How to make each unicorn worker of my Rails application log to a different file?

Question

How can I make each unicorn worker of my Rails application writting in a different log file ?

The why : problem of mixed log files... In its default configuration, R

Answer 1

add this code to after_fork in unicorn.rb:

#one log per unicorn worker
if log = Rails.logger.instance_values['log']
  ext = File.extname log.path
  new_path =log.path.gsub %r{(.*)(#{Regexp.escape ext})}, "\\1.#{worker.nr}\\2"
  Rails.logger.instance_eval do
    @log.close
    @log= open_log new_path, 'a+'
  end
end