capistrano3のデプロイを把握する ref: http://qiita.com/taizo/items/afff46a260bd11588962

file0.txt

$ gem install capistrano
$ cap install
mkdir -p config/deploy
create config/deploy.rb
create config/deploy/staging.rb
create config/deploy/production.rb
mkdir -p lib/capistrano/tasks
Capified
$ cap staging deploy --dry-run
** Invoke staging (first_time)
** Execute (dry run) staging
** Invoke deploy (first_time)
** Execute (dry run) deploy

file1.txt

deploy:starting
  deploy:check
    #{scm}:check
    deploy:check:directories
    deploy:check:linked_dirs
    deploy:check:make_linked_dirs
    deploy:check:linked_files
  deploy:set_previous_revision
deploy:started
deploy:updating
  #{scm}:create_release
  deploy:symlink:shared
    deploy:symlink:linked_files
    deploy:symlink:linked_dirs
deploy:updated
deploy:publishing
  deploy:symlink:release
deploy:published
deploy:finishing
  deploy:cleanup
deploy:finished
  deploy:log_revision

file2.yml

deploy:starting
  deploy:check
    #{scm}:check
    deploy:check:directories
    deploy:check:linked_dirs
    deploy:check:make_linked_dirs
    deploy:check:linked_files
  deploy:set_previous_revision
deploy:started
deploy:updating
  #{scm}:create_release
  deploy:symlink:shared
    deploy:symlink:linked_files
    deploy:symlink:linked_dirs
deploy:updated
  deploy:compile_assets            # 追加
    deploy:assets:precompile       # 追加
    deploy:assets:backup_manifest  # 追加
  deploy:normalize_assets          # 追加
deploy:publishing
  deploy:symlink:release
deploy:published
deploy:finishing
  deploy:cleanup
deploy:finished
  deploy:log_revision

file3.yml

deploy:starting
  deploy:check
    #{scm}:check
    deploy:check:directories
    deploy:check:linked_dirs
    deploy:check:make_linked_dirs
    deploy:check:linked_files
  deploy:set_previous_revision
deploy:started
deploy:updating
  #{scm}:create_release
  deploy:symlink:shared
    deploy:symlink:linked_files
    deploy:symlink:linked_dirs
deploy:updated
  deploy:migrate                # 追加
deploy:publishing
  deploy:symlink:release
deploy:published
deploy:finishing
  deploy:cleanup
deploy:finished
  deploy:log_revision

file4.yml

deploy:starting
  deploy:check
    #{scm}:check
    deploy:check:directories
    deploy:check:linked_dirs
    deploy:check:make_linked_dirs
    deploy:check:linked_files
  deploy:set_previous_revision
deploy:started
deploy:updating
  #{scm}:create_release
  deploy:symlink:shared
    deploy:symlink:linked_files
    deploy:symlink:linked_dirs
npm:install                      # 追加
deploy:updated 
deploy:publishing
  deploy:symlink:release
deploy:published
deploy:finishing
  deploy:cleanup
deploy:finished
  deploy:log_revision

npm.rake

namespace :npm do
  desc <<-DESC
    # 省略
  DESC
  task :install do  # npm:install タスクを作成
    on roles fetch(:npm_roles) do
      within fetch(:npm_target_path, release_path) do
        execute :npm, 'install', fetch(:npm_flags)
      end
    end
  end

  before 'deploy:updated', 'npm:install' # deploy:updateの前に npm:install を実行する
  # ...
end