Yesterday, my terraform modules worked, Today, none of my terraform modules work. Yesterday I also ran brew upgrade to update node, (so I could install commitizen, with a view to using sematic-release for versioning of my terraform modules. But that’s another story and probably another blog post when I’ve figured it out), could these things be related? Let’s find out.
Yes, they are related. ‘brew upgrade’ upgraded terraform from version 0.13.6 to 0.14.9 and broke everything. Lessons learned: use ‘brew pin’ to prevent things being upgraded. Use more stringent ‘required_versions’ for terraform within terraform modules.
Today I returned to my terraform studies. To my surprise terraform plan did not look pretty at all. The last git commit message I wrote said “everything works (yay!)” - so why didn’t it?
I retraced my steps to the day before, where I’d run brew upgrade, among other things, so I checked my terraform version. Again, to my surprise, I was running version 0.14.9. I’m sure I was on 0.13.something before. So, how to downgrade and, more importantly, how to make sure this didn’t happen again?
I found some useful info on apple.stackexchange.com about downgrading node via brew, so I just applied the same logic to terraform.
brew search terraform reveals the different versions available.
brew unlink terraform removes the symlinks brew creates in /usr/local
brew install terraform@0.13 installs the required version
brew link terraform@0.13 adds the symlinks for /usr/local
And now for the really important part:
brew pin terraform will prevent terraform from being upgraded next time I run brew upgrade.
Running terraform version displays Terraform v0.13.6 and terraform plan looks good once more.