Add support for Android Native builds

[lukewarlow]

Currently Kotlinx-rpc doesn't seem to support Android native, I have a use case where I would want to use the core of the library (codegen, client/server declaration and the krpc protocol) inside a kotlin/native binary running on Android.

For my use case I don't need the ktor stuff as I'll be writing a custom a transport.

[lukewarlow]

Fwiw my use case is a multi-process application where the main UI process is kotlin/jvm, but the other processes will be kotlin/native. Android will be the only place to use JVM anywhere so the norm would be kotlin/native for every platform.

I'm looking to use kotlinx-rpc for the IPC system with a custom KRPC transport that uses a variety of underlying mechanisms (e.g. XPC on macOS/iOS). So it would be good for even just the core codegen and kprc protocol to support androidNative.

[Mr3zee]

@lukewarlow thanks for the use case! I'll see how hard it would be to support it quickly

[lukewarlow]

If there's anything I can do to help with this effort let me know.

[Mr3zee]

It's just we don't have time to do this (also setting up CI). It's on the todo list

[ANURAGX]

I see the linux support is added, if linux is in working condition, then why not androidNative.
My usecase is, I have an SDK written in C++ for different platforms, I m migrating the SDK to Kotlin Multiplatform. My target platforms are android, androidNative, jvm, ios, mac, linux, windows.

[Mr3zee]

@ANURAGX just to clarify: do you need androidNative for the kRPC or the newly added gRPC?

[ANURAGX]

grpc, my backend written in golang, supports rest api and rpc. and we want to make best use of grpc.

[Mr3zee]

Noted, we'll explore that, thanks!

[Rawa]

@Mr3zee I've been peaking into this repo for a while, and would like to add our use case. We use gRPC over UDS (Unix Domain Socket) to perform IPC. We share the daemon code (written in Rust) with our desktop platforms that also connect over gRPC.

Currently in the android app we make use of gRPC-java and gRPC-kotlin, however their implementations are not so good 🙈, so we have been looking into other options and I think kotlinx-rpc could be a good fit. We've also looked into using Wire instead however, we've yet not gotten streaming calls to work with it when using UDS.

The app in question is Mullvad VPN

[Mr3zee]

Oh, I know the app, it's a cool VPN!

Back to the topic 😅 Is android native support the only thing you'll need in order for your app to work? Or are there any other blockers?

[Rawa]

Back to the topic 😅 Is android native support the only thing you'll need in order for your app to work? Or are there any other blockers?

Sorry I think I misunderstood this task, no for us androidNative is not a blocker. Just android support is enough, and as far I understand this is supported now with gRPC. So maybe we should take a new stab on our side to see if we can get this to work with UDS.

[Mr3zee]

Yes, Android is supported now (except possible bugs 👀)

[ANURAGX]

any updates on AndroidNative, just now I finished integrating kotlin's grpc with my backed system, i struggled a lot mainly because of lack of proper document. I was able to move from rest to grpc for almost all platform (java, android, ios, others not tested -> mac, linux) , for now only windwos and AndroidNative target is left.

I must say even though this is in alpha, it works like a charm, no problem in code-gen , the generated code was able to connect to our 5 year old written grpc systems.

Any future for the release will also me to plan better.

[Mr3zee]

@ANURAGX happy to hear you didn't have major problems!
For the androidNative part, I didn't explore it yet (struggling with some plain native bugs for now), but it's on my list.

[ANURAGX]

@Mr3zee Thank you so much for showing me hope.