Sử dụng Capistrano 3 để deploy

Có nhiều phương pháp deploy ứng dụng lên server. Bạn có thể deploy bằng tay, hay sử dụng các tool tự động hoá như Capistrano, Chef, Ansible, Fabric, ...

Bài viết này hướng dẫn các bạn deploy một ứng dụng lên server sử dụng capistrano 3

"A remote server automation and deployment tool written in Ruby."

Capistrano 3 viết bằng Ruby nhưng có thể sử dụng để deploy các ứng dụng được viết bằng bất cứ ngôn ngữ nào thông qua SSH.

Deploy thường tốn khá nhiều thời gian vì phụ thuộc vào rất nhiều điều kiện:

• Các yếu tố cấu thành nên một ứng dụng (ngôn ngữ lập trình, framework, middleware, ...)
• Môi trường và quy mô deploy
• Thời hạn cho phép deploy
• Giá thành

Đơn cử, bạn thử tưởng tượng ứng dụng của bạn cần được deploy lên 100 servers. Trong trường hợp thời gian deploy bị giới hạn, bạn có thể dùng tay để deploy (?)

Capistrano 3 giúp bạn triển khai ứng dụng đến nhiều server cùng một lúc chỉ bằng việc thực hiện trình tự các command đã được xây dựng sẵn theo kịch bản Capistrano cho phép bạn sao chép mã từ (SVN hoặc Git) đến nhiều server cùng 1 lúc thông qua SSH, và thực hiện chức năng trước và sau khi deploy như kiểm tra thông tin của file config, đổi tên tập tin, chạy di chuyển cơ sở dữ liệu, kiểm tra log ... một cách tự động hóa chỉ bằng việc thực hiện một số câu lệnh cap được chuẩn bị.

Đầu tiên chúng ta cùng tìm hiểu các khái niệm thuật ngữ và mô hình cơ bản của capistrano 3:

Capistrano

Capistrano được cấu thành từ các thành phần sau:

• Cap command
• Capistrano library
• Deploy task default (template)

Đầu tiên chúng ta sử dụng library và template default để viết ra file setting, sau đó chúng thực hiện chạy các file này bằng command cap. Từ đó trở đi chúng ta chỉ việc gọi các command cap này, ứng dụng sẽ được deploy hoặc thực hiện các câu lệnh monitor trên server một cách tự động hoá.

Library

• Ruby Library
• Capistrano extension

File setting

• config/deploy.rb: chứa các thông tin và các task chung
• config/deploy/[stage_name].rb: tên stage thực hiện deploy: production, staging, test...

Host

• Local
• Server

Dưới đây chúng ta sẽ lần lượt đi cài đặt và cấu hình file

1. Ruby programming basic để có thể viết được kịch bản (Task) thực hiện nhiệm vụ deploy
2. Install:

• rbenv
• git
• ruby
• bundler

1. Chuẩn bị server ảo để deploy lên:

• Cài đặt vagrant
• OS demo: Ubuntu 12.04 LTS
• Thiết lập SSH

framgiavn@Mutat-3 ~/Documents> vagrant up
Bringing machine 'default' up with 'virtualbox' provider...
==> default: Checking if box 'hashicorp/precise32' is up to date...
==> default: VirtualBox VM is already running.
framgiavn@Mutat-3 ~/Documents> vagrant ssh
Welcome to Ubuntu 12.04 LTS (GNU/Linux 3.2.0-23-generic-pae i686)

 * Documentation:  https://help.ubuntu.com/
New release '14.04.2 LTS' available.
Run 'do-release-upgrade' to upgrade to it.
Welcome to your Vagrant-built virtual machine.
Last login: Fri Sep 14 06:22:31 2012 from 10.0.2.2
vagrant@precise32:~$

• Câu lệnh install: sudo gem install capistrano
• Kiểm tra version :cap -v

framgiavn@Mutat-3 ~/D/Cap3> cap -v
Capistrano Version: 3.4.0 (Rake Version: 10.4.2)
framgiavn@Mutat-3 ~/D/Cap3>

Sinh ra template cho các file setting:

cap install [STAGES=stage_name1[,stage_name2,...]]

framgiavn@Mutat-3 ~/D/Cap3> cap install STAGES=local,staging,production

Các file template được sinh ra:

framgiavn@Mutat-3 ~/D/Cap3> tree
.
├── Capfile
├── config
│   ├── deploy
│   │   ├── local.rb
│   │   ├── production.rb
│   │   └── staging.rb
│   └── deploy.rb
└── lib
    └── capistrano
        └── tasks

5 directories, 5 files

Như đã nói qua về mô hình của capistrano 3 ở trên, bây giờ chúng ta lần lượt đi tìm hiểu và viết task cho các file config.

