Replace puma with unicorn

Gemfile

@@ -32,8 +32,8 @@ group :development, :test do
 end
 
 group :production do
-  gem 'puma'
   gem 'skylight'
+  gem 'unicorn'
 end
 
 group :test do

Gemfile.lock

@@ -93,6 +93,7 @@ GEM
     kaminari (0.16.3)
       actionpack (>= 3.0.0)
       activesupport (>= 3.0.0)
+    kgio (2.9.3)
     loofah (2.0.3)
       nokogiri (>= 1.5.9)
     mail (2.6.3)
@@ -114,7 +115,6 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
-    puma (2.13.4)
     rack (1.6.4)
     rack-pjax (0.8.0)
       nokogiri (~> 1.5)
@@ -165,6 +165,7 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
     rainbow (2.0.0)
+    raindrops (0.15.0)
     rake (10.4.2)
     remotipart (1.2.1)
     responders (2.1.0)
@@ -218,6 +219,10 @@ GEM
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.7.1)
+    unicorn (4.9.0)
+      kgio (~> 2.6)
+      rack
+      raindrops (~> 0.7)
     validates_formatting_of (0.9.0)
       activemodel
     warden (1.2.3)
@@ -240,7 +245,6 @@ DEPENDENCIES
   nokogiri
   pg
   pry
-  puma
   rails (~> 4.2.4)
   rails_12factor
   rails_admin
@@ -251,6 +255,7 @@ DEPENDENCIES
   spring
   sqlite3
   uglifier
+  unicorn
   validates_formatting_of
   webmock
 

Procfile

@@ -1 +1 @@
-web: bundle exec puma -p $PORT
+web: bundle exec unicorn -p $PORT -c ./config/unicorn.rb

config/unicorn.rb

@@ -0,0 +1,18 @@
+worker_processes 3
+timeout 30
+preload_app true
+
+before_fork do |server, worker|
+  Signal.trap 'TERM' do
+    puts 'Unicorn master intercepting TERM and sending myself QUIT instead'
+    Process.kill 'QUIT', Process.pid
+  end
+  ActiveRecord::Base.connection.disconnect!
+end
+
+after_fork do |server, worker|
+  Signal.trap 'TERM' do
+    puts 'Unicorn worker intercepting TERM and doing nothing. Wait for master to sent QUIT'
+  end
+  ActiveRecord::Base.establish_connection
+end