Capistrano killing assets:precompile

Question

I'm trying to deploy my application and I keep getting

*** [err :: xxx.xxx.xx.xxx] bash: line 1:  9953 Killed                  bundle exec rake RAILS_ENV=production RAILS_GROUPS=assets assets:precompile

I think the issue is that the process is taking too long. There are no errors in the logs and top didn't show anything abnormal. What I did manage to get out of the log is that the process that it's killing seems to be the application.js compilation.

When I ran rake assets:precompile locally, there were no errors/warnings.

Can I extend the length that capistrano waits before killing the process? Is that actually the problem? Where else can I look?

Update

when running

bundle exec rake assets:precompile RAILS_ENV=production RAILS_GROUPS=assets --trace

I get the following output

** Invoke assets:precompile (first_time)
** Execute assets:precompile
** Invoke assets:precompile:all (first_time)
** Execute assets:precompile:all
** Invoke assets:precompile:primary (first_time)
** Invoke assets:environment (first_time)
** Execute assets:environment
** Invoke tmp:cache:clear (first_time)
** Execute tmp:cache:clear
** Execute assets:precompile:primary
Killed

when I run

bundle exec rake assets:precompile RAILS_ENV=production --trace

I get

** Execute assets:precompile

.../.rvm/rubies/ruby-1.9.3-p374/bin/ruby path/to/app/production/shared/bundle/ruby/1.9.1/bin/rake assets:precompile:all RAILS_ENV=production RAILS_GROUPS=assets --trace

** Invoke assets:precompile:all (first_time)

** Execute assets:precompile:all

** Invoke assets:precompile:primary (first_time)

** Invoke assets:environment (first_time)

** Execute assets:environment

** Invoke tmp:cache:clear (first_time)

** Execute tmp:cache:clear

** Execute assets:precompile:primary

rake aborted!

Command failed with status (): [/home/user/.rvm/rubies/ruby-1.9.3-p374...]

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/file_utils.rb:53:in `block in create_shell_runner'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/file_utils.rb:45:in `call'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/file_utils.rb:45:in `sh'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/file_utils_ext.rb:40:in `sh'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/file_utils.rb:80:in `ruby'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/file_utils_ext.rb:40:in `ruby'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/actionpack-3.2.11/lib/sprockets/assets.rake:12:in `ruby_rake_task'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/actionpack-3.2.11/lib/sprockets/assets.rake:21:in `invoke_or_reboot_rake_task'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/actionpack-3.2.11/lib/sprockets/assets.rake:29:in `block (2 levels) in <top (required)>'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:228:in `call'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:228:in `block in execute'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:223:in `each'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:223:in `execute'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:166:in `block in invoke_with_call_chain'

/home/user/.rvm/rubies/ruby-1.9.3-p374/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:159:in `invoke_with_call_chain'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:152:in `invoke'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:143:in `invoke_task'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:101:in `block (2 levels) in top_level'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:101:in `each'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:101:in `block in top_level'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:110:in `run_with_threads'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:95:in `top_level'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:73:in `block in run'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:160:in `standard_exception_handling'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:70:in `run'

path/to/app/production/shared/bundle/ruby/1.9.1/gems/rake-10.0.3/bin/rake:33:in `<top (required)>'

path/to/app/production/shared/bundle/ruby/1.9.1/bin/rake:23:in `load'

path/to/app/production/shared/bundle/ruby/1.9.1/bin/rake:23:in `<main>'

Tasks: TOP => assets:precompile

This doesn't happen in the staging directory. I feel like it's staring me in the face

Answer 1

So I think our problem was that bootstrap-sass was part of the asset precompilation. So it was blowing up all the css, and then compiling it all down. When this is combined with lots of sass/css, the process uses tons of memory, and the OS kills it. After much research, I came across a pretty decent solution. Compile locally, compress it, upload it, decompress it on the server, symlink it on the server, and then delete all the extra files that were created (local assets/compressed files).

Here's the script

namespace :deploy do
  namespace :assets do

    task :precompile, :roles => :web do
      from = source.next_revision(current_revision)
      if capture("cd #{latest_release} && #{source.local.log(from)} vendor/assets/ lib/assets/ app/assets/ | wc -l").to_i > 0
        run_locally("RAILS_ENV=#{rails_env} rake assets:clean && RAILS_ENV=#{rails_env} rake assets:precompile")
        run_locally "cd public && tar -jcf assets.tar.bz2 assets"
        top.upload "public/assets.tar.bz2", "#{shared_path}", :via => :scp
        run "cd #{shared_path} && tar -jxf assets.tar.bz2 && rm assets.tar.bz2"
        run_locally "rm public/assets.tar.bz2"
        run_locally("rake assets:clean")
      else
        logger.info "Skipping asset precompilation because there were no asset changes"
      end
    end

    task :symlink, roles: :web do
      run ("rm -rf #{latest_release}/public/assets &&
            mkdir -p #{latest_release}/public &&
            mkdir -p #{shared_path}/assets &&
            ln -s #{shared_path}/assets #{latest_release}/public/assets")
    end
  end

  # other stuff...

end

Here's where I found the script. It provides a better explanation

Edit:

There was an issue with newer rails deployments. I'm not sure the exact version, but it seemed to affect rails 4. The assets need to specify what environment they are being compiled for, otherwise the production/staging environments won't find them.