Last week I upgraded the Lugo Labs website from Rails 4.2 to Rails 5.0.0.beta1. The process was easy overall, with some little tweaks. They involved the gems that I had installed in the app, and might not necessarily be the same as yours. Generally I found that the gem maintainers are doing a great job at updating their code bases to support the latest version of Rails, and I would like to thank them for that.
Ruby
Rails 5 asked me to install a Ruby version 2.2.1 or higher, so I did that with rbenv:
rbenv install 2.2.3
Rails
Then I tackled the Gemfile, starting with Rails:
# Gemfile
gem 'rails', '~> 5.0.0.beta1'
and run:
bundle update
Kaminari
The Kaminari gem was complaining about some other gem versions, but thanks to their maintainers, I could link to the github version, which fixed the issues:
# Gemfile
gem 'kaminari', git: 'git://github.com/amatsuda/kaminari.git'
Exception notifications
The the exception_notification wasn't happy, but its maintainer, Sebastian Martinez had already created a Rails 5 branch, so I updated the Gemfile again:
# Gemfile
gem 'exception_notification', github: 'smartinez87/exception_notification', branch: 'rails5'
Puma
One of the novelties in Rails 5 is ActionCable which uses Puma for concurrency, so I added that to my Gemfile too:
# Gemfile
gem 'puma'
I don't use ActionCable (yet?), but it's good to apply all the changes. Now when I run bundle update all works fine. Yey!
Happy days
Testing the website, all seems to function well, so happy days! I deployed the site to production, which also behaved well.
Check the DHH's original post for the new release.