Question

My production app is running on ruby 1.9.2 and rail 3.0.3.

What is the safest method to upgrade rails to 3.0.10, and is upgrading to rails 3.0.10 completely safe, or do I run the risk of some gem dependencies breaking something?

Answer 1

I had good success with the following approach:

1. Ensure that all your files that are relevant for development and production are in source control (preferably Git).
2. Ensure that your current 3.0.3 status is clean, everything is commited.
3. Make a branch on that.
4. Upgrade your Gemfile to ensure that the Rails version is upgrade to 3.0.10.
5. Do the normal bundle install tasks.
6. Do your tests as usual (you do have tests, no :-)).
7. Look for warnings and errors in the log.
8. If everything works fine, commit your changes, and switch back to your master.
9. Merge the changes and do then a normal delivery (not part of my answer).

Depending on the data you have in production, there may be extra steps necessary, but normally, you don’t change any functionality, you just upgrade the Rails version, so normally no migration change is necessary.

PS: The real job then is to upgrade to Rails 3.1.x …