Stream: wit-bindgen

Topic: Couldn't import wasi-http component in my project

Dmitry Chub (Feb 16 2025 at 17:56):

I would like to use WASI-HTTP components in my project and generate function something like:

   fn handle(_request: IncomingRequest, response_out: ResponseOutparam) {
        // some code
   }

in rust file I can import it without problem:

use wasi::http::types::{
   Fields, IncomingRequest, OutgoingBody, OutgoingResponse, ResponseOutparam,
};

but when I would like to declare components in WIT file

package component-model:example;

use wasi:http/types@1.0.0

and using wit_bindgen generate code for kotlin:

wit_bindgen::generate!({
    path: "wit",
    exports: {
      "component-model:example/test": Test,
    },
});

I got this error:

error: failed to find package `wasi:http@0.2.3` in `deps` directory
            --> C:\rust-component\wit\example.wit:5:5
             |
           5 | use wasi:http/types@0.2.3;
             |     ^--------

I have already specified wasi version in Cargo.toml file

wasi = "0.14.1"

Looks like I have missed something or make mistake...

Pat Hickey (Feb 17 2025 at 06:07):

When you use wit-bindgen, its expecting to find wit files at the path: you specify in the macro, which is relative to the crate root. You probably don't actually want to do that, though. I fyou are just trying to export your wasi-http incoming handler from your function, you can do that with the wasi crate (no need for wit-bindgen) with https://docs.rs/wasi/latest/wasi/http/proxy/macro.export.html

Last updated: Feb 28 2025 at 02:27 UTC