.worker file with `gemfile "Gemfile", "group"` increases remote build time x10 - iron.io

Question

To better manage the required gems across my application, I created a Gemfile group called :iron:
group :default, :iron do
  gem "activerecord", require: 'active_record
  gem 'mysql2'
  gem 'aws-sdk'
  gem 'yajl-ruby'
  gem 'hashie'
  gem 'require_all'
end
This would help consolidate the required gems for iron worker. My .worker file is now as follows:
gemfile '../Gemfile', 'iron'
instead of redundantly listing all the gems individually:
gem "activerecord"
gem 'mysql2'
...
Unfortunately, this increased my remote build time from 1 minute to 10 minutes. The output attempts to include far more gems, seemingly bubbling up nested dependencies:
BEFORE:
------> Creating code package
Found workerfile with path='iron_job.worker'
Detected exec with path='iron_job_bootstrapper.rb' and args='{}'
Merging dir with path='../app/models' and dest=''
Merging dir with path='../lib' and dest=''
Merging file with path='iron.json' and dest=''
Adding ruby gem dependency with name='activerecord' and version='>= 0'
Adding ruby gem dependency with name='mysql2' and version='>= 0'
Adding ruby gem dependency with name='aws-sdk' and version='>= 0'
Adding ruby gem dependency with name='yajl-ruby' and version='>= 0'
Adding ruby gem dependency with name='hashie' and version='>= 0'
Adding ruby gem dependency with name='require_all' and version='>= 0'
AFTER:
------> Creating code package
Found workerfile with path='iron_job.worker'
Detected exec with path='iron_job_bootstrapper.rb' and args='{}'
Merging dir with path='../app/models' and dest=''
Merging dir with path='../lib' and dest=''
Merging file with path='iron.json' and dest=''
Adding ruby gems dependencies from iron group of ../Gemfile
Adding ruby gem dependency with name='i18n' and version='0.6.5'
Adding ruby gem dependency with name='minitest' and version='4.7.5'
Adding ruby gem dependency with name='multi_json' and version='1.8.1'
Adding ruby gem dependency with name='atomic' and version='1.1.14'
Adding ruby gem dependency with name='thread_safe' and version='0.1.3'
Adding ruby gem dependency with name='tzinfo' and version='0.3.37'
Adding ruby gem dependency with name='activesupport' and version='4.0.0'
Adding ruby gem dependency with name='builder' and version='3.1.4'
Adding ruby gem dependency with name='activemodel' and version='4.0.0'
Adding ruby gem dependency with name='activerecord-deprecated_finders' and version='1.0.3'
Adding ruby gem dependency with name='arel' and version='4.0.0'
Adding ruby gem dependency with name='activerecord' and version='4.0.0'
Adding ruby gem dependency with name='json' and version='1.8.0'
Adding ruby gem dependency with name='mini_portile' and version='0.5.1'
Adding ruby gem dependency with name='nokogiri' and version='1.6.0'
Adding ruby gem dependency with name='uuidtools' and version='2.1.4'
Adding ruby gem dependency with name='aws-sdk' and version='1.11.1'
Adding ruby gem dependency with name='bundler' and version='1.3.5'
Adding ruby gem dependency with name='hashie' and version='2.0.5'
Adding ruby gem dependency with name='mysql2' and version='0.3.13'
Adding ruby gem dependency with name='require_all' and version='1.3.1'
Adding ruby gem dependency with name='yajl-ruby' and version='1.1.0'
This output was local, but the time stretched out even more on the IronWorker service because it reinstalls gems more than once (uninstall then reinstalls bundler). The log below has the details.
https://hud.iron.io/tq/projects/5254773dd05880000d000003/tasks/525ee1d9f8953468b927e83f/log
We have since gone back to a .worker file that simply lists out the gems we need rather than invoke gemfile "Gemfile", "iron". Any help on how to use gemfile without reinstalling bundler and have a 10m upload time would be much appreciated!
Thanks.
Edit
Adding full Gemfile. Please note that we have no desire to pull in all the gems on the :default group. That is overkill for our workers. We just want :iron.
Bundler version 1.3.5
source 'https://rubygems.org'
ruby '1.9.3'
gem 'typhoeus' # Only for ruby 1.9.3
gem 'rails', '4.0.0'
gem 'sass-rails', '~> 4.0.0'
gem 'uglifier', '>= 1.3.0'
gem 'coffee-rails', '~> 4.0.0'
gem 'jquery-rails'
gem 'turbolinks'
gem 'haml-rails'
gem 'thin-rails'
gem 'therubyracer'
gem 'less-rails'
gem 'twitter-bootstrap-rails'
gem 'settingslogic'
gem 'iron_worker_ng'
group :default, :iron do
gem "activerecord", require: 'active_record'
gem 'mysql2'
gem 'aws-sdk'
gem 'yajl-ruby'
gem 'require_all'
end
group :doc do
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', require: false
end
group :production, :qa do
gem 'rails_12factor' #for heroku
end
group :development, :test do
gem 'factory_girl_rails'
gem 'ffaker'
gem 'shoulda-matchers'
gem 'pry'
gem 'debugger', '>= 1.6.1'
gem 'pry-debugger'
gem 'pivotal_git_scripts'
gem 'rspec-rails'
gem 'capybara'
gem 'fuubar'
end
group :test do
gem 'database_cleaner'
end
grouped Gemfile:
source 'https://rubygems.org'
ruby '1.9.3'
group :rails do
gem 'typhoeus' # Only for ruby 1.9.3
gem 'rails', '4.0.0'
gem 'sass-rails', '~> 4.0.0'
gem 'uglifier', '>= 1.3.0'
gem 'coffee-rails', '~> 4.0.0'
gem 'jquery-rails'
gem 'turbolinks'
gem 'haml-rails'
gem 'thin-rails'
gem 'therubyracer'
gem 'less-rails'
gem 'twitter-bootstrap-rails'
gem 'settingslogic'
gem 'rack-mini-profiler'
end
group :rails, :iron do
gem "activerecord", require: 'active_record'
gem 'mysql2'
gem 'aws-sdk'
gem 'yajl-ruby'
gem 'require_all'
gem 'hashie'
gem 'iron_worker_ng'
end
group :doc do
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', require: false
end
group :production, :qa do
gem 'rails_12factor' #for heroku
end
group :development, :test do
gem 'factory_girl_rails'
gem 'ffaker'
gem 'shoulda-matchers'
gem 'pry'
gem 'debugger', '>= 1.6.1'
gem 'pry-debugger'
gem 'pivotal_git_scripts'
gem 'rspec-rails'
gem 'capybara'
gem 'fuubar'
end
group :test do
gem 'database_cleaner'
end

Answer 1

IronWorker already announced a "Docker Workflow" and you don't need the .worker file anymore. You just need to install all dependencies locally in docker image reproducing the same environment as running on IronWorker servers. Here you can find a ruby "HelloWorld" example.