callbacks.rb

namespace :deploy do

# this can probably be done better once bundler is updated or you can lock before deploying
# but I really like the way bundler 0.8.1 just updated the gems on the fly from the cache
# I also really don't like deploying all my gems in the system directory, since you can run into
# really messy version conflicts. Keep the gems with the app that needs them, and your system gems clean

  desc "expand the gems"
  task :gems, :roles => :web, :except => { :no_release => true } do
    run "cd #{current_path}; #{shared_path}/bin/bundle unlock"
    run "cd #{current_path}; #{shared_path}/bin/bundle install vendor/"
    run "cd #{current_path}; #{shared_path}/bin/bundle lock"
  end

  desc 'Bundle and minify the JS and CSS files'
  task :precache_assets, :roles => :app do
    root_path = File.expand_path(File.dirname(__FILE__) + '/../..')
    assets_path = "#{root_path}/public/assets"
    run_locally "#{root_path}/vendor/bin/jammit"
    top.upload assets_path, "#{current_path}/public", :via => :scp, :recursive => true
  end

end

deploy.rb

load 'config/deploy/settings.rb'
load 'config/deploy/symlinks.rb'
load 'config/deploy/passenger.rb'
load 'config/deploy/callbacks.rb'
load 'config/deploy/maintenance.rb'
load 'config/deploy/git.rb'

git.rb

namespace :deploy do
  desc "Deploy app"
  task :default do
    update
    restart
    cleanup
  end

# note: the shared children is where we setup for the new bundler
# to share the deploy of the gems between deploys. this is kind of bad
# since we're re-installing all of them each deploy. Hope to fix this
# when bundler gets updated to just install new via the cache like 0.8.1

  desc "Setup a GitHub-style deployment."
  task :setup, :except => { :no_release => true } do
    run "[ -d #{current_path} ] || git clone #{repository} #{current_path}"
    set (:shared_path) { File.join(deploy_to, shared_dir) }
    set :shared_children, %w(public/system log config gems specifications doc bin)
    dirs = [shared_path]
    dirs += shared_children.map { |d| File.join(shared_path, d) }
    run "#{try_sudo} mkdir -p #{dirs.join(' ')} && #{try_sudo} chmod g+w #{dirs.join(' ')}"
  end

  desc "Update the deployed code."
  task :update_code, :except => { :no_release => true } do
    run "cd #{current_path}; git fetch origin; git reset --hard origin/#{branch}"
  end

  desc "Deploy and run migrations"
  task :migrations, :except => { :no_release => true } do
    update
    restart
    cleanup
  end

  desc "write the current version to REVISION"
  task :write_revision, :except => { :no_release => true } do
    run "cd #{current_path}; git rev-parse HEAD > #{current_path}/REVISION"
  end

  namespace :rollback do
    desc "Rollback"
    task :default do
      code
    end

    desc "Rollback a single commit."
    task :code, :except => { :no_release => true } do
      set :branch, "HEAD^"
      default
    end
  end

  # cleanup is a non-op with github deploy strat
  desc "Cleanup releases"
  task :cleanup do
  end

  desc "Make sure there is something to deploy"
  task :check_revision, :roles => [:web] do
    unless `git rev-parse HEAD` == `git rev-parse origin/#{branch}`
      puts ""
      puts "  **************************************************"
      puts "  * WARNING: HEAD is not the same as origin/#{branch} *"
      puts "  **************************************************"
      puts ""
      exit
    end
  end

end

maintenance.rb

#############################################################
#	Other Tasks
#############################################################
# don't really use this, so it may not work 100% but included
# for completeness

namespace :deploy do
  namespace :web do
    desc "Serve up a custom maintenance page."
    task :disable, :roles => :web do
      require 'erb'
      on_rollback { run "rm #{shared_path}/system/maintenance.html" }

      reason      = ENV['REASON']
      deadline    = ENV['UNTIL']

      template = File.read("app/views/layouts/maintenance.html.erb")
      page = ERB.new(template).result(binding)

      put page, "#{shared_path}/system/maintenance.html", :mode => 0644
    end
  end
end

passenger.rb

namespace :deploy do
  # override default tasks to make capistrano happy
  desc "Start Passenger"
  task :start do
    run "touch #{current_path}/tmp/restart.txt"
  end

  desc "Restart Passenger"
  task :restart do
    stop
    start
  end

  desc "Stop Passenger"
  task :stop do
  end
end

settings.rb

#############################################################
#	Application
#############################################################

set :application, 'appname'
set :deploy_to, "/home/username/website/"

#use trunk to deploy to production
  set :branch, "master"
  set :rails_env, "production"

#production
  set :domain, 'domainname'
  role :app, domain
  role :web, domain
  role :db, domain, :primary => true

#############################################################
#	Git
#############################################################

set :scm, :git
set :repository,  "repository-location"

#############################################################
#	Servers
#############################################################

set :user, 'dreamhost-username'

#############################################################
#	Includes
#############################################################

#############################################################
#	Settings
#############################################################

default_run_options[:pty] = true
set :use_sudo, false
#before "deploy", "deploy:check_revision"
set :ssh_options, {:forward_agent => true}

#############################################################
#	Post Deploy Hooks
#############################################################

after "deploy:update_code", "deploy:write_revision"
before "deploy:gems", "deploy:symlink"
after "deploy:update_code", "deploy:gems"
#after "deploy:update_code", "deploy:precache_assets" #not working for rails3 yet

symlinks.rb

# symlinks are setup for bundler deploy, and are based on 0.8.1 version
# of being able to bundle from the cache. right now it's re-deploying
# everything. I'd like to get this fixed at some point

namespace :deploy do
  desc "Make all the symlinks"
  task :symlink, :roles => :app, :except => { :no_release => true } do
    set :normal_symlinks, %w(public/system config/database.yml log)

    commands = normal_symlinks.map do |path|
      "rm -rf #{current_path}/#{path} && ln -s #{shared_path}/#{path} #{current_path}/#{path}"
    end

    set :weird_symlinks, {
      "#{shared_path}/bin" => "vendor/bin",
      "#{shared_path}/specifications" => "vendor/specifications",
      "#{shared_path}/gems" => "vendor/gems",
      "#{shared_path}/doc" => "vendor/doc"
    }

    commands += weird_symlinks.map do |from, to|
      "rm -rf #{current_path}/#{to} && ln -s #{from} #{current_path}/#{to}"
    end

    # needed for some of the symlinks
    run "mkdir -p #{current_path}/tmp && mkdir -p #{current_path}/config"
    run "cd #{current_path} && #{commands.join(' && ')}"
  end
end