Microshift nodes are missing some useful OpenShift node labels.

OpenShift implements node-selector labels to expose node OS information.

Some existing OpenShift tests and scripts use the node.openshift.io/os_id label to select between rhcos and rhel nodes.

It would be nice to be able to differentiate between rhel and rhcos nodes, or perhaps also microshift specific nodes.

OpenShift implements node labels in the kubelet command line in the templated machine config

EnvironmentFile=/etc/os-release
ExecStart=/usr/local/bin/kubenswrapper \
      /usr/bin/kubelet \
 --node-labels=node-role.kubernetes.io/master,node.openshift.io/os_id=${ID}

https://github.com/openshift/machine-config-operator/blob/master/templates/master/01-master-kubelet/_base/units/kubelet.service.yaml#L32

bash-4.4# cat /etc/os-release
NAME="Red Hat Enterprise Linux"
VERSION="8.6 (Ootpa)"
ID="rhel"