// Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0. use hyper::{ header::CONTENT_TYPE, service::{make_service_fn, service_fn}, Body, Request, Response, Server, }; use prometheus::{Counter, Encoder, Gauge, HistogramVec, TextEncoder}; use lazy_static::lazy_static; use prometheus::{labels, opts, register_counter, register_gauge, register_histogram_vec}; lazy_static! { static ref HTTP_COUNTER: Counter = register_counter!(opts!( "example_http_requests_total", "Number of HTTP requests made.", labels! {"handler" => "all",} )) .unwrap(); static ref HTTP_BODY_GAUGE: Gauge = register_gauge!(opts!( "example_http_response_size_bytes", "The HTTP response sizes in bytes.", labels! {"handler" => "all",} )) .unwrap(); static ref HTTP_REQ_HISTOGRAM: HistogramVec = register_histogram_vec!( "example_http_request_duration_seconds", "The HTTP request latencies in seconds.", &["handler"] ) .unwrap(); } async fn serve_req(_req: Request) -> Result, hyper::Error> { let encoder = TextEncoder::new(); HTTP_COUNTER.inc(); let timer = HTTP_REQ_HISTOGRAM.with_label_values(&["all"]).start_timer(); let metric_families = prometheus::gather(); let mut buffer = vec![]; encoder.encode(&metric_families, &mut buffer).unwrap(); HTTP_BODY_GAUGE.set(buffer.len() as f64); let response = Response::builder() .status(200) .header(CONTENT_TYPE, encoder.format_type()) .body(Body::from(buffer)) .unwrap(); timer.observe_duration(); Ok(response) } #[tokio::main] async fn main() { let addr = ([127, 0, 0, 1], 9898).into(); println!("Listening on http://{}", addr); let serve_future = Server::bind(&addr).serve(make_service_fn(|_| async { Ok::<_, hyper::Error>(service_fn(serve_req)) })); if let Err(err) = serve_future.await { eprintln!("server error: {}", err); } }