Experimenting With .NET & WebAssembly - Running .NET Based Slight Application On WASM/WASI Node Pool in AKS

A year ago I wrote about running a .NET based Spin application on a WASI node pool in AKS. Since then the support for WebAssembly in AKS hasn't changed. We still have the same preview, supporting the same versions of two ContainerD shims: Spin and Slight (a.k.a. SpiderLightning). So why am I coming back to the subject? The broader context has evolved.

With WASI preview 2, the ecosystem is embracing the component model and standardized APIs. When I was experimenting with Spin, I leveraged WAGI (WebAssembly Gateway Interface) which allowed me to be ignorant about the Wasm runtime context. Now I want to change that, cross the barrier and dig into direct interoperability between .NET and Wasm.

Also, regarding the mentioned APIs, one of the emerging ones is wasi-cloud-core which aims to provide a generic way for WASI applications to interact with services. This proposal is not yet standardized but it has an experimental host implementation which happens to be Slight. By running a .NET based Slight application I want to get a taste of what that API might bring.

Last but not least, .NET 8 has brought a new way of building .NET based Wasm applications with a wasi-experimental workload. I want to build something with it and see where the .NET support for WASI is heading.

So, this "experiment" has multiple angles and brings together a bunch of different things. How am I going to start? In the usual way, by creating a project.

Creating a .NET 8 wasi-wasm Project

The wasi-experimental workload is optional, so we need to install it before we can create a project.

dotnet workload install wasi-experimental

It also doesn't bundle the