feat: add the HTTP bindings to perform HTTP requests from workers (#168)

* feat: add the HTTP bindings to perform HTTP requests from workers

* fix: exclude wit-bindgen-backport packages from cargo deny

* fix: remove unnecesary channel when calling reqwest

* fix: remove unnecesary intermediate variable

* improve: implement From<reqwest::Error> to build the final error for the binding

Cargo.toml

@@ -68,8 +68,10 @@ exclude = [
 actix-web = "4"
 anyhow = "1.0.66"
 lazy_static = "1.4.0"
+reqwest = "0.11"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.85"
+tokio = "1.28"
 toml = "0.7.0"
 wws-config = { path = "./crates/config" }
 wws-runtimes = { path = "./crates/runtimes" }

crates/project/Cargo.toml

@@ -8,13 +8,14 @@ repository = { workspace = true }
 
 [dependencies]
 anyhow = { workspace = true }
+reqwest = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
+tokio = { workspace = true }
 toml = { workspace = true }
 wws-store = { workspace = true }
 url = "2.3.1"
 sha256 = "1.1.1"
-reqwest = "0.11"
 git2 = "0.17.2"
 # Not all platforms require OpenSSL
 openssl = { workspace = true, optional = true }

crates/worker/Cargo.toml

@@ -12,14 +12,19 @@ doctest = false
 [dependencies]
 actix-web = { workspace = true }
 anyhow = { workspace = true }
+reqwest = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
+tokio = { workspace = true }
 toml = { workspace = true }
 wasmtime = { workspace = true }
 wasmtime-wasi = { workspace = true }
 wasi-common = { workspace = true }
 wws-config = { workspace = true }
 wws-data-kv = { workspace = true }
 wws-runtimes = { workspace = true }
+# We didn't integrate components yet. For an initial binding implementation,
+# we will use the wit-bindgen-wasmtime crate maintained by the Fermyon team.
+wit-bindgen-wasmtime = { git = "https://github.com/fermyon/wit-bindgen-backport", rev = "b89d5079ba5b07b319631a1b191d2139f126c976" }
 base64 = "0.21.0"
 sha256 = "1.1.1"

crates/worker/src/bindings/http.rs

@@ -0,0 +1,119 @@
+// Copyright 2023 VMware, Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+use reqwest::Method;
+use tokio::runtime::Builder;
+
+// Implement the HTTP bindings for the workers.
+wit_bindgen_wasmtime::export!({paths: ["../../wit/core/http.wit"]});
+use http::{Http, HttpError, HttpMethod, HttpRequest, HttpRequestError, HttpResponse};
+
+pub use http::add_to_linker;
+
+pub struct HttpBindings {}
+
+/// Map the reqwest error to a known http-error
+/// HttpError comes from the HTTP bindings
+impl From<reqwest::Error> for HttpError {
+    fn from(value: reqwest::Error) -> Self {
+        if value.is_timeout() {
+            HttpError::Timeout
+        } else if value.is_redirect() {
+            HttpError::RedirectLoop
+        } else if value.is_request() {
+            HttpError::InvalidRequest
+        } else if value.is_body() {
+            HttpError::InvalidRequestBody
+        } else if value.is_decode() {
+            HttpError::InvalidResponseBody
+        } else {
+            HttpError::InternalError
+        }
+    }
+}
+
+impl Http for HttpBindings {
+    fn send_http_request(
+        &mut self,
+        req: HttpRequest<'_>,
+    ) -> Result<HttpResponse, HttpRequestError> {
+        // Create local variables from the request
+        let mut headers = Vec::new();
+        let uri = req.uri.to_string();
+        let body = req.body.unwrap_or(&[]).to_vec();
+
+        for (key, value) in req.headers {
+            headers.push((key.to_string(), value.to_string()));
+        }
+
+        // Run the request in an async thread
+        let thread_result = std::thread::spawn(move || {
+            Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .unwrap()
+                .block_on(async {
+                    let client = reqwest::Client::new();
+
+                    let method = match req.method {
+                        HttpMethod::Get => Method::GET,
+                        HttpMethod::Post => Method::POST,
+                        HttpMethod::Put => Method::PUT,
+                        HttpMethod::Patch => Method::PATCH,
+                        HttpMethod::Delete => Method::DELETE,
+                        HttpMethod::Options => Method::OPTIONS,
+                        HttpMethod::Head => Method::HEAD,
+                    };
+
+                    let mut builder = client.request(method, uri);
+
+                    for (key, value) in headers {
+                        builder = builder.header(key, value);
+                    }
+
+                    builder = builder.body(body);
+
+                    match builder.send().await {
+                        Ok(res) => {
+                            let mut headers = Vec::new();
+                            let status = res.status().as_u16();
+
+                            for (name, value) in res.headers().iter() {
+                                headers
+                                    .push((name.to_string(), value.to_str().unwrap().to_string()));
+                            }
+
+                            let body = res.bytes().await;
+
+                            Ok(HttpResponse {
+                                headers,
+                                status,
+                                body: Some(body.unwrap().to_vec()),
+                            })
+                        }
+                        Err(e) => {
+                            let message = e.to_string();
+
+                            // Manage the different possible errors from Reqwest
+                            Err(HttpRequestError {
+                                error: e.into(),
+                                message,
+                            })
+                        }
+                    }
+                })
+        })
+        .join();
+
+        match thread_result {
+            Ok(res) => match res {
+                Ok(res) => Ok(res),
+                Err(err) => Err(err),
+            },
+            Err(_) => Err(HttpRequestError {
+                error: HttpError::InternalError,
+                message: "There was an error processing the request on the host side.".to_string(),
+            }),
+        }
+    }
+}

crates/worker/src/bindings/mod.rs

@@ -0,0 +1,4 @@
+// Copyright 2023 VMware, Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+pub mod http;