Rails + passenger + git + capistrano实现自动化部署

首先要：yum install sudo which #如果有就算了
1,我们需要关心的主要是config/deploy.rb这个文件，我们先来看看程序自动为我们生成了些什么：

[root@master blog]# cat config/deploy.rb
set :application, "set your application name here"
set :repository,  "set your repository location here"
set :scm, :subversion
# Or: `accurev`, `bzr`, `cvs`, `darcs`, `git`, `mercurial`, `perforce`, `subversion` or `none`

role :web, "your web-server here"                          # Your HTTP server, Apache/etc
role :app, "your app-server here"                          # This may be the same as your `Web` server
role :db,  "your primary db-server here", :primary => true # This is where Rails migrations will run
role :db,  "your slave db-server here"

# If you are using Passenger mod_rails uncomment this:
# if you're still using the script/reapear helper you will need
# these http://github.com/rails/irs_process_scripts

# namespace :deploy do
#   task :start do ; end
#   task :stop do ; end
#   task :restart, :roles => :app, :except => { :no_release => true } do
#     run "#{try_sudo} touch #{File.join(current_path,'tmp','restart.txt')}"
#   end

可以看到系统已经提示我们一些基本的设置了
首先,设置application

set :application, "blog" #在这里我给他起名字叫blog,当然这个根据具体情况了

设置repository，我用的是git：

set :repository,  "ssh://[email protected]/usr/local/system/repository/blog.git"
set :scm, :git
set :scm_command, "/usr/local/git/bin/git" #这个也很关键啊，否则会找不到git命令了
#set :scm_passphrase, "xxxx" 没有密码的就不用设置了

接下来就是设置你的server,我的是在同一台机器上面,所以都相同了：

role :web, "www.weekface.info"                     # Your HTTP server, Apache/etc
role :app, "www.weekface.info"                          # This may be the same as your `Web` server
role :db,  "www.weekface.info", :primary => true # This is where Rails migrations will run

再接下来是部署的位置:

set :deploy_to, "/usr/local/system/www/#{application}"

部署的时候是用ssh public key方式连接合服务器，这个在以前的文章中说明过
下面是使用者相关的配置:

set :user, "root"
set :runner, "root"

大部分部署指令会以:user设定的身份去运行,但和启动应用服务器相关的指令会以:runner设置的身份去运行.
最后，由于我用的是passenger,所以来设置一下启动passenger的相关设置吧：

 namespace :deploy do
   task :start do ; end
   task :stop do ; end
   task :restart, :roles => :app, :except => { :no_release => true } do
     run "touch #{File.join(current_path,'tmp','restart.txt')}"
   end
end

2,部署
第一次部署需要运行下面的命令:

cap deploy:setup

报错了:

sh: sudo: command not found
#或者
sudo: sorry, you must have a tty to run sudo

google了一下,可以这样解决:

[root@li96-10 ~]# vim /etc/sudoers
# Disable "ssh hostname sudo <cmd>", because it will show the password in clear.
#         You have to run "ssh -t hostname sudo <cmd>".
#
#Defaults    requiretty #将这行注释掉

继续执行:

[root@master blog]# cap deploy:setup
  * executing `deploy:setup'
  * executing "sudo -p 'sudo password: ' mkdir -p /usr/local/system/www/blog /usr/local/system/www/blog/releases /usr/local/system/www/blog/shared /usr/local/system/www/blog/shared/system /usr/local/system/www/blog/shared/log /usr/local/system/www/blog/shared/pids && sudo -p 'sudo password: ' chmod g+w /usr/local/system/www/blog /usr/local/system/www/blog/releases /usr/local/system/www/blog/shared /usr/local/system/www/blog/shared/system /usr/local/system/www/blog/shared/log /usr/local/system/www/blog/shared/pids"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
    command finished

这个命令会在服务器上配置好相关的目录结构.然后再运行:,以检查目录结构是否配置正确：

[root@master blog]# cap deploy:check
  * executing `deploy:check'
  * executing "test -d /usr/local/system/www/blog/releases"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
    command finished
  * executing "test -w /usr/local/system/www/blog"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
    command finished
  * executing "test -w /usr/local/system/www/blog/releases"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
    command finished
  * executing "which git"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
www.weekface.info: sh: which: command not found

    command finished
The following dependencies failed. Please check them and try again:
--> `git' could not be found in the path (www.weekface.info) #见上面的解决办法:set :scm_command, "/usr/local/git/bin/git"

再试一下:

[root@master blog]# cap deploy:check
  * executing `deploy:check'
  * executing "test -d /usr/local/system/www/blog/releases"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
    command finished
  * executing "test -w /usr/local/system/www/blog"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
    command finished
  * executing "test -w /usr/local/system/www/blog/releases"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
    command finished
  * executing "which /usr/local/git/bin/git"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
    command finished
You appear to have all necessary dependencies installed

