Simple Capistrano 2.15 deploy.rb file, using rbenv, apache (nginx should work too) and passenger on linode (Ubuntu 12.04 LTS)

deploy.rb

require 'bundler/capistrano'

# Config Variables

GITHUB_REPOSITORY_NAME = 'project_name'
LINODE_SERVER_HOSTNAME = 'www.host.com'

#############################################
#############################################

# General Options

set :bundle_flags,               "--deployment"

set :application,                GITHUB_REPOSITORY_NAME
set :deploy_to,                  "/the/application/path/#{application}"
set :normalize_asset_timestamps, false
set :rails_env,                  "production"

set :user,                       "deploy"
set :runner,                     "deploy"
set :admin_runner,               "deploy"

set :default_environment, {
  'PATH' => "$HOME/.rbenv/shims:$HOME/.rbenv/bin:$PATH"
}

ssh_options[:keys]          = ["~/.ssh/id_rsa"]
ssh_options[:forward_agent] = true

# SCM Options
set :scm,        :git
set :repository, "git@github.com:username/#{GITHUB_REPOSITORY_NAME}.git"
set :branch,     "master"

# Roles
role :app,     LINODE_SERVER_HOSTNAME
role :db,      LINODE_SERVER_HOSTNAME, :primary => true

# Add Configuration Files & Compile Assets
after 'deploy:update_code' do
  # Setup Configuration
  run "cp #{shared_path}/config/database.yml #{release_path}/config/database.yml"

  # Compile Assets
  run "cd #{release_path}; RAILS_ENV=production bundle exec rake assets:precompile"
end

# Restart Passenger
deploy.task :restart, :roles => :app do

  # Restart Application
  run "touch #{current_path}/tmp/restart.txt"
end