Minion ID should match Kubernetes node name constraints

[TeddyAndrieux]

Component:

salt, kubernetes

What happened:

If I set the Salt Minion ID manually (or using hostname) to something that does not match K8s node name constraints (e.g: with some underscore in it), it fail as we use this minion ID to "override" kubelet hostname which cannot contain any underscore

Error is not clear as we just have static pods that cannot be scheduled.

invalid pod: [metadata.name: Invalid value: "salt-master-my_node": a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*') spec.nodeName: Invalid value: "my_node": a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')]

What was expected:

Proper error handling

Steps to reproduce

Just set Salt Minion ID or hostname to something with underscore and start bootstrap process

Resolution proposal (optional):

At the beginning of the bootstrap check that the minion ID match constraints, fail with a clear message if it's not the case