这就代表检查成功了!
下面就开始第一次部署：

[root@master blog]# cap deploy:cold
  * executing `deploy:cold'
  * executing `deploy:update'
 ** transaction: start
  * executing `deploy:update_code'
    executing locally: "/usr/local/git/bin/git ls-remote ssh://www.weekface.info/usr/local/system/repository/blog.git HEAD"
  * executing "/usr/local/git/bin/git clone -q ssh://www.weekface.info/usr/local/system/repository/blog.git /usr/local/system/www/blog/releases/20100107141957 && cd /usr/local/system/www/blog/releases/20100107141957 && /usr/local/git/bin/git checkout -q -b deploy a2546709a9109af3d6f098030c2fb7e3acc89b12 && (echo a2546709a9109af3d6f098030c2fb7e3acc89b12 > /usr/local/system/www/blog/releases/20100107141957/REVISION)"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
 ** [www.weekface.info :: err] Host key verification failed. #这里这里
 ** [www.weekface.info :: err] fatal: The remote end hung up unexpectedly
    command finished
*** [deploy:update_code] rolling back
  * executing "rm -rf /usr/local/system/www/blog/releases/20100107141957; true"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
    command finished
failed: "sh -c '/usr/local/git/bin/git clone -q ssh://www.weekface.info/usr/local/system/repository/blog.git /usr/local/system/www/blog/releases/20100107141957 && cd /usr/local/system/www/blog/releases/20100107141957 && /usr/local/git/bin/git checkout -q -b deploy a2546709a9109af3d6f098030c2fb7e3acc89b12 && (echo a2546709a9109af3d6f098030c2fb7e3acc89b12 > /usr/local/system/www/blog/releases/20100107141957/REVISION)'" on www.weekface.info

解决办法是修改config/deploy.rb,加入:

set :branch, 'master'
set :deploy_via, :copy

继续:

[root@master blog]# cap deploy:cold
...
...
* executing "cd /usr/local/system/www/blog/releases/20100107143738; rake RAILS_ENV=production  db:migrate"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
*** [err :: www.weekface.info] sh: rake: command not found
    command finished
failed: "sh -c 'cd /usr/local/system/www/blog/releases/20100107143738; rake RAILS_ENV=production  db:migrate'" on www.weekface.info

google了一下,在config/deploy.rb加入:

set :rake, "/usr/local/system/ruby/rake"

然后再继续:

[root@master blog]# cap deploy:cold
...
...
library: no such file to load -- system_timer #解决办法 : gem install system_timer

呵呵，以后再部署就可以直接用:

cap deploy
如果发生问题要rollback可以用:
cap deploy:rollback

到此为止…睡觉去
Rails启动时有个错:uninitialized constant User::Authentication,结果发现是restful_authentation这个插件目录里是空的，不知道怎么搞的，重新把文件拷贝过去就行了.
接下来还有在deploy.rb文件里自定义一些任务(task)，完成一些其他任务,比如建立public/photos的连结等等:
首先，从git中删除不需要版本控制的文件:
在本机的blog目录下新建文件.gitignore:

config/database.yml
config/environment.rb
public/photos
log
nbproject
*~
*.cache
*.log
*.pid
tmp/**/*

以上这些文件都不需要版本控制,然后push,同时在服务器上要将config/database.yml，config/environment.rb，public/photos/*文件给他复制到shared目录下，并且将这些文件目录从git中删除，一会我们会给他 在部署的时候作link

[root@master blog]# git add .gitignore
[root@master blog]# git commit -am "add .gitignore"
[root@master blog]# git push

编辑deploy.rb文件，加入一下tasks:

 desc "Symlink shared configs and folders on each release."
   task :symlink_shared do
     run "ln -nfs #{shared_path}/config/database.yml #{release_path}/config/database.yml"
     run "ln -nfs #{shared_path}/config/environment.rb #{release_path}/config/environment.rb"
     run "ln -nfs #{shared_path}/public/photos #{release_path}/public/photos"
     #run "export RAILS_ENV=production && #{release_path}/script/workling_client start"
   end
after 'deploy:update_code', 'deploy:symlink_shared'

基本就是这样了，以后还会介绍在实际使用过程中遇到的一些问题：

Rails Error: Unable to access log file. Please ensure that /usr/local/system/www/blog/releases/20100109050547/log/production.log exists and is chmod 0666. The log level has been raised to WARN and the output directed to STDERR until the problem is fixed.

这个问题主要是因为shared/log目录没有可写权限，解决办法:

[root@li96-10 shared]# chmod -R 0666 log

还有一个问题:重启workling时报错:/usr/bin/env: ruby no such file or directory

* executing "cd /usr/local/system/www/blog/releases/20100109062537 && RAILS_ENV=production ./script/workling_client stop"
    servers: ["www.weekface.info"]
    [www.weekface.info] executing command
*** [err :: www.weekface.info] /usr/bin/env: ruby
*** [err :: www.weekface.info] : No such file or directory

原因是找不到ruby，下面是暂时解决办法:

[root@master blog]# vim script/workling_client
#将第一行的 ：#!/usr/bin/env ruby
#修改为: #!/usr/local/system/ruby-1.8.7-p72/bin/ruby
#就是hard code了，呵呵
[root@master blog]# git commit -am "xx"  #然后提交到git

就可以了