RUST-1973 Example client usage targeting WasmEdge (#1137)

Author: abr-egn

etc/wasmedge/.cargo/config.toml

@@ -0,0 +1,3 @@
+[build]
+target = "wasm32-wasi"
+rustflags = ["--cfg", "wasmedge", "--cfg", "tokio_unstable"]

etc/wasmedge/.gitignore

@@ -0,0 +1,2 @@
+target/
+Cargo.lock

etc/wasmedge/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "wasmedge_mongodb"
+version = "0.1.0"
+edition = "2021"
+
+[patch.crates-io]
+tokio = { git = "https://github.com/second-state/wasi_tokio.git", branch = "v1.36.x" }
+socket2 = { git = "https://github.com/second-state/socket2.git", branch = "v0.5.x" }
+
+[dependencies]
+mongodb = { path = "../../", default_features = false, features = ["compat-3-0-0", "rustls-tls"] }
+tokio = { version = "1", features = ["io-util", "fs", "net", "time", "rt", "macros"] }

etc/wasmedge/README.md

@@ -0,0 +1,9 @@
+Please note: using the MongoDB Rust driver on WasmEdge is unsupported!
+
+This example program requires:
+* WasmEdge (https://wasmedge.org/docs/start/install/)
+* The Rust wasm toolchain (`rustup target add wasm32-wasi`)
+
+To compile: `cargo build --target wasm32-wasi --release`
+
+To run: `wasmedge target/wasm32-wasi/release/wasmedge_mongodb.wasm`

etc/wasmedge/src/main.rs

@@ -0,0 +1,7 @@
+#[tokio::main(flavor = "current_thread")]
+async fn main() {
+    let client = mongodb::Client::with_uri_str("mongodb://127.0.0.1:27017")
+        .await
+        .unwrap();
+    println!("{:?}", client.list_database_names().await);
+}

src/client/auth/oidc.rs

@@ -714,6 +714,7 @@ fn validate_address_with_allowed_hosts(
     mechanism_properties: Option<&Document>,
     address: &ServerAddress,
 ) -> Result<()> {
+    #[allow(irrefutable_let_patterns)]
     let hostname = if let ServerAddress::Tcp { host, .. } = address {
         host.as_str()
     } else {

src/runtime/stream.rs

@@ -20,6 +20,7 @@ use super::{
 };
 
 pub(crate) const DEFAULT_CONNECT_TIMEOUT: Duration = Duration::from_secs(10);
+#[cfg(not(target_os = "wasi"))]
 const KEEPALIVE_TIME: Duration = Duration::from_secs(120);
 
 /// An async stream possibly using TLS.
@@ -67,8 +68,11 @@ async fn tcp_try_connect(address: &SocketAddr) -> Result<TcpStream> {
     stream.set_nodelay(true)?;
 
     let socket = socket2::Socket::from(stream.into_std()?);
-    let conf = socket2::TcpKeepalive::new().with_time(KEEPALIVE_TIME);
-    socket.set_tcp_keepalive(&conf)?;
+    #[cfg(not(target_os = "wasi"))]
+    {
+        let conf = socket2::TcpKeepalive::new().with_time(KEEPALIVE_TIME);
+        socket.set_tcp_keepalive(&conf)?;
+    }
     let std_stream = std::net::TcpStream::from(socket);
     Ok(TcpStream::from_std(std_stream)?)
 }