add unicorn support

config/unicorn.rb

@@ -0,0 +1,46 @@
+# Set your full path to application.
+app_path = "/var/www/danbooru2/current"
+
+# Set unicorn options
+if Socket.gethostname =~ /sonohara|hijiribe/
+  worker_processes 12
+else
+  worker_processes 1
+end
+
+preload_app false
+timeout 180
+listen "127.0.0.1:9000"
+
+# Spawn unicorn master worker for user apps (group: apps)
+user 'albert', 'albert'
+
+# Fill path to your app
+working_directory app_path
+
+# Should be 'production' by default, otherwise use other env 
+rails_env = ENV['RAILS_ENV'] || 'production'
+
+# Log everything to one file
+stderr_path "log/unicorn.log"
+stdout_path "log/unicorn.log"
+
+# Set master PID location
+pid "#{app_path}/tmp/pids/unicorn.pid"
+
+before_fork do |server, worker|
+  ActiveRecord::Base.connection.disconnect!
+
+  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|
+  ActiveRecord::Base.establish_connection
+end