capistrano 3 をできるだけシンプルにサーバーにコマンドを流し込むツールとして使いこなす ref: http://qiita.com/kazuph/items/deeaa7d3f9889674d7fe

deploy.rb

lock '3.2.1'
set :pty, true

dev.rb

namespace :utils do
  task :ls do
    on roles(:app) do
      execute "ls"
    end
  end
  task :perl_version do
    on roles(:app) do
      execute %[perl -v]
    end
  end
end

file0.txt

$ bundle init
$ echo gem "capistrano" >> Gemfile
$ bundle install
$ cap install

file1.txt

$ cap -V
Capistrano Version: 3.2.1 (Rake Version: 10.3.2)

file10.txt

$ bundle exec cap dev utils:perl_version

INFO[444094bb] Running /usr/bin/env perl -v on +HFOWFLWKEJF+WLEHF
DEBUG[444094bb] Command: perl -v
DEBUG[444094bb]
DEBUG[444094bb]         This is perl, v5.10.1 (*) built for x86_64-linux-thread-multi
DEBUG[444094bb]
DEBUG[444094bb]         Copyright 1987-2009, Larry Wall
DEBUG[444094bb]
DEBUG[444094bb]         Perl may be copied only under the terms of either the Artistic License or the
DEBUG[444094bb]         GNU General Public License, which may be found in the Perl 5 source kit.
DEBUG[444094bb]
DEBUG[444094bb]         Complete documentation for Perl, including FAQ lists, should be found on
DEBUG[444094bb]         this system using "man perl" or "perldoc perl".  If you have access to the
DEBUG[444094bb]         Internet, point your browser at http://www.perl.org/, the Perl Home Page.
DEBUG[444094bb]
INFO[444094bb] Finished in 1.874 seconds with exit status 0 (successful).

file12.txt

$ bundle exec cap dev utils:perl_version

INFO[444094bb] Running /usr/bin/env perl -v on LHFWLKEFJWEFJ
DEBUG[444094bb] Command: perl -v
DEBUG[444094bb]
DEBUG[444094bb]         This is perl, v5.10.1 (*) built for x86_64-linux-thread-multi
DEBUG[444094bb]
DEBUG[444094bb]         Copyright 1987-2009, Larry Wall
DEBUG[444094bb]
DEBUG[444094bb]         Perl may be copied only under the terms of either the Artistic License or the
DEBUG[444094bb]         GNU General Public License, which may be found in the Perl 5 source kit.
DEBUG[444094bb]
DEBUG[444094bb]         Complete documentation for Perl, including FAQ lists, should be found on
DEBUG[444094bb]         this system using "man perl" or "perldoc perl".  If you have access to the
DEBUG[444094bb]         Internet, point your browser at http://www.perl.org/, the Perl Home Page.
DEBUG[444094bb]
INFO[444094bb] Finished in 1.874 seconds with exit status 0 (successful).

file13.txt

bundle exec cap dev utils:echo user_name=kazuph

file16.txt

$ bundle exec cap dev utils:echo
Please enter user_name (): kazuph
INFO[62046886] Running /usr/bin/env echo kazuph on example.com
DEBUG[62046886] Command: echo kazuph
INFO[62046886] Finished in 2.086 seconds with exit status 0 (successful).
DEBUG[62046886]         kazuph
INFO[62046886] Finished in 2.086 seconds with exit status 0 (successful).

file19.txt

INFO[29ab7cc8] Running /usr/bin/env sudo whoami on +LHKFlkL+FHLEWJF
DEBUG[29ab7cc8] Command: sudo whoami
DEBUG[29ab7cc8]         sudo
DEBUG[29ab7cc8]         :
DEBUG[29ab7cc8]         sudo を実行するには tty がなければいけません。すみません
DEBUG[29ab7cc8]
cap aborted!

file2.txt

$ tree
.
├── Capfile
├── Gemfile
├── Gemfile.lock
├── config
│   ├── deploy
│   │   ├── production.rb
│   │   └── staging.rb
│   └── deploy.rb
└── lib
    └── capistrano
            └── tasks

file22.txt

# 最初のexecute
/usr/bin/env whoami

# ２つ目のexecute
/usr/bin/env if ! sudo -u fuga whoami > /dev/null; then echo "You cannot switch to user 'fuga' using sudo, please check the sudoers file" 1>&2; false; fi on example.com

file4.txt

└─- config
   └── deploy
       ├── production.rb
       ├── staging.rb
       └── dev.rb

file6.txt

$ cap dev YOUR_TASK_NAME

file8.txt

$ bundle exec cap dev ls

INFO[6a60919c] Running /usr/bin/env ls on example.com
DEBUG[6a60919c] Command: /usr/bin/env ls
DEBUG[6a60919c]         <<ここにファイル一覧が表示される>>
INFO[6a60919c] Finished in 1.851 seconds with exit status 0 (successful).

utils.rake

  task :upload_dir_all do
    on roles(:app) do
      execute :mkdir, '-p', '/home/hoge/cap_sample'
      upload! '.', '/home/hoge/cap_sample', recursive: true
      execute :tree, '-L 2 /home/hoge/cap_sample'
    end
  end