加速资产:使用Rails 3.1/3.2 Capistrano部署进行预编译

Question

我的部署速度很慢,至少需要3分钟.部署期间缓慢的Capistrano任务是资产:预编译.这大约占总部署时间的99%.我怎样才能加快速度呢？我应该在我的本地计算机上预编译我的资产并将它们添加到我的git仓库吗？

编辑:添加config.assets.initialize_on_precompile = false到我的application.rb文件,半分钟后删除预编译时间,但它仍然很慢.

Answer 1

我们的想法是,如果您不更改资产,则无需每次都重新编译它们:

这是Ben Curtis建议使用git进行部署的解决方案:

 namespace :deploy do
      namespace :assets do
        task :precompile, :roles => :web, :except => { :no_release => true } do
          from = source.next_revision(current_revision)
          if releases.length <= 1 || capture("cd #{latest_release} && #{source.local.log(from)} vendor/assets/ app/assets/ | wc -l").to_i > 0
            run %Q{cd #{latest_release} && #{rake} RAILS_ENV=#{rails_env} #{asset_env} assets:precompile}
          else
            logger.info "Skipping asset pre-compilation because there were no asset changes"
          end
      end
    end
  end

这是另一种基于资产年龄的方法(https://gist.github.com/2784462):

set :max_asset_age, 2 ## Set asset age in minutes to test modified date against.

after "deploy:finalize_update", "deploy:assets:determine_modified_assets", "deploy:assets:conditionally_precompile"

namespace :deploy do
  namespace :assets do

    desc "Figure out modified assets."
    task :determine_modified_assets, :roles => assets_role, :except => { :no_release => true } do
      set :updated_assets, capture("find #{latest_release}/app/assets -type d -name .git -prune -o -mmin -#{max_asset_age} -type f -print", :except => { :no_release => true }).split
    end

    desc "Remove callback for asset precompiling unless assets were updated in most recent git commit."
    task :conditionally_precompile, :roles => assets_role, :except => { :no_release => true } do
      if(updated_assets.empty?)
        callback = callbacks[:after].find{|c| c.source == "deploy:assets:precompile" }
        callbacks[:after].delete(callback)
        logger.info("Skipping asset precompiling, no updated assets.")
      else
        logger.info("#{updated_assets.length} updated assets. Will precompile.")
      end
    end

  end
end

如果您希望在本地预编译资产,则可以使用此任务:

namespace :deploy do
  namespace :assets do
    desc 'Run the precompile task locally and rsync with shared'
    task :precompile, :roles => :web, :except => { :no_release => true } do
      from = source.next_revision(current_revision)
      if releases.length <= 1 || capture("cd #{latest_release} && #{source.local.log(from)} vendor/assets/ app/assets/ | wc -l").to_i > 0
        %x{bundle exec rake assets:precompile}
        %x{rsync --recursive --times --rsh=ssh --compress --human-readable --progress public/assets #{user}@#{host}:#{shared_path}}
        %x{bundle exec rake assets:clean}
      else
        logger.info 'Skipping asset pre-compilation because there were no asset changes'
      end
    end
  end
end 

另一种有趣的方法可以是使用git钩子.例如,您可以添加此代码以.git/hooks/pre-commit检查资产文件是否存在任何差异,并最终预编译它们并将它们添加到当前提交.

#!/bin/bash

# source rvm and .rvmrc if present
[ -s "$HOME/.rvm/scripts/rvm" ] && . "$HOME/.rvm/scripts/rvm"
[ -s "$PWD/.rvmrc" ] && . "$PWD/.rvmrc"

# precompile assets if any have been updated
if git diff-index --name-only HEAD | egrep '^app/assets' >/dev/null ; then
  echo 'Precompiling assets...'
  rake assets:precompile:all RAILS_ENV=production RAILS_GROUPS=assets
  git add public/assets/*
fi

如果您决定使用此方法,则可能需要更改config/environments/development.rb添加:

config.assets.prefix = '/assets_dev'

因此,在开发过程中,您将无法提供预编译资产.

Answer 2

我刚刚编写了一个gem来解决Rails中的这个问题,称为turbo-sprockets-rails3.它assets:precompile通过仅重新编译已更改的文件来加速您的速度,并且仅编译一次以生成所有资产.它开箱即用于Capistrano,因为您的资产目录在版本之间共享.

这比使用的解决方案更加防弹git log,因为我的补丁分析了资产的来源,即使它们来自宝石.例如,如果更新jquery-rails,将检测到更改application.js,并且仅application.js重新编译.

请注意,我也试图将此补丁合并到Rails 4.0.0,可能还有Rails 3.2.9(参见https://github.com/rails/sprockets-rails/pull/21).但是现在,如果你可以帮我测试一下turbo-sprockets-rails3宝石会很棒,如果你有任何问题请告诉我.