Bosh Release Property Validation RFC

[jpalermo]

Markdown View of the RFC

[beyhan]

During the TOC meeting on 28.01.2025 we decided to start the FCP with the goal to accept this RFC.

[cweibel]

I like the idea of the validation on the director side. It can be frustrating to generate all your certificates in credhub only to find out after hours of debugging that the SAN configuration was wrong.

[teddyking]

Hi everyone 👋 I've just been made aware of this PR as we have been wanting to perform some fairly advanced validation logic in one of our BOSH releases. Overall I think this is great and will add a lot of value but there are a couple of specifics that I'm not sure would be covered with JSON scheme:

• Cross field validation - for example given a property named foos, which is an array of strings, and another property named requested-foo, which is a string, validate that the value of requested-foo is contained within the values of the foos array.
• Uniqueness in arrays of objects - you can check uniqueness for simple arrays ["foo","foo'], but not if for arrays of objects: [{"name":"foo"},{"name":"foo"}].

Maybe it is possible to do these (in which case please let me know!) but if not I thought I'd mention them in case anyone else had similar requirements.

[jpalermo]

Hi @teddyking ,
I've not actually used json schema much, but looking around, maybe $data could be used to accomplish the first thing.

And it looks like uniqueItems does the second bit too. Seems like the ability to do uniqueness on non-primitive types must have been added in a recent draft of the schema because some older info says it isn't possible, but I tried it out and it seemed to work with objects or nested arrays just fine.

We are open to adding validations that would be useful to multiple releases. But we probably want to keep the number of custom validations at least somewhat limited. So for more specific things, the recommendation would be to put them in the application logic or a pre-start script of some kind.