Inspiration: OpenAPI schema

[Tal Liron <tliron@redhat.com>]

As some of you may know, Kubernetes, like TOSCA, supports custom data validation. You cannot create custom data types, but there is a fairly rich grammar for specifying constraints. This grammar is based on the schema specification for OpenAPI 3.0.

Generally speaking, TOSCA is more powerful. However, where OpenAPI is better is in allowing constraints beyond individual parameters. For example, you can express something like "one and exactly one of these is required".

IÂ haven't delved into it very deeply, but thought it might interest us as a source of inspiration for improving TOSCA.