update environments/production.rb add unicorn.rb, nemo.sh

config/unicorn.rb

@@ -0,0 +1,39 @@
+root=File.expand_path(File.dirname(__FILE__) + '/..')
+#shared_dir="#{root}/shared"
+working_directory root
+pid "#{root}/pids/unicorn.nemo.pid"
+stderr_path  "#{root}/log/unicorn.stderr.log"
+stdout_path  "#{root}/log/unicorn.stdout.log"
+listen "#{root}/sockets/unicorn.nemo.sock", :backlog => 64
+listen(8081, backlog: 64) if ENV['RAILS_ENV'] == 'production'
+worker_processes 2
+preload_app true
+timeout 30
+
+
+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!
+
+  ##
+  # When sent a USR2, Unicorn will suffix its pidfile with .oldbin and
+  # immediately start loading up a new version of itself (loaded with a new
+  # version of our app). When this new Unicorn is completely loaded
+  # it will begin spawning workers. The first worker spawned will check to
+  # see if an .oldbin pidfile exists. If so, this means we've just booted up
+  # a new Unicorn and need to tell the old one that it can now die. To do so
+  # we send it a QUIT.
+  #
+  # Using this method we get 0 downtime deploys.
+
+  old_pid = "#{root}/pids/unicorn.nemo.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
+