Design Spec Review: Schema-Backed Validate() Methods on meshery/schemas Entity Types

[Lee Calcote]

Hi Everyone,

Regarding entity definition validation (e.g., verifying a relationship defined in a Meshery model), any Meshery component that processes untrusted or user-authored definition files must validate against schema-defined constraints. Today, every Meshery component performs this validation independently.

Open pull requests for two new CLI subcommands, `mesheryctl relationship validate` and `mesheryctl model validate` subcommands pull requests have been placed on-hold while this  proposal is considered. We can't sustain hand-rolling validation - much less doing so in slightly different ways in each component. I suspect that the revised approach involved stripping out the recently added validation capabilities in MeshKit, too.

I propose that a single, canonical schema-backed validation engine should live in a dependency-leaf package owned by meshery/schemas, and that MeshKit should reuse this engine. Ideally, meshery/schemas should not import MeshKit, which would prevent a cyclic dependency. The reality is that meshery/schemas imports MeshKit today.

The good news is that full MeshKit displacement is not necessary; the hard rule is acyclic package boundaries in the validation path. 

Proposal and Action Requested

This email is a Request for Comment (RFC) on proposed changes to how Meshery handles schema-based validation of its entities (e.g. Models, Components, Relationships, Designs, and so on), which emcompasses Meshery Schemas, Server, MeshKit, CLI, and Adapters. Please see the following GitHub issue and accompanying design specification. Comment at-will in reply to this email and/or on the open issue.

• Issue - https://github.com/meshery/schemas/issues/624
• Design specification - https://github.com/meshery/schemas/blob/master/specs/validation-package.md

This RFC will be open through EOD on Monday, March 16th. Everyone is invited to consider this proposal, comment, ask questions, and help strengthen or refute this proposal at-will.

Regards,

Lee