Cụ thể trong demo này tôi sẽ viết file thực hiện deploy từ môi trường local, tên file là config/deploy/local.rb.

Cần thiết lập các thông tin sau ở file config/deploy/local.rb:

• stage
• host name
• server role
• login user
• ssh
• other

# coding: utf-8

# stage information
set :stage, :local

# servers information
server "127.0.0.1", user:'vagrant', roles: %w{app active}
# You can add more server here

# fetch(:default_env).merge!(rails_env: :web)

# project directory
set :deploy_to, "/var/www/july"

# app directory
set :app_dir, "july"

# log directory(Apache)
set :httpd_log, "/var/log/httpd/80"

Là file cấu hình các thông tin chung của các stage:

• Tên ứng dụng
• Tên repository
• SCM
• Task

# coding: utf-8

set :application, "july"
set :repo_url, "git@github.com:LeThiNgoc/july.git"

# Default branch is :master
# ask :branch, proc { `git rev-parse --abbrev-ref HEAD`.chomp }.call
set :branch, "master"

# Default deploy_to directory is /var/www/my_app
# set :deploy_to, '/var/www/my_app'

# Default value for :scm is :git
set :scm, :git

# Default value for :format is :pretty
# set :format, :pretty

# Default value for :log_level is :debug
set :log_level, :debug

# Default value for :pty is false
set :pty, true

# Default value for :linked_files is []
set :linked_files, %w{app/config/maintenance-ini.php}

# Default value for linked_dirs is []
set :linked_dirs, %w{app/storage/logs app/storage/cache app/storage/views app/storage/meta app/storage/sessions}

# Default value for default_env is {}
set :default_env, { path: "/usr/local/rbenv/shims:/usr/local/rbenv/bin:$PATH" }

# Default value for keep_releases is 5
set :keep_releases, 5

# default ssh option
set :ssh_options, {
	keys: %w(~/.ssh/id_rsa),
	forward_agent: false,
	auth_methods: %w(publickey),
	user: "vagrant",
    port: 2222,
#	passphrase: nil
}

lib/capistrano/tasks/deploy.rake định nghĩa task thực hiện kịch bản deploy:

# coding: utf-8

namespace :deploy do

	desc "check before execute"
	task :check_deploy do
		on release_roles :all do |host|
			begin
				# check conect
				execute :echo, ""#{host}""
			rescue
				# remove stand server from role
				unless fetch(:filter)
					set :filter, :roles => %w{active etc}
				end
			end
		end
	end
	before "deploy:check", :check_deploy

	desc "after finished pull"
	task :updated do
		invoke "deploy:permission"
	end

	desc "change permission"
	task :permission do
		next unless any? :linked_dirs
		next unless any? :linked_dirs
		on release_roles :all do
			execute :chmod, "777",  linked_dirs(shared_path)
		end
	end

	desc "create shared file"
	task :init_link do
		next unless any? :linked_files
		on release_roles :all do |host|
			linked_files(shared_path).each do |file|
				if !test "[ -e #{file} ]"
					# create shared file
					execute :touch, file
				end
			end
		end
	end
	before "deploy:check:linked_files", :init_link

	desc "check maintenance mode"
	task :maintenance do
		next unless any? :linked_files
		on release_roles :all do |host|
			fetch(:linked_files).each do |file|
				source = release_path.join(file)
				target = shared_path.join(file)
				original = "#{target}.org"
				unless test "[ -L #{target} ]"
					if test "[ -s #{target} ]"
						begin
							# check maintenance mode
							execute :grep, "-E", '""enabled" => true"', target
						rescue
							# update if it is not maintenane mode
							execute :cp, source, target
						end
					else
						# if the file doesn't exist then copy it
						execute :cp, source, target
					end
					# source file
					execute :cp, source, original
				end
			end
		end
	end
	before "deploy:symlink:shared", :maintenance

	task "delete achived file after "
	task :after_rollback do
		on release_roles(:all) do
			# delete achived file after rollback
			archive_release = deploy_path.join("rolled-back-release-*.tar.gz")
			execute :rm, '-f', archive_release
		end
	end
	after "deploy:cleanup_rollback", :after_rollback
end

