add missing file

web3-proxy/src/frontend.rs

@@ -0,0 +1,94 @@
+/// this should move into web3-proxy once the basics are working
+use axum::{
+    // error_handling::HandleError,
+    handler::Handler,
+    http::StatusCode,
+    response::IntoResponse,
+    routing::{get, post},
+    Extension,
+    Json,
+    Router,
+};
+use serde_json::value::RawValue;
+use std::net::SocketAddr;
+use std::sync::Arc;
+use tracing::warn;
+
+use crate::{
+    app::Web3ProxyApp,
+    jsonrpc::{JsonRpcErrorData, JsonRpcForwardedResponse, JsonRpcRequestEnum},
+};
+
+pub async fn run(port: u16, proxy_app: Arc<Web3ProxyApp>) -> anyhow::Result<()> {
+    // build our application with a route
+    let app = Router::new()
+        // `GET /` goes to `root`
+        .route("/", get(root))
+        // `POST /` goes to `proxy_web3_rpc`
+        .route("/", post(proxy_web3_rpc))
+        // `GET /status` goes to `status`
+        .route("/status", get(status))
+        .layer(Extension(proxy_app));
+
+    let app = app.fallback(handler_404.into_service());
+
+    // run our app with hyper
+    // `axum::Server` is a re-export of `hyper::Server`
+    let addr = SocketAddr::from(([0, 0, 0, 0], port));
+    tracing::debug!("listening on {}", addr);
+    axum::Server::bind(&addr)
+        .serve(app.into_make_service())
+        .await
+        .map_err(Into::into)
+}
+
+/// basic handler that responds with a page for configuration your
+/// TODO: check auth (from authp?) here?
+async fn root() -> impl IntoResponse {
+    "Hello, World!"
+}
+
+// TODO: i can't get https://docs.rs/axum/latest/axum/error_handling/index.html to work
+async fn proxy_web3_rpc(
+    payload: Json<JsonRpcRequestEnum>,
+    state: Extension<Arc<Web3ProxyApp>>,
+) -> impl IntoResponse {
+    match state.0.proxy_web3_rpc(payload.0).await {
+        Ok(response) => (StatusCode::OK, serde_json::to_string(&response).unwrap()),
+        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, format!("{}", e)),
+    }
+}
+
+/// Status page
+async fn status() -> impl IntoResponse {
+    (StatusCode::INTERNAL_SERVER_ERROR, "Hello, list_rpcs!")
+}
+
+async fn handler_404() -> impl IntoResponse {
+    (StatusCode::NOT_FOUND, "nothing to see here")
+}
+
+// handle errors by converting them into something that implements `IntoResponse`
+// TODO: use this
+async fn _handle_anyhow_error(err: anyhow::Error) -> impl IntoResponse {
+    let err = format!("{:?}", err);
+
+    warn!("Responding with error: {}", err);
+
+    let err = JsonRpcForwardedResponse {
+        jsonrpc: "2.0".to_string(),
+        // TODO: what id can we use? how do we make sure the incoming id gets attached to this?
+        id: RawValue::from_string("0".to_string()).unwrap(),
+        result: None,
+        error: Some(JsonRpcErrorData {
+            code: -32099,
+            message: err,
+            data: None,
+        }),
+    };
+
+    (
+        StatusCode::INTERNAL_SERVER_ERROR,
+        serde_json::to_string(&err).unwrap(),
+    )
+}