MicroTime serialises incorrectly

[LiamClarkeNZ]

As per my investigation recorded on this ticket here, io.fabric8.kubernetes.api.model.MicroTime serialises incorrectly.

When creating an Event, fabric8 serialises MicroTime as an object but the k8s server is expecting it as a string (in RFC-3339 format).

Looking into how the generated models are derived (Go struct public members reflected -> JSON schema -> jsonschema2pojo) I can see how this arose, MicroTime is indeed a struct with a field called Time, but it serialises to/from a string on the server.

I have a workaround, which is to subclass MicroTime (thank you so much for not making it final!) and override the JSON serialisation logic (I won't embed it inline for the purposes of conciseness)

https://gist.github.com/LiamClarkeNZ/65f0888d2bcb1dfe9807c873ff4f18cb

Who would fix this?

I'd be very happy to submit a PR once I understand what a good solution looks like from the maintainers' point of view.

The question is, what does that good solution look like?

The current Go struct -> JSON schema -> pojo seems to work ideally for 99.9% of cases. v1.MicroTime looks to be a rather special case. So I can see several options.

1. Modify the Go struct -> JSON schema step to take advantage of Go types exposing OpenAPISchemaType() and OpenAPISchemaFormat() to ensure that the Go type and the serialised type align.
2. Special case MicroTime - exclude it from generation, and rely on a hand-crafted copy.

Special casing always feels like a bad choice, but if this struct/serialisation representation mismatch only affects one type, it might be the easiest approach. It also offers the advantage that a hand-crafted model could make it easier in converting a Java date-time representation to a K8s one.

E.g., in my Gist, the workaround requires a ZonedDateTime (as one is needed to serialise to a format with TZ) and formats the string to ensure that K8s can deserialise it, removing some burden on end users.

TL;DR - MicroTime serialisation is currently not working, I'm very happy to submit a PR to fix it, I just want to find out what maintainers think is the best way to do so :)

[rohanKanojia]

@LiamClarkeNZ : Thanks a lot for your detailed bug report!

You're right we can easily fix this issue by providing a hand-crafted copy of MicroTime with custom Serializers/Deserializers. When I was reading your bug report this was the solution I wanted to go forward with. We've done this in past too for classes like IntOrString

Modify the Go struct -> JSON schema step to take advantage of Go types exposing OpenAPISchemaType() and OpenAPISchemaFormat() to ensure that the Go type and the serialized type align.

This approach sounds interesting. If we can invoke this method via reflection to get openApiSchemaType that would be really nice. However, I think at this point I wonder if it can introduce some breaking changes. Do you think we should create a separate issue for discussing using OpenAPISchemaType() in generator scipt?

[LiamClarkeNZ]

@rohanKanojia Yep, I think using OpenAPISchemaType() is a far more wide-ranging change in type generation, so needs more investigation. Thanks for the PR!