• Sử dụng command sau để deploy: cap [tên_stage] deploy

framgiavn@Mutat-3 ~/D/Cap3> cap local deploy
INFO [158fb16d] Running /usr/bin/env echo "127.0.0.1" as vagrant@127.0.0.1
DEBUG [158fb16d] Command: /usr/bin/env echo "127.0.0.1"
DEBUG [158fb16d] 	127.0.0.1
INFO [158fb16d] Finished in 4.599 seconds with exit status 0 (successful).
INFO [4ae68589] Running /usr/bin/env mkdir -p /tmp/july/ as vagrant@127.0.0.1
DEBUG [4ae68589] Command: /usr/bin/env mkdir -p /tmp/july/
INFO [4ae68589] Finished in 0.004 seconds with exit status 0 (successful).
DEBUG Uploading /tmp/july/git-ssh.sh 0.0%
INFO Uploading /tmp/july/git-ssh.sh 100.0%
INFO [c3e369b2] Running /usr/bin/env chmod +x /tmp/july/git-ssh.sh as vagrant@127.0.0.1
DEBUG [c3e369b2] Command: /usr/bin/env chmod +x /tmp/july/git-ssh.sh
INFO [c3e369b2] Finished in 0.004 seconds with exit status 0 (successful).
INFO [eb36bfa6] Running /usr/bin/env git ls-remote --heads git@github.com:LeThiNgoc/july.git as vagrant@127.0.0.1
DEBUG [eb36bfa6] Command: ( GIT_ASKPASS=/bin/echo GIT_SSH=/tmp/july/git-ssh.sh /usr/bin/env git ls-remote --heads git@github.com:LeThiNgoc/july.git )
DEBUG [eb36bfa6] 	Warning: Permanently added the RSA host key for IP address '192.30.252.129' to the list of known hosts.
DEBUG [eb36bfa6]
DEBUG [eb36bfa6] 	6c9ecc4b9366bd440ebcc9453f031f1b600264f3
DEBUG [eb36bfa6]
DEBUG [eb36bfa6] 	refs/heads/master
DEBUG [eb36bfa6]
INFO [eb36bfa6] Finished in 3.507 seconds with exit status 0 (successful).
INFO [bb5a6897] Running /usr/bin/env mkdir -p /var/www/july/shared /var/www/july/releases as vagrant@127.0.0.1
DEBUG [bb5a6897] Command: /usr/bin/env mkdir -p /var/www/july/shared /var/www/july/releases
INFO [bb5a6897] Finished in 0.005 seconds with exit status 0 (successful).
INFO [adc31a47] Running /usr/bin/env mkdir -p /var/www/july/shared/app/storage/logs /var/www/july/shared/app/storage/cache /var/www/july/shared/app/storage/views /var/www/july/shared/app/storage/meta /var/www/july/shared/app/storage/sessions as vagrant@127.0.0.1
DEBUG [adc31a47] Command: /usr/bin/env mkdir -p /var/www/july/shared/app/storage/logs /var/www/july/shared/app/storage/cache /var/www/july/shared/app/storage/views /var/www/july/shared/app/storage/meta /var/www/july/shared/app/storage/sessions
INFO [adc31a47] Finished in 0.005 seconds with exit status 0 (successful).
INFO [00a63632] Running /usr/bin/env mkdir -p /var/www/july/shared/app/config as vagrant@127.0.0.1
DEBUG [00a63632] Command: /usr/bin/env mkdir -p /var/www/july/shared/app/config
INFO [00a63632] Finished in 0.004 seconds with exit status 0 (successful).
DEBUG [dde727cb] Running /usr/bin/env [ -e /var/www/july/shared/app/config/maintenance-ini.php ] as vagrant@127.0.0.1
DEBUG [dde727cb] Command: [ -e /var/www/july/shared/app/config/maintenance-ini.php ]
DEBUG [dde727cb] Finished in 0.003 seconds with exit status 1 (failed).
INFO [1511d589] Running /usr/bin/env touch /var/www/july/shared/app/config/maintenance-ini.php as vagrant@127.0.0.1
DEBUG [1511d589] Command: /usr/bin/env touch /var/www/july/shared/app/config/maintenance-ini.php
INFO [1511d589] Finished in 0.005 seconds with exit status 0 (successful).
DEBUG [aac6edf7] Running /usr/bin/env [ -f /var/www/july/shared/app/config/maintenance-ini.php ] as vagrant@127.0.0.1
DEBUG [aac6edf7] Command: [ -f /var/www/july/shared/app/config/maintenance-ini.php ]
DEBUG [aac6edf7] Finished in 0.003 seconds with exit status 0 (successful).
