Terraform 0.12 broke compatability and this could result in data loss
if we deleted the etcd volumes. Document the procedure to fix the
tfstate, and require an env var to be passed to avoid accidental data
loss.
The ACM bugfix will fail API validation with k8s >=1.19 + `sslCertificate` + `class: Classic`.
The error message will contain this permalink, so I'd like to get eyes on this early.
If/when we handle migration without downtime, we can update these instructions to match.
As discussed during yesterday's office hours.
This should be cherry-picked back to 1.16.
We'll need to bump the minor version in the 1.17 and master branches.
Once we officially drop support we could make this a sliding window that uses the `kops.Version` variable.
I think we could have deprecation warnings for the 2 oldest versions still supported by the kops version, announcing that the n+2 Kops version will no longer support the specified k8s version.