Perhaps off-topic but how have people upgraded TF codebases to new versions? Just last year we had a big effort to upgrade a huge code-base from 0.11 to 0.12. I feel like it should be a lot smoother than a full-team full-sprint effort.
Terraform 0.11 to 0.12 is by far the most difficult of the versions to upgrade between. I am really sorry about that. The other upgrades should be relatively minor as long as you read and follow the upgrade guides and upgrade one minor version at a time (0.11 => .12 => .13 etc.). There are rough edges for very specific cases but most of our customers were able to upgrade from 0.12 to subsequent versions same day without issue.
Breaking changes and difficult upgrades is not something we want to do with Terraform (0.12 being a big exception as that was a very core "reset" so to speak). The reason there have been these changes in these recent releases is that we've been ensuring Terraform is in a place for 1.0 that we don't have to have difficult upgrades.
You can see this path happening in each release:
- Terraform 0.15: state file format stability
- Terraform 0.14: provider dependency lock file
- Terraform 0.13: required provider block (for more deterministic providers)
- Terraform 0.12: stable JSON formats for plans/config parsing/etc. (particularly useful for interop with things like Terraform Cloud and 3rd party tooling)
This was all done to lead up to a stable 1.0 release.
As noted in the blog post, 0.15 is effectively a 1.0 pre-release so if everything goes well, we've MADE IT. For 1.0, we'll be outlining a number of very detailed compatibility promises which will make upgrades much easier going forward. :)