The variable is defined in `kubernetes/preinstall` role and used in several roles. Since `kubernetes/preinstall` is not always included when `ansible-playbook` is run with tag selectors (see #5734 for reason), they will fail, or individual roles must copy the same fact definitions (as in #3846). Moving the definition to the always-included `kubespray-defaults` role will resolve the dependency problem.
* Add docker-ce 19.03 packages for Debian & Ubuntu
K8s has updated the recommended Docker version to 19.03. More
specifically it should be 19.03.4, but since we used 18.06.7 instead of
.2, I'm assuming the latest patch version should be used here as well.
* Add docker 19.03 for redhat
refs #5277
As the issue describes, when no external or local load-balanced is used,
kube-proxy won't be able to contact apiserver at 127.0.0.1. So the
config map should be left as is.