Feature Request: Custom linting rules for edge.json

[sbonami]

Similar to #188, I'm looking to help our team build better software by reinforcing best practices and standards. One of the ways we can do that is to introduce opinionated lint rules that gently guide us towards a standard style. I understand the focus of this library to be configuration and validation, so linting seems to be a fair tangent on that notion. Enabling custom lint rules would make the developer experience much smoother and drive stronger adoption within a customer's organization.

If nothing else, perhaps a little partnership between this and https://github.com/apigee/apigeelint with some helpful externalPlugins that lint the edge.json configuration? Like #188, it would be great to enable developers to shift left in their development process and identify issues sooner. The other request is for hard validation rules, where this is based more on softer preferences.

Some rules that come to mind:

• names should follow a specific pattern ("ExampleKVM" or "EXT-GCP-Stackdriver")
• resourcefile filenames should be snake_case
• cache timeouts must be no more than 3600
• Developer emails must be @organization.com

I recognize this request is a much farther stretch than just #188's validation, as it could conceivably encompass rules for almost every attribute. I think, however, that's where a little extension work with apigeelint could go a long way.

Unlike #188, I am unable to contribute this functionality the library at this time. Perhaps once we're up and running with the former, I could circle back. Either way, I wanted to again raise with the users and maintainers to gather any insights.