Capistrano 3 Rails 4 deploy example with public key auth

deploy_files.rb

# Gemfile
#
group :development do
  gem 'capistrano', '~> 3.0.0'
  gem 'capistrano-rails', '~> 0.0.7'
  gem 'capistrano-bundler', '~> 0.0.1'
end

# Capfile
#

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

# Includes default deployment tasks
require 'capistrano/deploy'

# Includes tasks from other gems included in your Gemfile
#
require 'capistrano/bundler'
require 'capistrano/rails'

# Loads custom tasks from `lib/capistrano/tasks' if you have any defined.
Dir.glob('lib/capistrano/tasks/*.cap').each { |r| import r }

namespace :deploy do

  desc 'Restart application'
  task :restart do
    on roles(:app), in: :sequence, wait: 5 do
      # Your restart mechanism here, for example:
      # execute :touch, release_path.join('tmp/restart.txt')
    end
  end

  after :restart, :clear_cache do
    on roles(:web), in: :groups, limit: 3, wait: 10 do
      # Here we can do anything such as:
      # within release_path do
      #   execute :rake, 'cache:clear'
      # end
    end
  end
  after :finishing, 'deploy:cleanup'
end

# deploy.rb
#

SSHKit.config.command_map[:rake]  = "bundle exec rake"

set :application, 'example.com'
set :repo_url, 'git@github.com:craigmcnamara/site-repo.git'

set :ssh_options, {
  user: 'deploy',
  forward_agent: true,
  auth_methods: %w(publickey)
}

set :deploy_to, '/home/deploy'