See kubernetes-announce@ and CHANGELOG-1.12.md for details.
SHA256 for kubernetes.tar.gz: 7163d18b9c1bd98ce804b17469ed67b399deb7b574dd12a86609fc647c5c773b
Additional binary downloads are linked in the CHANGELOG-1.12.md.
https://github.com/kubernetes/kubernetes/releases/tag/v1.12.0-beta.2