DEBUG [54bc5044] Running /usr/bin/env [ -f /var/www/july/current/REVISION ] as vagrant@127.0.0.1
DEBUG [54bc5044] Command: [ -f /var/www/july/current/REVISION ]
DEBUG [54bc5044] Finished in 0.006 seconds with exit status 1 (failed).
DEBUG [3011d834] Running /usr/bin/env [ -f /var/www/july/repo/HEAD ] as vagrant@127.0.0.1
DEBUG [3011d834] Command: [ -f /var/www/july/repo/HEAD ]
DEBUG [3011d834] Finished in 0.004 seconds with exit status 1 (failed).
DEBUG [3cdbdb4c] Running /usr/bin/env if test ! -d /var/www/july; then echo "Directory does not exist '/var/www/july'" 1>&2; false; fi as vagrant@127.0.0.1
DEBUG [3cdbdb4c] Command: if test ! -d /var/www/july; then echo "Directory does not exist '/var/www/july'" 1>&2; false; fi
DEBUG [3cdbdb4c] Finished in 0.004 seconds with exit status 0 (successful).
INFO [be6a627f] Running /usr/bin/env git clone --mirror git@github.com:LeThiNgoc/july.git /var/www/july/repo as vagrant@127.0.0.1
DEBUG [be6a627f] Command: cd /var/www/july && ( GIT_ASKPASS=/bin/echo GIT_SSH=/tmp/july/git-ssh.sh /usr/bin/env git clone --mirror git@github.com:LeThiNgoc/july.git /var/www/july/repo )
DEBUG [be6a627f] 	Cloning into bare repository '/var/www/july/repo'...
DEBUG [be6a627f]
DEBUG [be6a627f] 	remote: Counting objects: 83, done.[K
DEBUG [be6a627f]
DEBUG [be6a627f] 	remote: Compressing objects:   1% (1/64)   [K
DEBUG [be6a627f] 	remote: Compressing objects:   3% (2/64)   [K
DEBUG [be6a627f] 	remote: Compressing objects:   4% (3/64)   [K
...
INFO [be6a627f] Finished in 4.409 seconds with exit status 0 (successful).
DEBUG [97464c83] Running /usr/bin/env if test ! -d /var/www/july/repo; then echo "Directory does not exist '/var/www/july/repo'" 1>&2; false; fi as vagrant@127.0.0.1
DEBUG [97464c83] Command: if test ! -d /var/www/july/repo; then echo "Directory does not exist '/var/www/july/repo'" 1>&2; false; fi
DEBUG [97464c83] Finished in 0.003 seconds with exit status 0 (successful).
INFO [759e31e2] Running /usr/bin/env git remote update as vagrant@127.0.0.1
DEBUG [759e31e2] Command: cd /var/www/july/repo && ( GIT_ASKPASS=/bin/echo GIT_SSH=/tmp/july/git-ssh.sh /usr/bin/env git remote update )
DEBUG [759e31e2] 	Fetching origin
INFO [759e31e2] Finished in 3.658 seconds with exit status 0 (successful).
DEBUG [a0eb9699] Running /usr/bin/env if test ! -d /var/www/july/repo; then echo "Directory does not exist '/var/www/july/repo'" 1>&2; false; fi as vagrant@127.0.0.1
DEBUG [a0eb9699] Command: if test ! -d /var/www/july/repo; then echo "Directory does not exist '/var/www/july/repo'" 1>&2; false; fi
DEBUG [a0eb9699] Finished in 0.004 seconds with exit status 0 (successful).
INFO [ac880ab5] Running /usr/bin/env mkdir -p /var/www/july/releases/20150728023458 as vagrant@127.0.0.1
DEBUG [ac880ab5] Command: cd /var/www/july/repo && ( GIT_ASKPASS=/bin/echo GIT_SSH=/tmp/july/git-ssh.sh /usr/bin/env mkdir -p /var/www/july/releases/20150728023458 )
INFO [ac880ab5] Finished in 0.004 seconds with exit status 0 (successful).
INFO [959992b1] Running /usr/bin/env git archive master | tar -x -f - -C /var/www/july/releases/20150728023458 as vagrant@127.0.0.1
DEBUG [959992b1] Command: cd /var/www/july/repo && ( GIT_ASKPASS=/bin/echo GIT_SSH=/tmp/july/git-ssh.sh /usr/bin/env git archive master | tar -x -f - -C /var/www/july/releases/20150728023458 )
INFO [959992b1] Finished in 0.009 seconds with exit status 0 (successful).
DEBUG [09c1b589] Running /usr/bin/env if test ! -d /var/www/july/repo; then echo "Directory does not exist '/var/www/july/repo'" 1>&2; false; fi as vagrant@127.0.0.1
