Docker and Kubernetes integrations compatibility matrix?
Every Kubernetes release has an External Dependencies section in the respective Changelog. E.g.:

CHANGELOG-1.14:


  The list of validated docker versions has changed. 1.11.1 and 1.12.1
  have been removed. The current list is 1.13.1, 17.03, 17.06, 17.09,
  18.06, 18.09.


CHANGELOG-1.13:


  The list of validated docker versions remain unchanged at 1.11.1,
  1.12.1, 1.13.1, 17.03, 17.06, 17.09, 18.06 since Kubernetes 1.12.


CHANGELOG-1.12:


  The list of validated docker versions was updated to 1.11.1, 1.12.1,
  1.13.1, 17.03, 17.06, 17.09, 18.06.


and so on...