k8s-openapi VS openapi-generator

It's called sans-io in Python land, which is where I heard it first.

https://sans-io.readthedocs.io/

I did it for one of my projects back in 2018 https://github.com/Arnavion/k8s-openapi/commit/9a4fbb718b119...

Another option is to implement your API in a sans-io form. Since k8s-openapi was mentioned (albeit for a different reason), I'll point out that its API gave you a request value that you could send using whatever sync or async HTTP client you want to use. It also gave you a corresponding function to parse the response, that you would call with the response bytes however you got them from your client.

https://github.com/Arnavion/k8s-openapi/blob/v0.19.0/README....

(Past tense because I removed all the API features from k8s-openapi after that release, for unrelated reasons.)

Macro expansion is slow, but only noticeably in the specific situation of a) third-party proc macros, b) a debug build, and c) a few thousand invocations of said proc macros. This is because debug builds compile proc macros in debug mode too, so while the macro itself compiles quickly (because it's a debug build), it ends up running slowly (because it's a debug build).

I know this from observing this on a mostly auto-generated crate that had a couple of thousand types with `#[derive(serde::)]` on each. [1]

This doesn't affect most users, because first-party macros like `#[derive(Debug)]` etc are not slow because they're part of rustc and are thus optimized regardless of the profile, and even with third-party macros it is unlikely that they have thousands of invocations. Even if it is* a problem, users can opt in to compiling just the proc macros in release mode. [2]

[1]: https://github.com/Arnavion/k8s-openapi/issues/4

[2]: https://github.com/rust-lang/cargo/issues/5622

>OpenAPI Generator allows generation of API client libraries from OpenAPI Specs

It does, but the generated code can be very shitty for some combinations of spec and output language. I maintain Rust bindings for the Kubernetes API server's API, and I chose to write my own code generator instead. The README at https://github.com/Arnavion/k8s-openapi has more details.

k8s_openapi - https://github.com/Arnavion/k8s-openapi

For example: I have a routine that checks the value of (from k8s-openapi): Ingress -> IngressStatus -> LoadBalancerStatus -> Vec[0] -> String

As the maintainer of the Rust bindings that the library used in the article (kube) is backed by, I can confirm that Kubernetes' openapi spec requires a lot of Kubernetes-specific handling to generate a good client than generic openapi generators do not provide.

See https://github.com/Arnavion/k8s-openapi/blob/master/README.m... for a full description.

I also confirm that I keep it up-to-date with Kubernetes releases and have been doing so for the ~3 years that it's been around. Not just the minor ones every few months, but even the point ones; these days the latter usually only involves updating the test cases instead of code changes and they're done within a few hours of the upstream release.

Disclaimer: We're an early adopter of Stainless at Mux.

I've spent more of my time than I'd like to admit managing both OpenAPi spec files [1] and fighting with openapi-generator [2] than any sane person should have to. While it's great having the freedom to change the templates an thus generated SDKs you get with using that sort of approach, it's also super time consuming, and when you have a lot of SDKs (we have 6 generated SDKs), in my experience it needs someone devoted to managing the process, staying up with template changes etc.

Excited to see more SDK languages come to Stainless!

[1] https://www.mux.com/blog/an-adventure-in-openapi-v3-api-code...

[2] https://github.com/OpenAPITools/openapi-generator

As a result, the following specification can be used to generate clients in a number of different languages via OpenAPI Generator.

Of course you can compile the server from source if you have Go and the OpenAPI generator JAR (https://github.com/OpenAPITools/openapi-generator?tab=readme...)

Follow these steps : https://github.com/c100k/rebootx-on-prem/blob/master/.github...

And then :

(cd ./impl/http-server-go && GOARCH=amd64 GOOS=openbsd go build -o /app/rebootx-on-prem-http-server-go-openbsd-amd64 -v)

By adapting the arch if needed. Not tested, but it should work.

TL;DR: Start generating your HTTP clients and all the DTOs of the requests and responses automatically from your API, using openapi-generator instead of writing your own.

As an alternative, you can also use the official OpenAPI Generator, which is a more generic tool supporting a wide range of languages and frameworks.

I trialed generating SDKs using the OpenAPI Generator package, which was largely unsatisfactory.

If Swagger/OpenAPI is available, save yourself a lot of trouble and generate the client using OpenAPI Generator. If not, use a library like RestEase to make it significantly easier to create the client.

For a run of the mill REST API you should generate OpenAPI (Swagger) info for the API using a library like NSwag or Swashbuckle. You'd want to do this no matter what because it's documentation for the API, but the bonus is that you can use it with tools like OpenAPI Generator to create API client code and models in a variety of languages. You certainly can create an API client library manually, it would entail having a nuget package with a class library that contains the models and client code for calling the endpoints (which I'd create using a lib such as RestEase unless you just enjoy writing boilerplate code by hand). However 95% of the time it simply isn't worth creating your own lib when OpenAPI is available because once you've done it a time or two it takes less than 5 min to run the generator and create (or update) a lib.

Then you can use oapi-codegen or openapi-generator to generate the Go (or other language) SDK for it.