The Kubernetes docs state that four "commonly used name constraints" are RFC1123 subdomain names, RFC1123 label names, RFC1035 label names, and (posix?) path segments. These constraints differ e.g. in maximum length, whether any uppercase is permissible, what symbols are permissible, and whether the first character must be a letter or can also be a numeral, etc. Which constraints apply to which Kubernetes resource kinds? As a particular example, can the name of an ingress begin with a numeral?
The motivation for this question is that the AWS Load Balancer is clunky to configure with numerical explicit rule ordering (because alb.ingress.kubernetes.io/group.order must be maintained to be unique among all ingresses in the group, and reassigning precedence values requires a seperate removal stage that seems incongruous with "infrastructure as code"), but the "implicit" default ordering is supposed to be alphabetic by ingress name. This suggests (for routing multiple ingresses from the same host domain) a simpler solution of just prepending a number to the name of the ingress for the more-specific path.
