// This file is part of Substrate. // Copyright (C) 2019-2021 Parity Technologies (UK) Ltd. // SPDX-License-Identifier: Apache-2.0 // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. use futures_util::{future::Future, FutureExt}; pub use prometheus::{ self, core::{ AtomicF64 as F64, AtomicI64 as I64, AtomicU64 as U64, GenericCounter as Counter, GenericCounterVec as CounterVec, GenericGauge as Gauge, GenericGaugeVec as GaugeVec, }, exponential_buckets, Error as PrometheusError, Histogram, HistogramOpts, HistogramVec, Opts, Registry, }; use prometheus::{core::Collector, Encoder, TextEncoder}; use std::net::SocketAddr; #[cfg(not(target_os = "unknown"))] mod networking; mod sourced; pub use sourced::{MetricSource, SourcedCounter, SourcedGauge, SourcedMetric}; #[cfg(not(target_os = "unknown"))] pub use known_os::init_prometheus; #[cfg(target_os = "unknown")] pub use unknown_os::init_prometheus; pub fn register( metric: T, registry: &Registry, ) -> Result { registry.register(Box::new(metric.clone()))?; Ok(metric) } // On WASM `init_prometheus` becomes a no-op. #[cfg(target_os = "unknown")] mod unknown_os { use super::*; pub enum Error {} pub async fn init_prometheus(_: SocketAddr, _registry: Registry) -> Result<(), Error> { Ok(()) } } #[cfg(not(target_os = "unknown"))] mod known_os { use super::*; use hyper::{ http::StatusCode, service::{make_service_fn, service_fn}, Body, Request, Response, Server, }; #[derive(Debug, derive_more::Display, derive_more::From)] pub enum Error { /// Hyper internal error. Hyper(hyper::Error), /// Http request error. Http(hyper::http::Error), /// i/o error. Io(std::io::Error), #[display(fmt = "Prometheus port {} already in use.", _0)] PortInUse(SocketAddr), } impl std::error::Error for Error { fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { match self { Error::Hyper(error) => Some(error), Error::Http(error) => Some(error), Error::Io(error) => Some(error), Error::PortInUse(_) => None, } } } async fn request_metrics( req: Request, registry: Registry, ) -> Result, Error> { if req.uri().path() == "/metrics" { let metric_families = registry.gather(); let mut buffer = vec![]; let encoder = TextEncoder::new(); encoder.encode(&metric_families, &mut buffer).unwrap(); Response::builder() .status(StatusCode::OK) .header("Content-Type", encoder.format_type()) .body(Body::from(buffer)) .map_err(Error::Http) } else { Response::builder() .status(StatusCode::NOT_FOUND) .body(Body::from("Not found.")) .map_err(Error::Http) } } #[derive(Clone)] pub struct Executor; impl hyper::rt::Executor for Executor where T: Future + Send + 'static, T::Output: Send + 'static, { fn execute(&self, future: T) { async_std::task::spawn(future); } } /// Initializes the metrics context, and starts an HTTP server /// to serve metrics. pub async fn init_prometheus( prometheus_addr: SocketAddr, registry: Registry, ) -> Result<(), Error> { use networking::Incoming; let listener = async_std::net::TcpListener::bind(&prometheus_addr) .await .map_err(|_| Error::PortInUse(prometheus_addr))?; log::info!("〽️ Prometheus exporter started at {}", prometheus_addr); let service = make_service_fn(move |_| { let registry = registry.clone(); async move { Ok::<_, hyper::Error>(service_fn(move |req: Request| { request_metrics(req, registry.clone()) })) } }); let server = Server::builder(Incoming(listener.incoming())) .executor(Executor) .serve(service) .boxed(); let result = server.await.map_err(Into::into); result } }