我正在部署一个简单的Rails应用程序到这个小型ubuntu precise64服务器设置:
* 1 web服务器运行nginx
* 2个应用服务器运行unicorn
postgresql
我的服务器配备了Puppet，我正在使用capistrano推送应用程序。
My Capfile
load 'deploy'
# Uncomment if you are using Rails' asset pipeline
load 'deploy/assets'
load 'config/deploy' # remove this line to skip loading any of the default tasks
部署。Rb文件超级简单
# Execute "bundle install" after deploy, but only when really needed
require "bundler/capistrano"
# Name of the application in scm (GIT)
set :application, "devops-test-app"
set :repository, "https://github.com/geoffroymontel/devops-test-app.git"
set :scm, :git
set :deploy_to, "/var/www/#{application}"
# server there the web server is running (nginx)
role :web, "172.16.0.2"
# server there the db is running
# This is where Rails migrations will run
role :db, "172.16.0.3", :primary => true
# servers there the app servers are running (unicorn)
role :app, "172.16.0.4", "172.16.0.5"
set :rails_env, :production
# user on the server
set :user, "deployer"
set :use_sudo, false
namespace :deploy do
task :start, :roles => :app, :except => { :no_release => true } do
run "service unicorn_#{application} start"
end
task :stop, :roles => :app, :except => { :no_release => true } do
run "service unicorn_#{application} stop"
end
task :restart, :roles => :app, :except => { :no_release => true } do
run "service unicorn_#{application} restart"
end
task :copy_in_database_yml do
run "cp #{shared_path}/config/database.yml #{latest_release}/config/"
end
# Precompile assets
# I have to precompile the assets on the app servers too, and I don't really know why...
# namespace :assets do
# task :precompile, :roles => [:web, :app], :except => { :no_release => true } do
# run %Q{cd #{latest_release} && #{rake} RAILS_ENV=#{rails_env} #{asset_env} assets:precompile}
# end
# end
end
before "deploy:assets:precompile", "deploy:copy_in_database_yml"
如果我不在应用服务器上预编译资源，应用程序就会失败。
$ cap ROLES="app" COMMAND="cat /var/www/devops-test-app/current/log/production.log" invoke
* 2013-05-01 21:43:10 executing `invoke'
* executing "cat /var/www/devops-test-app/current/log/production.log"
servers: ["172.16.0.4", "172.16.0.5"]
[172.16.0.5] executing command
** [out :: 172.16.0.5] Connecting to database specified by database.yml
** [out :: 172.16.0.5] Connecting to database specified by database.yml
** [out :: 172.16.0.5] Started GET "/posts" for 172.16.0.2 at 2013-05-01 19:42:10 +0000
** [out :: 172.16.0.5] Processing by PostsController#index as HTML
** [out :: 172.16.0.5] Rendered posts/index.html.erb within layouts/application (25.7ms)
** [out :: 172.16.0.5] Completed 500 Internal Server Error in 122ms
** [out :: 172.16.0.5]
** [out :: 172.16.0.5] ActionView::Template::Error (application.css isn't precompiled):
** [out :: 172.16.0.5] 2: <html>
** [out :: 172.16.0.5] 3: <head>
** [out :: 172.16.0.5] 4: <title>DevopsTestApp</title>
** [out :: 172.16.0.5] 5: <%= stylesheet_link_tag "application", :media => "all" %>
** [out :: 172.16.0.5] 6: <%= javascript_include_tag "application" %>
** [out :: 172.16.0.5] 7: <%= csrf_meta_tags %>
** [out :: 172.16.0.5] 8: </head>
** [out :: 172.16.0.5] app/views/layouts/application.html.erb:5:in `_app_views_layouts_application_html_erb__677166568443748084_17536100'
** [out :: 172.16.0.5] app/controllers/posts_controller.rb:7:in `index'
如果我取消deploy.rb中注释的行，一切都很好。
为什么??我以为你只需要在web服务器上编译资源，而不是在应用服务器上。
请告诉我为什么:)
Thanks, best regards
Geoffroy
因为，除其他事项外，Rails生成预编译资产的清单，其中包括文件名中文件的散列，然后当您在页面中包含这些资产时使用这些名称。当你说image_url('foo.jpg')时，Rails最终会在源代码中生成foo-b48cf0140bea12734db05ebcdb012f1d265bed84.jpg。
Rails需要知道为这些资产使用什么编译名，所以它必须有manifest，所以预编译需要在应用服务器上完成。
看一下public/assets/manifest.yml -这是Rails需要的文件，以便正确地提供预编译的资源
这是Capistrano中一个已知的bug。
1)评论
load 'deploy/assets'
在你的Capfile .
2)在deploy.rb文件的顶部添加以下行:
set :assets_role, [:web, :app]
load 'deploy/assets'
确保你将Nginx配置为提供静态文件而不触及应用程序服务器。这很可能是没有配置，因此资产存在，但Nginx不为他们服务，并回落到应用程序。