Rails 3.2.1，资产在部署时预编译了两次？

Question

我有这个 Capistrano 任务：

namespace :deploy do
  task :precompile, :role => :app do
    run "cd #{release_path}/ && RAILS_ENV=staging bundle exec rake assets:precompile --trace"
  end
end

after "deploy:finalize_update", "deploy:precompile"

我知道有load 'deploy/assets'，但我正试图了解这里发生了什么。

我正在部署到一个 Amazon EC2 m1.small 实例，该实例显然一直有 50% 的 CPU 窃取时间，并通过 top 进行了验证。 这会导致编译资产的时间增加，但请看一下：

    [23.21.xxx.xx] rvm_path=$HOME/.rvm/ $HOME/.rvm/bin/rvm-shell 'ruby-1.9.3-p125' -c 'cd /home/ubuntu/apps/myapp-rails/releases/20120227020245/ && RAILS_ENV=staging bundle exec rake assets:precompile --trace'
 ** [out :: 23.21.xxx.xx] ** Invoke assets:precompile (first_time)
 ** [out :: 23.21.xxx.xx] ** Execute assets:precompile
 ** [out :: 23.21.xxx.xx] /home/ubuntu/.rvm/rubies/ruby-1.9.3-p125/bin/ruby /home/ubuntu/apps/myapp-rails/shared/bundle/ruby/1.9.1/bin/rake assets:precompile:all RAILS_ENV=staging RAILS_GROUPS=assets --trace
 ** [out :: 23.21.xxx.xx] ** Invoke assets:precompile:all (first_time)
 ** [out :: 23.21.xxx.xx] ** Execute assets:precompile:all
 ** [out :: 23.21.xxx.xx] ** Invoke assets:precompile:primary (first_time)
 ** [out :: 23.21.xxx.xx] ** Invoke assets:environment (first_time)
 ** [out :: 23.21.xxx.xx] ** Execute assets:environment
 ** [out :: 23.21.xxx.xx] ** Invoke environment (first_time)
 ** [out :: 23.21.xxx.xx] ** Execute environment
 ** [out :: 23.21.xxx.xx] ** Invoke tmp:cache:clear (first_time)
 ** [out :: 23.21.xxx.xx] ** Execute tmp:cache:clear
 ** [out :: 23.21.xxx.xx] ** Execute assets:precompile:primary
 ** [out :: 23.21.xxx.xx] ** Invoke assets:precompile:nondigest (first_time)
 ** [out :: 23.21.xxx.xx] ** Invoke assets:environment (first_time)
 ** [out :: 23.21.xxx.xx] ** Execute assets:environment
 ** [out :: 23.21.xxx.xx] ** Invoke environment (first_time)
 ** [out :: 23.21.xxx.xx] ** Execute environment
 ** [out :: 23.21.xxx.xx] ** Invoke tmp:cache:clear (first_time)
 ** [out :: 23.21.xxx.xx] ** Execute tmp:cache:clear
 ** [out :: 23.21.xxx.xx] ** Execute assets:precompile:nondigest
    command finished in 958131ms

除了出于某种原因花费在预编译资产上的 疯狂 量之外，我可以说它编译了两次。为什么？

我使用的是 Rails 3.2.1。 有人可以提供一些关于这里发生了什么的见解吗？是故意的吗？

staging.rb

  # Compress JavaScripts and CSS
  config.assets.compress = true

  # Don't fallback to assets pipeline if a precompiled asset is missed
  config.assets.compile = false

  # Generate digests for assets URLs
  config.assets.digest = true

Answer 1

load 'deploy/assets' 在部署的适当部分自动为您预编译资产，因此您无需定义预编译任务。你可以删除你的预编译任务和after "deploy:finalize_update", "deploy:precompile"。

https://github.com/capistrano/capistrano/blob/master/lib/capistrano/recipes/deploy/assets.rb

edit：默认情况下，当您将摘要设置为 true 时，Rails 将创建指纹文件和非指纹文件。它实际上并没有将整个预编译任务运行两次，它只是针对每种情况运行一个任务。

如果您想完全禁用生成非指纹文件，则可以覆盖 assets:precompile:all 任务。

Rake::Task['assets:precompile:all'].clear
namespace :assets do
  namespace :precompile do
    task :all do
      Rake::Task['assets:precompile:primary'].invoke
      # ruby_rake_task("assets:precompile:nondigest", false) if Rails.application.config.assets.digest
    end
  end
end

注释掉的行是这里的第 66 行：

https://github.com/rails/rails/blob/master/actionpack/lib/sprockets/assets.rake