Multistage Capistrano Recipe

Capfile

load 'deploy' if respond_to?(:namespace) # cap2 differentiator

require 'bundler/capistrano'

# Uncomment if you are using Rails' asset pipeline
load 'deploy/assets'

Dir['vendor/gems/*/recipes/*.rb','vendor/plugins/*/recipes/*.rb'].each { |plugin| load(plugin) }

load 'config/deploy' # remove this line to skip loading any of the default tasks

deploy.rb

require 'capistrano/ext/multistage'

set :stages, %w(staging production)
set :default_stage, 'staging'

set :scm, :git
set :repository, "your_repository_here"
set :ssh_options, { :forward_agent => true }
set :deploy_via, :remote_cache

set :application, "your_application_name"

namespace :deploy do
  task :default do
    set(:branch) do
      br = Capistrano::CLI.ui.ask "What branch do you want to deploy?: ".downcase
      raise 'You can only deploy master branch to production.' if (stage.to_s.upcase == 'PRODUCTION') && br != 'master'
      br
    end
    puts "*** Deploying to the #{stage.to_s.upcase} server!"
    update
    restart
    
    # Clean up old deployments
    deploy.cleanup
    
    # Send deployment notification except, for the default stage
  end
  
  # override migrations task to inject branch
  desc <<-DESC
  Deploy and run pending migrations. This will work similarly to the \
  'deploy' task, but will also run any pending migrations (via the \
  'deploy:migrate' task) prior to updating the symlink. Note that the \
  update in this case it is not atomic, and transactions are not used, \
  because migrations are not guaranteed to be reversible.
  DESC
  task :migrations do
    set :migrate_target, :latest
    set(:branch) do
      br = Capistrano::CLI.ui.ask 'What branch do you want to deploy?: '.downcase
      raise 'You can only deploy master branch to production.' if (stage.to_s.upcase == 'PRODUCTION') && br != 'master'
      br
    end
    puts "*** Deploying to the #{stage.to_s.upcase} server!"
    update_code
    migrate
    symlink
    restart

    # cleanup old deployments
    deploy.cleanup

    # Send deployment notification, except for the default stage
  end
  
  desc "Create symlink to shared files and folders on each release."
  task :symlink_shared do
    # run "mkdir -p #{shared_dir}/bundle && ln -nfs #{shared_path}/bundle #{release_path}/.bundle"
    run "ln -nfs #{shared_path}/config/database.yml #{release_path}/config/database.yml"
    run "ln -nfs #{shared_path}/assets #{release_path}/public/assets"
  end
  
  after "deploy:update_code", "deploy:symlink_shared"
end

staging.rb

$:.unshift(File.expand_path('./lib', ENV['rvm_path']))
require 'rvm/capistrano'

default_run_options[:pty] = true

set :domain,          "staging.your_domain.com"
set :deploy_to,       "/your_deploy_path/#{application}"
set :use_sudo,        false
set :rvm_ruby_string, "ruby-1.9.2-p290@your_application_name"
set :rails_env,       "staging"

role :app, "#{domain}"
role :web, "#{domain}"
role :db,  "#{domain}", :primary => true

set :user,     "user_name"
# set :password, "deploy2k" # not necessary if using ssh keys

namespace :deploy do
  task :start do ; end
  task :stop do ; end
  task :restart, :roles => :app, :except => { :no_release => true } do
    run "#{try_sudo} touch #{File.join(current_path,'tmp','restart.txt')}"
  end
end