DEBUG [09c1b589] Command: if test ! -d /var/www/july/repo; then echo "Directory does not exist '/var/www/july/repo'" 1>&2; false; fi
DEBUG [09c1b589] Finished in 0.009 seconds with exit status 0 (successful).
DEBUG [1974f221] Running /usr/bin/env git rev-list --max-count=1 --abbrev-commit master as vagrant@127.0.0.1
DEBUG [1974f221] Command: cd /var/www/july/repo && ( GIT_ASKPASS=/bin/echo GIT_SSH=/tmp/july/git-ssh.sh /usr/bin/env git rev-list --max-count=1 --abbrev-commit master )
DEBUG [1974f221] 	6c9ecc4
DEBUG [1974f221]
DEBUG [1974f221] Finished in 0.007 seconds with exit status 0 (successful).
DEBUG [5e97e4bf] Running /usr/bin/env if test ! -d /var/www/july/releases/20150728023458; then echo "Directory does not exist '/var/www/july/releases/20150728023458'" 1>&2; false; fi as vagrant@127.0.0.1
DEBUG [5e97e4bf] Command: if test ! -d /var/www/july/releases/20150728023458; then echo "Directory does not exist '/var/www/july/releases/20150728023458'" 1>&2; false; fi
DEBUG [5e97e4bf] Finished in 0.005 seconds with exit status 0 (successful).
INFO [09986b70] Running /usr/bin/env echo "6c9ecc4" >> REVISION as vagrant@127.0.0.1
DEBUG [09986b70] Command: cd /var/www/july/releases/20150728023458 && /usr/bin/env echo "6c9ecc4" >> REVISION
INFO [09986b70] Finished in 0.011 seconds with exit status 0 (successful).
DEBUG [b64153a7] Running /usr/bin/env [ -L /var/www/july/shared/app/config/maintenance-ini.php ] as vagrant@127.0.0.1
DEBUG [b64153a7] Command: [ -L /var/www/july/shared/app/config/maintenance-ini.php ]
DEBUG [b64153a7] Finished in 0.006 seconds with exit status 1 (failed).
DEBUG [5697cd57] Running /usr/bin/env [ -s /var/www/july/shared/app/config/maintenance-ini.php ] as vagrant@127.0.0.1
DEBUG [5697cd57] Command: [ -s /var/www/july/shared/app/config/maintenance-ini.php ]
DEBUG [5697cd57] Finished in 0.005 seconds with exit status 1 (failed).
INFO [4e1054f2] Running /usr/bin/env cp /var/www/july/releases/20150728023458/app/config/maintenance-ini.php /var/www/july/shared/app/config/maintenance-ini.php as vagrant@127.0.0.1
DEBUG [4e1054f2] Command: /usr/bin/env cp /var/www/july/releases/20150728023458/app/config/maintenance-ini.php /var/www/july/shared/app/config/maintenance-ini.php
INFO [4e1054f2] Finished in 0.006 seconds with exit status 0 (successful).
INFO [0f275757] Running /usr/bin/env cp /var/www/july/releases/20150728023458/app/config/maintenance-ini.php /var/www/july/shared/app/config/maintenance-ini.php.org as vagrant@127.0.0.1
DEBUG [0f275757] Command: /usr/bin/env cp /var/www/july/releases/20150728023458/app/config/maintenance-ini.php /var/www/july/shared/app/config/maintenance-ini.php.org
INFO [0f275757] Finished in 0.005 seconds with exit status 0 (successful).
INFO [78af78f2] Running /usr/bin/env mkdir -p /var/www/july/releases/20150728023458/app/config as vagrant@127.0.0.1
DEBUG [78af78f2] Command: /usr/bin/env mkdir -p /var/www/july/releases/20150728023458/app/config
INFO [78af78f2] Finished in 0.005 seconds with exit status 0 (successful).
DEBUG [e4ee925c] Running /usr/bin/env [ -L /var/www/july/releases/20150728023458/app/config/maintenance-ini.php ] as vagrant@127.0.0.1
DEBUG [e4ee925c] Command: [ -L /var/www/july/releases/20150728023458/app/config/maintenance-ini.php ]
DEBUG [e4ee925c] Finished in 0.006 seconds with exit status 1 (failed).
DEBUG [9072b0ce] Running /usr/bin/env [ -f /var/www/july/releases/20150728023458/app/config/maintenance-ini.php ] as vagrant@127.0.0.1
