wasi-http: Add default-send-request feature flag to disable default send handler

Author: brian14708

.github/workflows/main.yml

@@ -394,6 +394,10 @@ jobs:
               -p wasmtime-c-api --no-default-features
               -p wasmtime-c-api --no-default-features --features wat
               -p wasmtime-c-api --no-default-features --features wasi
+
+          - name: wasmtime-wasi-http
+            checks: |
+              -p wasmtime-wasi-http --no-default-features
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4

crates/wasi-http/Cargo.toml

@@ -11,6 +11,10 @@ description = "Experimental HTTP library for WebAssembly in Wasmtime"
 [lints]
 workspace = true
 
+[features]
+default = ["default-send-request"]
+default-send-request = ["dep:tokio-rustls", "dep:rustls", "dep:webpki-roots"]
+
 [dependencies]
 anyhow = { workspace = true }
 async-trait = { workspace = true }
@@ -29,9 +33,9 @@ tracing = { workspace = true }
 wasmtime-wasi = { workspace = true }
 wasmtime-wasi-io = { workspace = true }
 wasmtime = { workspace = true, features = ['component-model'] }
-tokio-rustls = { workspace = true }
-rustls = { workspace = true }
-webpki-roots = { workspace = true }
+tokio-rustls = { workspace = true, optional = true }
+rustls = { workspace = true, optional = true }
+webpki-roots = { workspace = true, optional = true }
 
 [dev-dependencies]
 test-programs-artifacts = { workspace = true }

crates/wasi-http/src/error.rs

@@ -58,6 +58,7 @@ impl fmt::Display for HttpError {
 
 impl Error for HttpError {}
 
+#[cfg(feature = "default-send-request")]
 pub(crate) fn dns_error(rcode: String, info_code: u16) -> ErrorCode {
     ErrorCode::DnsError(crate::bindings::http::types::DnsErrorPayload {
         rcode: Some(rcode),

crates/wasi-http/src/types.rs

@@ -1,12 +1,9 @@
 //! Implements the base structure (i.e. [WasiHttpCtx]) that will provide the
 //! implementation of the wasi-http API.
 
-use crate::io::TokioIo;
 use crate::{
     bindings::http::types::{self, Method, Scheme},
     body::{HostIncomingBody, HyperIncomingBody, HyperOutgoingBody},
-    error::dns_error,
-    hyper_request_error,
 };
 use anyhow::bail;
 use bytes::Bytes;
@@ -15,12 +12,18 @@ use hyper::body::Body;
 use hyper::header::HeaderName;
 use std::any::Any;
 use std::time::Duration;
-use tokio::net::TcpStream;
-use tokio::time::timeout;
 use wasmtime::component::{Resource, ResourceTable};
 use wasmtime_wasi::p2::{IoImpl, IoView, Pollable};
 use wasmtime_wasi::runtime::AbortOnDropJoinHandle;
 
+#[cfg(feature = "default-send-request")]
+use {
+    crate::io::TokioIo,
+    crate::{error::dns_error, hyper_request_error},
+    tokio::net::TcpStream,
+    tokio::time::timeout,
+};
+
 /// Capture the state necessary for use in the wasi-http API implementation.
 #[derive(Debug)]
 pub struct WasiHttpCtx {
@@ -112,6 +115,7 @@ pub trait WasiHttpView: IoView {
     }
 
     /// Send an outgoing request.
+    #[cfg(feature = "default-send-request")]
     fn send_request(
         &mut self,
         request: hyper::Request<HyperOutgoingBody>,
@@ -120,6 +124,14 @@ pub trait WasiHttpView: IoView {
         Ok(default_send_request(request, config))
     }
 
+    /// Send an outgoing request.
+    #[cfg(not(feature = "default-send-request"))]
+    fn send_request(
+        &mut self,
+        request: hyper::Request<HyperOutgoingBody>,
+        config: OutgoingRequestConfig,
+    ) -> crate::HttpResult<HostFutureIncomingResponse>;
+
     /// Whether a given header should be considered forbidden and not allowed.
     fn is_forbidden_header(&mut self, name: &HeaderName) -> bool {
         DEFAULT_FORBIDDEN_HEADERS.contains(name)
@@ -317,6 +329,7 @@ pub struct OutgoingRequestConfig {
 ///
 /// This implementation is used by the `wasi:http/outgoing-handler` interface
 /// default implementation.
+#[cfg(feature = "default-send-request")]
 pub fn default_send_request(
     request: hyper::Request<HyperOutgoingBody>,
     config: OutgoingRequestConfig,
@@ -331,6 +344,7 @@ pub fn default_send_request(
 /// in a task.
 ///
 /// This is called from [default_send_request] to actually send the request.
+#[cfg(feature = "default-send-request")]
 pub async fn default_send_request_handler(
     mut request: hyper::Request<HyperOutgoingBody>,
     OutgoingRequestConfig {

crates/wasi-http/tests/all/p2.rs

@@ -67,7 +67,16 @@ impl WasiHttpView for Ctx {
         if let Some(send_request) = self.send_request.clone() {
             Ok(send_request(request, config))
         } else {
-            Ok(types::default_send_request(request, config))
+            #[cfg(feature = "default-send-request")]
+            {
+                Ok(types::default_send_request(request, config))
+            }
+            #[cfg(not(feature = "default-send-request"))]
+            {
+                unimplemented!(
+                    "send_request is not implemented; either enable the `default-send-request` feature or provide a custom implementation"
+                )
+            }
         }
     }