use crate::{success_response, ApiError, ApiResult, DBPath}; use beacon_chain::{BeaconChain, BeaconChainTypes}; use hyper::{Body, Request}; use prometheus::{Encoder, TextEncoder}; use std::sync::Arc; pub use lighthouse_metrics::*; lazy_static! { pub static ref REQUEST_RESPONSE_TIME: Result = try_create_histogram( "http_server_request_duration_seconds", "Time taken to build a response to a HTTP request" ); pub static ref REQUEST_COUNT: Result = try_create_int_counter( "http_server_request_total", "Total count of HTTP requests received" ); pub static ref SUCCESS_COUNT: Result = try_create_int_counter( "http_server_success_total", "Total count of HTTP 200 responses sent" ); } /// Returns the full set of Prometheus metrics for the Beacon Node application. /// /// # Note /// /// This is a HTTP handler method. pub fn get_prometheus(req: Request) -> ApiResult { let mut buffer = vec![]; let encoder = TextEncoder::new(); let beacon_chain = req .extensions() .get::>>() .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".to_string()))?; let db_path = req .extensions() .get::() .ok_or_else(|| ApiError::ServerError("DBPath extension missing".to_string()))?; // There are two categories of metrics: // // - Dynamically updated: things like histograms and event counters that are updated on the // fly. // - Statically updated: things which are only updated at the time of the scrape (used where we // can avoid cluttering up code with metrics calls). // // The `lighthouse_metrics` crate has a `DEFAULT_REGISTRY` global singleton (via `lazy_static`) // which keeps the state of all the metrics. Dynamically updated things will already be // up-to-date in the registry (because they update themselves) however statically updated // things need to be "scraped". // // We proceed by, first updating all the static metrics using `scrape_for_metrics(..)`. Then, // using `lighthouse_metrics::gather(..)` to collect the global `DEFAULT_REGISTRY` metrics into // a string that can be returned via HTTP. slot_clock::scrape_for_metrics::(&beacon_chain.slot_clock); store::scrape_for_metrics(&db_path); beacon_chain::scrape_for_metrics(&beacon_chain); encoder .encode(&lighthouse_metrics::gather(), &mut buffer) .unwrap(); String::from_utf8(buffer) .map(|string| success_response(Body::from(string))) .map_err(|e| ApiError::ServerError(format!("Failed to encode prometheus info: {:?}", e))) }