DEBUG [9072b0ce] Command: [ -f /var/www/july/releases/20150728023458/app/config/maintenance-ini.php ]
DEBUG [9072b0ce] Finished in 0.004 seconds with exit status 0 (successful).
INFO [2d628c64] Running /usr/bin/env rm /var/www/july/releases/20150728023458/app/config/maintenance-ini.php as vagrant@127.0.0.1
DEBUG [2d628c64] Command: /usr/bin/env rm /var/www/july/releases/20150728023458/app/config/maintenance-ini.php
INFO [2d628c64] Finished in 0.005 seconds with exit status 0 (successful).
INFO [543bb5e3] Running /usr/bin/env ln -s /var/www/july/shared/app/config/maintenance-ini.php /var/www/july/releases/20150728023458/app/config/maintenance-ini.php as vagrant@127.0.0.1
DEBUG [543bb5e3] Command: /usr/bin/env ln -s /var/www/july/shared/app/config/maintenance-ini.php /var/www/july/releases/20150728023458/app/config/maintenance-ini.php
INFO [543bb5e3] Finished in 0.009 seconds with exit status 0 (successful).
INFO [6cb8cd1b] Running /usr/bin/env mkdir -p /var/www/july/releases/20150728023458/app/storage /var/www/july/releases/20150728023458/app/storage /var/www/july/releases/20150728023458/app/storage /var/www/july/releases/20150728023458/app/storage /var/www/july/releases/20150728023458/app/storage as vagrant@127.0.0.1
DEBUG [6cb8cd1b] Command: /usr/bin/env mkdir -p /var/www/july/releases/20150728023458/app/storage /var/www/july/releases/20150728023458/app/storage /var/www/july/releases/20150728023458/app/storage /var/www/july/releases/20150728023458/app/storage /var/www/july/releases/20150728023458/app/storage
INFO [6cb8cd1b] Finished in 0.005 seconds with exit status 0 (successful).
DEBUG [2d6c2341] Running /usr/bin/env [ -L /var/www/july/releases/20150728023458/app/storage/logs ] as vagrant@127.0.0.1
DEBUG [2d6c2341] Command: [ -L /var/www/july/releases/20150728023458/app/storage/logs ]
DEBUG [2d6c2341] Finished in 0.003 seconds with exit status 1 (failed).
DEBUG [f3129564] Running /usr/bin/env [ -d /var/www/july/releases/20150728023458/app/storage/logs ] as vagrant@127.0.0.1
DEBUG [f3129564] Command: [ -d /var/www/july/releases/20150728023458/app/storage/logs ]
DEBUG [f3129564] Finished in 0.003 seconds with exit status 0 (successful).
INFO [10cc746f] Running /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/logs as vagrant@127.0.0.1
DEBUG [10cc746f] Command: /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/logs
INFO [10cc746f] Finished in 0.004 seconds with exit status 0 (successful).
INFO [e0bd1066] Running /usr/bin/env ln -s /var/www/july/shared/app/storage/logs /var/www/july/releases/20150728023458/app/storage/logs as vagrant@127.0.0.1
DEBUG [e0bd1066] Command: /usr/bin/env ln -s /var/www/july/shared/app/storage/logs /var/www/july/releases/20150728023458/app/storage/logs
INFO [e0bd1066] Finished in 0.004 seconds with exit status 0 (successful).
DEBUG [7507d411] Running /usr/bin/env [ -L /var/www/july/releases/20150728023458/app/storage/cache ] as vagrant@127.0.0.1
DEBUG [7507d411] Command: [ -L /var/www/july/releases/20150728023458/app/storage/cache ]
DEBUG [7507d411] Finished in 0.003 seconds with exit status 1 (failed).
DEBUG [5940188b] Running /usr/bin/env [ -d /var/www/july/releases/20150728023458/app/storage/cache ] as vagrant@127.0.0.1
DEBUG [5940188b] Command: [ -d /var/www/july/releases/20150728023458/app/storage/cache ]
DEBUG [5940188b] Finished in 0.005 seconds with exit status 0 (successful).
