Uppercase node hostnames not supported by cluster upgrade scripts to 3.7.

Issue

• Our internal host names contain uppercase, characters, example:

Master1.example.com

• Upgrading Openshift 3.6 to 3.7 using upgrade playbook fails with following summary:

PLAY RECAP ******************************************************************
Master1.example.com : ok=270  changed=51   unreachable=0    failed=1   
[...]
Failure summary:

  1. Hosts:    Master1.example.com
     Play:     Drain and upgrade master nodes
     Task:     Wait for node to be ready
     Message:  Failed without returning a message.

• Upgrading to OCP 3.7 fails and all nodes are in NotReady state
• Therefore, we are affected by the following: Bug 1396350

Example log output:

# journalctl -u atomic-openshift-node -l --no-pager:
[...]
Dec 19 14:31:59 Master1.example.com atomic-openshift-node[24516]: I1219 14:31:59.403106   24516 kubelet_node_status.go:82] Attempting to register node master1.example.com
Dec 19 14:31:59 Master1.example.com atomic-openshift-node[24516]: E1219 14:31:59.406546   24516 kubelet_node_status.go:106] Unable to register node "master1.example.com" with API server: nodes "master1.example.com" is forbidden: node Master1.example.com cannot modify node master1.example.com