Files from http://roots.io/screencasts/deploying-wordpress-with-capistrano/

Capfile

# Load DSL and Setup Up Stages
require 'capistrano/setup'

# Includes default deployment tasks
require 'capistrano/deploy'

# Custom tasks

require 'capistrano/composer'
require 'capistrano/npm'
require 'capistrano/grunt'

deploy.rb

set :application, 'roots.io'
set :repo_url, 'git@github.com:retlehs/roots.io.git'

set :branch, :master

set :deploy_to, '/srv/www/roots.io'

set :log_level, :info
set :pty, true

set :linked_dirs, %w{media}
set :linked_files, %w{.env}

set :theme_path, "#{release_path}/app/themes/roots"

set :npm_target_path, fetch(:theme_path)
set :grunt_target_path, fetch(:theme_path)

namespace :deploy do

  desc 'Restart application'
  task :restart do
    on roles(:app) do
      sudo 'service', 'nginx', 'reload'
    end
  end

end

before 'deploy:updated', 'grunt'

Gemfile

source 'https://rubygems.org'

gem 'capistrano', '~> 3.0.1'
gem 'capistrano-composer'
gem 'capistrano-npm'
gem 'capistrano-grunt'

production.rb

set :stage, :production

server 'roots.io', user: 'deploy', roles: %w{web app db}

set :ssh_options, {
  forward_agent: true
}

staging.rb

set :stage, :staging

server 'roots.dev', user: 'vagrant', roles: %w{web app db}

# Vagrant specific
set :ssh_options, {
  keys: %w(~/.vagrant.d/insecure_private_key)
}