Capsitrano deploy script for deploying to an 'ivanvanderbyl:application deployed' server.

database.yml

production:
  adapter: postgresql
  encoding: unicode
  database: my_application
  pool: 5
  host: 127.0.0.1

deploy.rb

load 'deploy/assets'

set :bundle_roles, [:app]    #{:except => {:no_release => true}} # e.g. [:app, :batch]
require 'bundler/capistrano'

set :application, "my_application_name"
set :repository,  "git@github:username/my_application_name.git"
set :user, 'deploy'
set :use_sudo, false

set :scm, :git
set :branch, "master"
set :deploy_via, :remote_cache
set :git_shallow_clone, 1

# Deploy application to /home/deploy/my_application_name/current
set :deploy_to, "~/#{application}"
set :keep_releases, 3

role :web, "hostname_or_ip.com"
role :app, "hostname_or_ip.com"
role :db,  "hostname_or_ip.com", :primary => true

set :application_env, 'production'

set :bundle_gemfile,  "Gemfile"
set :bundle_dir,      File.join(fetch(:shared_path), 'bundle')
set :bundle_flags,    "--deployment --quiet"
set :bundle_without,  [:development, :test]
set :bundle_cmd,      "bundle" # e.g. "/opt/ruby/bin/bundle"

set :normalize_asset_timestamps, false

require 'capistrano-unicorn'

before  'deploy:finalize_update', 'deploy:symlink_sockets'
after   'deploy', 'deploy:cleanup'
before  'deploy', 'set_start_time'
after   'deploy', 'log_duration'

# This will symlink tmp/{sockets,pids}
# You may also want to symlink a production database.yml, unelss you are
# using postgres access, in which case you can remove the username and password
# keys from committed database.yml
namespace :deploy do
  task :symlink_sockets, :roles => :web, :except => { :no_release => true } do
    run <<-CMD
      rm -rf #{latest_release}/tmp/sockets &&
      ln -s #{shared_path}/sockets #{latest_release}/tmp/sockets &&
      rm -rf #{latest_release}/tmp/pids &&
      ln -s #{shared_path}/pids #{latest_release}/tmp/pids
    CMD
  end
end

task :set_start_time do
  set :started_at, Time.now.to_f
end

# Output the deploy duration to console
task :log_duration do
  logger.info "Deploy completed in %1.4f seconds" % (Time.now.to_f - started_at)
end

unicorn.rb

worker_processes 4# amount of unicorn workers to spin up
timeout 15         # restarts workers that hang for 15 seconds

# combine Ruby 2.0.0dev or REE with "preload_app true" for memory savings
# http://rubyenterpriseedition.com/faq.html#adapt_apps_for_cow
preload_app true
GC.respond_to?(:copy_on_write_friendly=) and
  GC.copy_on_write_friendly = true

root = File.expand_path('../../..', __FILE__)

pid "#{root}/tmp/pids/unicorn.pid"

listen "#{root}/tmp/sockets/unicorn.socket", :backlog => 64

stderr_path "#{root}/log/unicorn.stderr.log"
stdout_path "#{root}/log/unicorn.stdout.log"

before_fork do |server, worker|
  ActiveRecord::Base.connection.disconnect! if defined?(ActiveRecord::Base)

  `cat #{server.pid}.oldbin`.scan(/^\d+$/).each {|ppid|
    `kill -QUIT #{ppid}`
  }
end

after_fork do |server, worker|
  ActiveRecord::Base.establish_connection if defined?(ActiveRecord::Base)
end

One you have this running, you may then want to add Unicorn to upstart so it comes online when you boot, and have upstart keep it alive.

I've written a babushka dep for this also:

babushka 'ivanvanderbyl:unicorn upstart'

It will ask you for a name, which is the name of the process you want to add to upstart. It will be prefixed with unicorn- e.g. Giving it testpilot will create an upstart process called unicorn-testpilot which can be controlled as follows:

sudo start unicorn-testpilot
sudo status unicorn-testpilot
sudo restart unicorn-testpilot
sudo stop unicorn-testpilot

Upstart will also respawn this process if it dies.

NOTE: You must save the unicorn configuration into config/unicorn/production.rb for this to work.