enable connection pooling and reuse for outbound wasi-http

Cargo.toml

@@ -164,6 +164,7 @@ tokio = "1"
 tokio-rustls = { version = "0.26", default-features = false, features = ["logging", "tls12"] }
 toml = "0.8"
 toml_edit = "0.22"
+tower-service = "0.3.3"
 tracing = { version = "0.1.41", features = ["log"] }
 url = "2"
 walkdir = "2"
@@ -186,4 +187,4 @@ blocks_in_conditions = "allow"
 
 [[bin]]
 name = "spin"
-path = "src/bin/spin.rs"
+path = "src/bin/spin.rs"

crates/factor-outbound-http/Cargo.toml

@@ -19,6 +19,7 @@ spin-telemetry = { path = "../telemetry" }
 spin-world = { path = "../world" }
 tokio = { workspace = true, features = ["macros", "rt", "net"] }
 tokio-rustls = { workspace = true }
+tower-service = { workspace = true }
 tracing = { workspace = true }
 wasmtime = { workspace = true }
 wasmtime-wasi = { workspace = true }

crates/factor-outbound-http/src/lib.rs

@@ -67,6 +67,7 @@ impl Factor for OutboundHttpFactor {
             self_request_origin: None,
             request_interceptor: None,
             spin_http_client: None,
+            wasi_http_clients: None,
         })
     }
 }
@@ -80,6 +81,8 @@ pub struct InstanceState {
     request_interceptor: Option<Arc<dyn OutboundHttpInterceptor>>,
     // Connection-pooling client for 'fermyon:spin/http' interface
     spin_http_client: Option<reqwest::Client>,
+    // Connection pooling client for `wasi:http/outgoing-handler` interface
+    wasi_http_clients: Option<wasi::HttpClients>,
 }
 
 impl InstanceState {