chore(wasm): add wasm32-wasip2 example

Signed-off-by: Brooks Townsend <[email protected]> example cleanup extra blocking feature Signed-off-by: Brooks Townsend <[email protected]> use body example Signed-off-by: Brooks Townsend <[email protected]>
seanmonstar · Oct 22, 2024 · 7edd47e · 7edd47e
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diff --git a/examples/wasm_component/.cargo/config.toml b/examples/wasm_component/.cargo/config.toml
@@ -0,0 +1,2 @@
+[build]
+target = "wasm32-wasip2"
diff --git a/examples/wasm_component/Cargo.toml b/examples/wasm_component/Cargo.toml
@@ -0,0 +1,25 @@
+[package]
+name = "http-reqwest"
+edition = "2021"
+version = "0.1.0"
+
+[workspace]
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+futures = "0.3.30"
+reqwest = { version = "0.12.5", path = "../../", features = ["stream"] }
+wasi = "=0.13.3" # For compatibility, pin to [email protected] bindings
+
+# https://github.com/servo/rust-url/pull/983
+[patch.crates-io]
+url = { git = "https://github.com/servo/rust-url", rev = "fc447cce1d2c06ef0bec3dbadce56b83e46ca1ff"}
+form_urlencoded = { git = "https://github.com/servo/rust-url", rev = "fc447cce1d2c06ef0bec3dbadce56b83e46ca1ff"}
+
+[profile.release]
+# Optimize for small code size
+lto = true
+opt-level = "s"
+strip = true
diff --git a/examples/wasm_component/README.md b/examples/wasm_component/README.md
@@ -0,0 +1,34 @@
+# HTTP Reqwest
+
+This is a simple Rust Wasm example that sends an outgoing http request using the `reqwest` library to [https://hyper.rs](https://hyper.rs).
+
+## Prerequisites
+
+- `cargo` 1.82+
+- `rustup target add wasm32-wasip2`
+- [wasmtime 23.0.0+](https://github.com/bytecodealliance/wasmtime)
+
+## Building
+
+```bash
+# Build Wasm component
+cargo build --target wasm32-wasip2
+```
+
+## Running with wasmtime
+
+```bash
+wasmtime serve -Scommon ./target/wasm32-wasip2/debug/http_reqwest.wasm
+```
+
+Then send a request to `localhost:8080`
+
+```bash
+> curl localhost:8080
+
+<!doctype html>
+<html>
+<head>
+    <title>Example Domain</title>
+....
+```
diff --git a/examples/wasm_component/src/lib.rs b/examples/wasm_component/src/lib.rs
@@ -0,0 +1,34 @@
+use wasi::http::types::{
+    Fields, IncomingBody, IncomingRequest, OutgoingBody, OutgoingResponse, ResponseOutparam,
+};
+
+#[allow(unused)]
+struct ReqwestComponent;
+
+impl wasi::exports::http::incoming_handler::Guest for ReqwestComponent {
+    fn handle(_request: IncomingRequest, response_out: ResponseOutparam) {
+        let response = OutgoingResponse::new(Fields::new());
+        response.set_status_code(200).unwrap();
+        let response_body = response
+            .body()
+            .expect("should be able to get response body");
+        ResponseOutparam::set(response_out, Ok(response));
+
+        let mut response = reqwest::get("https://hyper.rs").expect("should get response bytes");
+        let (mut body_stream, incoming_body) = response
+            .bytes_stream()
+            .expect("should be able to get response body stream");
+        std::io::copy(
+            &mut body_stream,
+            &mut response_body
+                .write()
+                .expect("should be able to write to response body"),
+        )
+        .expect("should be able to stream input to output");
+        drop(body_stream);
+        IncomingBody::finish(incoming_body);
+        OutgoingBody::finish(response_body, None).expect("failed to finish response body");
+    }
+}
+
+wasi::http::proxy::export!(ReqwestComponent);