use axum::headers::HeaderName; use axum::http::HeaderValue; use axum::response::{IntoResponse, Response}; use axum::{routing::get, Extension, Router}; use std::net::SocketAddr; use std::sync::atomic::Ordering; use std::sync::Arc; use tokio::sync::broadcast; use tracing::info; use crate::app::App; use crate::errors::Web3ProxyResult; /// Run a prometheus metrics server on the given port. pub async fn serve( app: Arc, mut shutdown_receiver: broadcast::Receiver<()>, ) -> Web3ProxyResult<()> { // routes should be ordered most to least common let router = Router::new() .route("/", get(root)) .layer(Extension(app.clone())); // note: the port here might be 0 let port = app.prometheus_port.load(Ordering::Relaxed); // TODO: config for the host? let addr = SocketAddr::from(([0, 0, 0, 0], port)); let service = router.into_make_service(); // `axum::Server` is a re-export of `hyper::Server` let server = axum::Server::bind(&addr).serve(service); let port = server.local_addr().port(); info!("prometheus listening on port {}", port); app.prometheus_port.store(port, Ordering::Relaxed); server .with_graceful_shutdown(async move { let _ = shutdown_receiver.recv().await; }) .await .map_err(Into::into) } async fn root(Extension(app): Extension>) -> Response { let serialized = app.prometheus_metrics().await; let mut r = serialized.into_response(); // // TODO: is there an easier way to do this? r.headers_mut().insert( HeaderName::from_static("content-type"), HeaderValue::from_static("application/openmetrics-text; version=1.0.0; charset=utf-8"), ); r }