Added missing items in Puma config file.

config/puma.rb

@@ -1,4 +1,23 @@
-workers = 2
+workers 2
+
 threads 2, 4
 
-preload_app!
+app_dir = File.expand_path("../..", __FILE__)
+shared_dir = "#{app_dir}/shared"
+
+rails_env = ENV['RAILS_ENV'] || "production"
+environment rails_env
+
+bind "unix://#{shared_dir}/sockets/puma.sock"
+
+stdout_redirect "#{shared_dir}/log/puma.stdout.log", "#{shared_dir}/log/puma.stderr.log", true
+
+pidfile "#{shared_dir}/pids/puma.pid"
+state_path "#{shared_dir}/pids/puma.state"
+activate_control_app
+
+on_worker_boot do
+  require "active_record"
+  ActiveRecord::Base.connection.disconnect! rescue ActiveRecord::ConnectionNotEstablished
+  ActiveRecord::Base.establish_connection(YAML.load_file("#{app_dir}/config/database.yml")[rails_env])
+end