_path.join("tmp/restart.txt")
+      invoke 'unicorn:restart'
     end
   end
 

config/unicorn/production.rb

@@ -0,0 +1,47 @@
+# paths
+app_path = "/home/deployer/qna"
+working_directory "#{app_path}/current"
+pid               "#{app_path}/current/tmp/pids/unicorn.pid"
+
+# listen
+listen "/tmp/unicorn.qna.sock", backlog: 64
+
+# logging
+stderr_path "log/unicorn.stderr.log"
+stdout_path "log/unicorn.stdout.log"
+
+# workers
+worker_processes 2
+
+# use correct Gemfile on restarts
+before_exec do |server|
+  ENV['BUNDLE_GEMFILE'] = "#{app_path}/current/Gemfile"
+end
+
+# preload
+preload_app 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
+  if defined?(ActiveRecord::Base)
+    ActiveRecord::Base.connection.disconnect!
+  end
+
+  # Before forking, kill the master process that belongs to the .oldbin PID.
+  # This enables 0 downtime deploys.
+  old_pid = "#{server.config[:pid]}.oldbin"
+  if File.exists?(old_pid) && server.pid != old_pid
+    begin
+      Process.kill("QUIT", File.read(old_pid).to_i)
+    rescue Errno::ENOENT, Errno::ESRCH
+      # someone else did our job for us
+    end
+  end
+end
+
+after_fork do |server, worker|
+  if defined?(ActiveRecord::Base)
+    ActiveRecord::Base.establish_connection
+  end
+end