Upgrading to Rails 5.0.0.beta1

What we did to upgrade a small Rails app from Rails 4.2.5 to Rails 5.0.0.beta1.

Now the upgrade is deployed in AWS, here is where we are at:

1. When deploying, remember to change the secret key base to invalidate all sessions. ( or your users will get a nasty 500 error )
2. Temporarily removed NewRelic from the gemfile – it doesn’t  currently support Rails 5.0.0.beta1. (UPDATE: as of 11 Feb NewRelic supports Rails 5.0.0.beta2)
3. Temporarily removed rspec-rails from the gemfile to avoid a deployment error on AWS (ArgumentError while loading rspec-support.gemspec: couldn’t find HOME environment)

Steps to upgrade:

1. We updated the rails gem version and ran bundle update, and upgraded gems including:

   gem ‘nokogiri’, ‘1.6.3.rc1’ upgraded to ‘1.6.8.rc1’
   gem 'newrelic_rpm' temporarily removed unltil support added for Rails 5.0
   gem 'aws-sdk', '1.66.0' upgraded to ‘2.2.7’
   gem 'coffee-rails', '4.0.1' upgraded to '4.1.1'
   gem 'coffee-script-source', '1.8.0' upgraded to '1.10.0'
   gem 'jquery-rails', '4.0.0.beta2' upgraded to '4.0.5'
   gem 'rspec-rails', '~> 3.1.0' upgraded to a git PR not yet released at the time:
   gem 'rspec-rails', :git => 'https://github.com/rspec/rspec-rails.git', :ref => '275905d'
   %w[rspec rspec-core rspec-expectations rspec-mocks rspec-support].each do |lib|
   gem lib, :git => "git://github.com/rspec/#{lib}.git", :branch => 'master'
   end
   

2. On running we got this compile error:

   Solution: You have to use Puma for Rails 5.0 ( for Action Cable ). We were already using it but eventually tracked this down to the out-of-date puma gem version (2.9.1). To fix, specify the correct puma version in your gemfile:

   gem 'puma', '2.15.3'
   

   We also had to remove newrelic_rpm from the gem file because running bundle exec rake db:migrate caused this error:

   rake aborted!
   NameError: wrong constant name [[:error, ["detected unsupported rails version 5.0.0.beta1"], nil]]
   /home/rof/cache/bundler/ruby/2.2.0/gems/newrelic_rpm-3.14.1.311/lib/new_relic/control/class_methods.rb:52:in `const_get'
   

3. Add or update files required for this release:

   rake rails:update
   

   Additions / updates included :

   • config/application.rb
   • config/environments/development.rb, production.rb & test.rb ( carefully merge changes )
   • config/redis
   • config/initializers/active_record_belongs_to_required_by_default.rb
   • config/initializers/application_controller_renderer.rb
   • config/initializers/assets.rb
   • config/initializers/backtrace_silencers.rb
   • config/initializers/callback_terminator.rb
   • config/initializers/cors.rb
   • config/initializers/inflections.rb
   • bin/

4. Test failures: we got 50% failures ( and 1000 DEPRECATION WARNINGs - probably many will be resolved when  rspec is updated. We will aim to get these down to zero again soon. )

   Of the 50% test failures:

   • 358  TypeErrors: can’t dump hash with default proc - all from one single line of code using Rails caching, easily fixed.
   • 93 are NoMethodError: assigns has been extracted to a gem. To continue using it, add gem ‘rails-controller-testing’ to your Gemfile.
   • 42 are NoMethodError: assert_template has been extracted to a gem. To continue using it, add gem ‘rails-controller-testing’ to your Gemfile.
   • 21 are NoMethodError: undefined method `normalize_params' for Rack::Utils:Module
   • 1 is ActionView::Template::Error: nil is not a valid asset source

   To fix: the kaminari paginator causing an ArgumentError Generating an URL from non sanitized request parameters is insecure! - use the master branch from github:

   gem 'kaminari', :git => "git://github.com/amatsuda/kaminari.git", :branch => 'master'
   

5. Deployment errors to AWS eb:

   There was a ArgumentError while loading rspec-support.gemspec:

   Temporary work-around : we run tests locally then comment-out rspec gems in gemfile before committing.

6. Errors in production:

   a) On refreshing the browser with existing session - got a session crash with a marshal error. This is similar to https://github.com/rails/rails/issues/18164:

   To fix: change the secret key base to invalidate all sessions.

   b) Gmail started categorizing emails as spam.

   To fix: duplicate the environment ( to get a new IP address ), swap URLs and delete the old environment.