INFO [808252d5] Running /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/cache as vagrant@127.0.0.1
DEBUG [808252d5] Command: /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/cache
INFO [808252d5] Finished in 0.004 seconds with exit status 0 (successful).
INFO [4ef1f6a9] Running /usr/bin/env ln -s /var/www/july/shared/app/storage/cache /var/www/july/releases/20150728023458/app/storage/cache as vagrant@127.0.0.1
DEBUG [4ef1f6a9] Command: /usr/bin/env ln -s /var/www/july/shared/app/storage/cache /var/www/july/releases/20150728023458/app/storage/cache
INFO [4ef1f6a9] Finished in 0.004 seconds with exit status 0 (successful).
DEBUG [1ceac512] Running /usr/bin/env [ -L /var/www/july/releases/20150728023458/app/storage/views ] as vagrant@127.0.0.1
DEBUG [1ceac512] Command: [ -L /var/www/july/releases/20150728023458/app/storage/views ]
DEBUG [1ceac512] Finished in 0.008 seconds with exit status 1 (failed).
DEBUG [6ad33c88] Running /usr/bin/env [ -d /var/www/july/releases/20150728023458/app/storage/views ] as vagrant@127.0.0.1
DEBUG [6ad33c88] Command: [ -d /var/www/july/releases/20150728023458/app/storage/views ]
DEBUG [6ad33c88] Finished in 0.005 seconds with exit status 0 (successful).
INFO [03a6bdb4] Running /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/views as vagrant@127.0.0.1
DEBUG [03a6bdb4] Command: /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/views
INFO [03a6bdb4] Finished in 0.005 seconds with exit status 0 (successful).
INFO [93b02294] Running /usr/bin/env ln -s /var/www/july/shared/app/storage/views /var/www/july/releases/20150728023458/app/storage/views as vagrant@127.0.0.1
DEBUG [93b02294] Command: /usr/bin/env ln -s /var/www/july/shared/app/storage/views /var/www/july/releases/20150728023458/app/storage/views
INFO [93b02294] Finished in 0.004 seconds with exit status 0 (successful).
DEBUG [e68132b2] Running /usr/bin/env [ -L /var/www/july/releases/20150728023458/app/storage/meta ] as vagrant@127.0.0.1
DEBUG [e68132b2] Command: [ -L /var/www/july/releases/20150728023458/app/storage/meta ]
DEBUG [e68132b2] Finished in 0.004 seconds with exit status 1 (failed).
DEBUG [9ed377bd] Running /usr/bin/env [ -d /var/www/july/releases/20150728023458/app/storage/meta ] as vagrant@127.0.0.1
DEBUG [9ed377bd] Command: [ -d /var/www/july/releases/20150728023458/app/storage/meta ]
DEBUG [9ed377bd] Finished in 0.003 seconds with exit status 0 (successful).
INFO [84ab330c] Running /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/meta as vagrant@127.0.0.1
DEBUG [84ab330c] Command: /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/meta
INFO [84ab330c] Finished in 0.005 seconds with exit status 0 (successful).
INFO [2296fbe6] Running /usr/bin/env ln -s /var/www/july/shared/app/storage/meta /var/www/july/releases/20150728023458/app/storage/meta as vagrant@127.0.0.1
DEBUG [2296fbe6] Command: /usr/bin/env ln -s /var/www/july/shared/app/storage/meta /var/www/july/releases/20150728023458/app/storage/meta
INFO [2296fbe6] Finished in 0.007 seconds with exit status 0 (successful).
DEBUG [5473fa16] Running /usr/bin/env [ -L /var/www/july/releases/20150728023458/app/storage/sessions ] as vagrant@127.0.0.1
DEBUG [5473fa16] Command: [ -L /var/www/july/releases/20150728023458/app/storage/sessions ]
DEBUG [5473fa16] Finished in 0.003 seconds with exit status 1 (failed).
DEBUG [9518ce86] Running /usr/bin/env [ -d /var/www/july/releases/20150728023458/app/storage/sessions ] as vagrant@127.0.0.1
