capistrano配置

服务器文件结构 
  myapp/releases
  myapp/current -> releases/20081019001122
  myapp/shared
deploy任务分类
  deploy:update_code
  deploy:symlink_shared
  deploy:symlink
  deploy:restart



set :application, "demo"
set :user, "demo"
set :repository,  "[e-mail]:yang/demo.git"
set :scm, :git
# Or: `accurev`, `bzr`, `cvs`, `darcs`, `git`, `mercurial`, `perforce`, `subversion` or `none`
set :use_sudo, false
set :deploy_via, :remote_cache

server "www.demo", :app, :web, :db, :primary => true

namespace :deploy do
  set :deploy_to, "/home/demo/master"

  desc "Long deploy will update the code migrate the database and restart the servers"
  task :master do
    set :deploy_to, "/home/demo/master"
    set :branch, "master"
    set :env, "production"
   
    transaction do
      update_code
      symlink
      copy_configs
      migrate
    end
   
    restart
  end

  desc "Custom after update code to put production database.yml in place."
  task :copy_configs, :roles => :app do
    run "cp #{deploy_to}/shared/database.yml #{current_path}/config/database.yml"
    run "ln -s #{deploy_to}/shared/recommend_photos #{current_path}/public/recommend_photos"
    run "rm -rf #{current_path}/public/market_info_photos && ln -s #{deploy_to}/shared/market_info_photos #{current_path}/public/market_info_photos"
  # 不需要部署的文件放在share目录里，在current目录使用软链接访问
  end
 
  desc "Rake database"
  task :migrate, :roles => :app,nly => {:primary => true} do
    run "cd #{deploy_to}/current && RAILS_ENV=#{env} rake db:schema:load"
  end
 
  desc "Restart the app server"
  task :restart, :roles => :app do
    run "cd #{deploy_to}/current && touch tmp/restart.txt"
  end
end