This replaces kube-master with kube_control_plane because of [1]:
The Kubernetes project is moving away from wording that is
considered offensive. A new working group WG Naming was created
to track this work, and the word "master" was declared as offensive.
A proposal was formalized for replacing the word "master" with
"control plane". This means it should be removed from source code,
documentation, and user-facing configuration from Kubernetes and
its sub-projects.
NOTE: The reason why this changes it to kube_control_plane not
kube-control-plane is for valid group names on ansible.
[1]: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/2067-rename-master-label-taint/README.md#motivation
upgrades.md explains how to do upgrade from v1.4.3 to v1.4.6 as an
example. The versions are a little old, and the doc readers would
have a concern the upgrade works fine or not.
This updates versions after verifying the way works fine by hands.
Since it is unsupported to skip upgrades, I've detailed the steps for upgrading a step at a time and removed some language that indicated it should work
Clarify that the `kube_version` environment variable is needed for the CLI "graceful upgrade". Also add and example to check that the upgrade was successful.
Based on #718 introduced by rsmitty.
Includes all roles and all options to support deployment of
new hosts in case they were added to inventory.
Main difference here is that master role is evaluated first
so that master components get upgraded first.
Fixes#694
