better restarts

lib/capistrano-thin.rb

@@ -1,7 +1,21 @@
+require 'erb'
+
 Capistrano::Configuration.instance.load do
-  set(:thin_command) { 'bundle exec thin' }
-  set(:thin_config_file) { 'thin.yml' }
-  set(:thin_config) { "-C #{thin_config_file}" }
+  def self.cset(variable, *args, &block)
+    set(variable, *args, &block) if !exists?(variable)
+  end
+
+  cset(:thin_command) { 'bundle exec thin' }
+  cset(:thin_config_file) { "#{current_path}/thin.yml" }
+  cset(:thin_config) { "-C #{thin_config_file}" }
+
+  cset(:thin_port) { 3000 }
+  cset(:thin_pid) { 'tmp/pids/thin.pid' }
+  cset(:thin_log) { 'log/thin.log' }
+  cset(:thin_max_conns) { 1024 }
+  cset(:thin_max_persistent_conns) { 512 }
+
+  cset(:thin_servers) { 4 }
 
   namespace :deploy do
     task :start do
@@ -13,9 +27,45 @@ Capistrano::Configuration.instance.load do
     end
 
     task :restart do
-      top.deploy.stop
-      top.deploy.start
-    end
+      run "cd #{current_path} && #{thin_command} #{thin_config} -O restart"
     end
   end
 
+  def skel_for(file)
+    File.join(File.expand_path('../../skel', __FILE__), file)
+  end
+
+  def render_skel(file, target)
+    run "mkdir -p #{File.dirname(target)}"
+    top.upload StringIO.new(ERB.new(File.read(skel_for(file))).result(binding)), target
+  end
+
+  def retrieve_env
+    fetch(:rails_env, fetch(:rack_env, fetch(:stage, :production)))
+  end
+
+  namespace :thin do
+    task :god do
+      render_skel "god/thin.god.erb",  "#{shared_path}/god/#{application}-thin.god"
+    end
+
+    task :config do
+      render_skel "thin/thin.yml.erb", thin_config_file
+    end
+
+    task :shared_pids do
+      run "mkdir -p #{shared_path}/pids"
+    end
+
+    task :rolling_restart do
+      run "rm -Rf #{current_path}/tmp/pids && mkdir -p #{current_path}/tmp && ln -sf #{shared_path}/pids #{current_path}/tmp/pids"
+
+      top.deploy.restart
+    end
+  end
+
+  after 'deploy:setup', 'thin:god', 'thin:config', 'thin:shared_pids'
+
+  after 'deploy:symlink', 'thin:rolling_restart'
+end
+

skel/god/thin.god.erb

@@ -0,0 +1,14 @@
+God.watch do |w|
+  w.name = "<%= application %>-thin"
+  w.interval = 30.seconds
+
+  pid = "<%= thin_pid %>"
+
+  template = 'bash -c "cd <%= current_dir %> && RAILS_ENV=<%= retrieve_env %> <%= thin_command %> <%= thin_config %> %s"'
+
+  w.start = template % [ 'start' ]
+  w.stop = template % [ 'stop' ]
+
+  w.pid_file = pid
+end
+

skel/thin/thin.yml.erb

@@ -0,0 +1,15 @@
+pid: <%= thin_pid %>
+address: 127.0.0.1
+timeout: 30
+wait: 30
+port: <%= thin_port %>
+log: <%= thin_log %>
+max_conns: <%= thin_max_conns %>
+require: []
+
+environment: <%= retrieve_env %>
+max_persistent_conns: <%= thin_max_persistent_conns %>
+servers: <%= thin_servers %>
+daemonize: true
+chdir: <%= current_path %>
+