use std::net::SocketAddr; use std::sync::Arc; use async_trait::async_trait; use futures::future::Future; use hyper::header::HeaderValue; use hyper::server::conn::AddrStream; use hyper::service::{make_service_fn, service_fn}; use hyper::{Body, Request, Response, Server}; use hyper::{HeaderMap, StatusCode}; use opentelemetry::{ global, metrics::{Counter, ValueRecorder}, trace::{FutureExt, SpanRef, TraceContextExt, Tracer}, Context, KeyValue, }; use garage_util::error::Error as GarageError; use garage_util::metrics::{gen_trace_id, RecordDuration}; pub(crate) trait ApiEndpoint: Send + Sync + 'static { fn name(&self) -> &'static str; fn add_span_attributes(&self, span: SpanRef<'_>); } pub trait ApiError: std::error::Error + Send + Sync + 'static { fn http_status_code(&self) -> StatusCode; fn add_http_headers(&self, header_map: &mut HeaderMap<HeaderValue>); fn http_body(&self, garage_region: &str, path: &str) -> Body; } #[async_trait] pub(crate) trait ApiHandler: Send + Sync + 'static { const API_NAME: &'static str; const API_NAME_DISPLAY: &'static str; type Endpoint: ApiEndpoint; type Error: ApiError; fn parse_endpoint(&self, r: &Request<Body>) -> Result<Self::Endpoint, Self::Error>; async fn handle( &self, req: Request<Body>, endpoint: Self::Endpoint, ) -> Result<Response<Body>, Self::Error>; } pub(crate) struct ApiServer<A: ApiHandler> { region: String, api_handler: A, // Metrics request_counter: Counter<u64>, error_counter: Counter<u64>, request_duration: ValueRecorder<f64>, } impl<A: ApiHandler> ApiServer<A> { pub fn new(region: String, api_handler: A) -> Arc<Self> { let meter = global::meter("garage/api"); Arc::new(Self { region, api_handler, request_counter: meter .u64_counter(format!("api.{}.request_counter", A::API_NAME)) .with_description(format!( "Number of API calls to the various {} API endpoints", A::API_NAME_DISPLAY )) .init(), error_counter: meter .u64_counter(format!("api.{}.error_counter", A::API_NAME)) .with_description(format!( "Number of API calls to the various {} API endpoints that resulted in errors", A::API_NAME_DISPLAY )) .init(), request_duration: meter .f64_value_recorder(format!("api.{}.request_duration", A::API_NAME)) .with_description(format!( "Duration of API calls to the various {} API endpoints", A::API_NAME_DISPLAY )) .init(), }) } pub async fn run_server( self: Arc<Self>, bind_addr: SocketAddr, shutdown_signal: impl Future<Output = ()>, ) -> Result<(), GarageError> { let service = make_service_fn(|conn: &AddrStream| { let this = self.clone(); let client_addr = conn.remote_addr(); async move { Ok::<_, GarageError>(service_fn(move |req: Request<Body>| { let this = this.clone(); this.handler(req, client_addr) })) } }); let server = Server::bind(&bind_addr).serve(service); let graceful = server.with_graceful_shutdown(shutdown_signal); info!( "{} API server listening on http://{}", A::API_NAME_DISPLAY, bind_addr ); graceful.await?; Ok(()) } async fn handler( self: Arc<Self>, req: Request<Body>, addr: SocketAddr, ) -> Result<Response<Body>, GarageError> { let uri = req.uri().clone(); let has_forwarded_for_header = req.headers().contains_key("x-forwarded-for"); if has_forwarded_for_header { let forwarded_for_ip_addr = &req .headers() .get("x-forwarded-for") .expect("Could not parse X-Forwarded-For header") .to_str() .unwrap_or_default(); info!( "{} (via {}) {} {}", forwarded_for_ip_addr, addr, req.method(), uri ); } else { info!("{} {} {}", addr, req.method(), uri); } debug!("{:?}", req); let tracer = opentelemetry::global::tracer("garage"); let span = tracer .span_builder(format!("{} API call (unknown)", A::API_NAME_DISPLAY)) .with_trace_id(gen_trace_id()) .with_attributes(vec![ KeyValue::new("method", format!("{}", req.method())), KeyValue::new("uri", req.uri().to_string()), ]) .start(&tracer); let res = self .handler_stage2(req) .with_context(Context::current_with_span(span)) .await; match res { Ok(x) => { debug!("{} {:?}", x.status(), x.headers()); Ok(x) } Err(e) => { let body: Body = e.http_body(&self.region, uri.path()); let mut http_error_builder = Response::builder().status(e.http_status_code()); if let Some(header_map) = http_error_builder.headers_mut() { e.add_http_headers(header_map) } let http_error = http_error_builder.body(body)?; if e.http_status_code().is_server_error() { warn!("Response: error {}, {}", e.http_status_code(), e); } else { info!("Response: error {}, {}", e.http_status_code(), e); } Ok(http_error) } } } async fn handler_stage2(&self, req: Request<Body>) -> Result<Response<Body>, A::Error> { let endpoint = self.api_handler.parse_endpoint(&req)?; debug!("Endpoint: {}", endpoint.name()); let current_context = Context::current(); let current_span = current_context.span(); current_span.update_name::<String>(format!( "{} API {}", A::API_NAME_DISPLAY, endpoint.name() )); current_span.set_attribute(KeyValue::new("endpoint", endpoint.name())); endpoint.add_span_attributes(current_span); let metrics_tags = &[KeyValue::new("api_endpoint", endpoint.name())]; let res = self .api_handler .handle(req, endpoint) .record_duration(&self.request_duration, &metrics_tags[..]) .await; self.request_counter.add(1, &metrics_tags[..]); let status_code = match &res { Ok(r) => r.status(), Err(e) => e.http_status_code(), }; if status_code.is_client_error() || status_code.is_server_error() { self.error_counter.add( 1, &[ metrics_tags[0].clone(), KeyValue::new("status_code", status_code.as_str().to_string()), ], ); } res } }