Github: Upgrading from Rails 3.2 to 5.2. Took a year and a half

github-rails-upgrading.md

Github: Upgrading from Rails 3.2 to 5.2.

Took a year and a half

Introduction

2018 September

clean up technical debt

improve codebase

How did we do it?

large and trafficked application

Require

• careful planning
• good organization
• ⏳ patience

When?

• 1st. at free time
• then. ⭐ priority

dual boot

• Gemfile.lock
• Gemfile_next.lock

CI job

Engineers to get used to writing code that worked in multiple versions of Rails

testing environment

• click test
  • 🚧 fixing regressions

deploy to % of production servers

• collect data about
  • exceptions
  • performance

fix bugs

• error rate low enough

Lessons Learned

👵🏻Codebase is 10 years old

Upgrade early and upgrade often

Add a build to run against the master branch

• catch bugs

Save your application code for what truly makes your company special

Avoid using private APIs

⚠️ Ensure that the line where your applications ends and your framework begins is clear

Do incremental updates

Expect things to break

• due to large size of the application
• issues with CI, local development, slow queries

Was it worth it?

Rails upgrades

• are
  • a lot of hard work
  • can be time-consuming
• but they also
  • 💎 open up a ton possibilities