DEBUG [9518ce86] Command: [ -d /var/www/july/releases/20150728023458/app/storage/sessions ]
DEBUG [9518ce86] Finished in 0.003 seconds with exit status 0 (successful).
INFO [aa0fa9d2] Running /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/sessions as vagrant@127.0.0.1
DEBUG [aa0fa9d2] Command: /usr/bin/env rm -rf /var/www/july/releases/20150728023458/app/storage/sessions
INFO [aa0fa9d2] Finished in 0.006 seconds with exit status 0 (successful).
INFO [f930de48] Running /usr/bin/env ln -s /var/www/july/shared/app/storage/sessions /var/www/july/releases/20150728023458/app/storage/sessions as vagrant@127.0.0.1
DEBUG [f930de48] Command: /usr/bin/env ln -s /var/www/july/shared/app/storage/sessions /var/www/july/releases/20150728023458/app/storage/sessions
INFO [f930de48] Finished in 0.008 seconds with exit status 0 (successful).
INFO [6b4eb814] Running /usr/bin/env chmod 777 /var/www/july/shared/app/storage/logs /var/www/july/shared/app/storage/cache /var/www/july/shared/app/storage/views /var/www/july/shared/app/storage/meta /var/www/july/shared/app/storage/sessions as vagrant@127.0.0.1
DEBUG [6b4eb814] Command: /usr/bin/env chmod 777 /var/www/july/shared/app/storage/logs /var/www/july/shared/app/storage/cache /var/www/july/shared/app/storage/views /var/www/july/shared/app/storage/meta /var/www/july/shared/app/storage/sessions
INFO [6b4eb814] Finished in 0.005 seconds with exit status 0 (successful).
INFO [e740daab] Running /usr/bin/env ln -s /var/www/july/releases/20150728023458 /var/www/july/releases/current as vagrant@127.0.0.1
DEBUG [e740daab] Command: /usr/bin/env ln -s /var/www/july/releases/20150728023458 /var/www/july/releases/current
INFO [e740daab] Finished in 0.009 seconds with exit status 0 (successful).
INFO [420691b1] Running /usr/bin/env mv /var/www/july/releases/current /var/www/july as vagrant@127.0.0.1
DEBUG [420691b1] Command: /usr/bin/env mv /var/www/july/releases/current /var/www/july
INFO [420691b1] Finished in 0.004 seconds with exit status 0 (successful).
DEBUG [0e4ea69e] Running /usr/bin/env ls -xtr /var/www/july/releases as vagrant@127.0.0.1
DEBUG [0e4ea69e] Command: /usr/bin/env ls -xtr /var/www/july/releases
DEBUG [0e4ea69e] 	20150728023458
DEBUG [0e4ea69e] Finished in 0.005 seconds with exit status 0 (successful).
DEBUG [e4c54d1a] Running /usr/bin/env if test ! -d /var/www/july/releases; then echo "Directory does not exist '/var/www/july/releases'" 1>&2; false; fi as vagrant@127.0.0.1
DEBUG [e4c54d1a] Command: if test ! -d /var/www/july/releases; then echo "Directory does not exist '/var/www/july/releases'" 1>&2; false; fi
DEBUG [e4c54d1a] Finished in 0.005 seconds with exit status 0 (successful).
INFO [c8d0b5a1] Running /usr/bin/env echo "Branch master (at 6c9ecc4) deployed as release 20150728023458 by framgiavn" >> /var/www/july/revisions.log as vagrant@127.0.0.1
DEBUG [c8d0b5a1] Command: echo "Branch master (at 6c9ecc4) deployed as release 20150728023458 by framgiavn" >> /var/www/july/revisions.log
INFO [c8d0b5a1] Finished in 0.004 seconds with exit status 0 (successful).

Trên đây là demo nhỏ về việc sử dụng capistrano 3 để deploy một ứng dụng. Ngoài ra chúng ta hoàn toàn có thể viết task để thao tác với server như start/stop maintenance, start/stop/restart apache, lấy log... (Chúng ta cùng tìm hiểu trong lần tiếp theo).

http://capistranorb.com/

https://www.digitalocean.com/community/tutorials/how-to-use-capistrano-to-automate-deployments-getting-started