commonware_runtime/tokio/
telemetry.rs

1//! Utilities for collecting and reporting telemetry data.
2
3use super::{
4    tracing::{export, Config},
5    Context,
6};
7use crate::{Metrics, Spawner};
8use axum::{
9    body::Body,
10    http::{header, Response, StatusCode},
11    routing::get,
12    serve, Extension, Router,
13};
14use std::net::SocketAddr;
15use tokio::net::TcpListener;
16use tracing::Level;
17use tracing_subscriber::{layer::SubscriberExt, Layer, Registry};
18
19/// Logging configuration.
20pub struct Logging {
21    /// The level of logging to use.
22    pub level: Level,
23
24    /// Whether to log in JSON format.
25    ///
26    /// This is useful for structured logging in server-based environments.
27    /// If you are running things locally, it is recommended to use
28    /// `json = false` to get a human-readable format.
29    pub json: bool,
30}
31
32/// Initialize telemetry with the given configuration.
33///
34/// If `metrics` is provided, starts serving metrics at the given address at `/metrics`.
35/// If `traces` is provided, enables OpenTelemetry trace export.
36pub fn init(
37    context: Context,
38    logging: Logging,
39    metrics: Option<SocketAddr>,
40    traces: Option<Config>,
41) {
42    // Create a filter layer to set the maximum level to INFO
43    let filter = tracing_subscriber::EnvFilter::new(logging.level.to_string());
44
45    // Create fmt layer for logging
46    let log_layer = tracing_subscriber::fmt::layer()
47        .with_line_number(true)
48        .with_thread_ids(true)
49        .with_file(true)
50        .with_span_events(tracing_subscriber::fmt::format::FmtSpan::CLOSE);
51
52    // Set the format to JSON (if specified)
53    let log_layer = if logging.json {
54        log_layer.json().boxed()
55    } else {
56        log_layer.compact().boxed()
57    };
58
59    // Create OpenTelemetry layer for tracing
60    let trace_layer = traces.map(|cfg| {
61        let tracer = export(cfg).expect("Failed to initialize tracer");
62        tracing_opentelemetry::layer().with_tracer(tracer)
63    });
64
65    // Set the global subscriber
66    let registry = Registry::default()
67        .with(filter)
68        .with(log_layer)
69        .with(trace_layer);
70    tracing::subscriber::set_global_default(registry).expect("Failed to set subscriber");
71
72    // Expose metrics over HTTP
73    if let Some(cfg) = metrics {
74        context
75            .with_label("metrics")
76            .spawn(move |context| async move {
77                // Create a tokio listener for the metrics server.
78                //
79                // We explicitly avoid using a runtime `Listener` because
80                // it will track bandwidth used for metrics and apply a policy
81                // for read/write timeouts fit for a p2p network.
82                let listener = TcpListener::bind(cfg)
83                    .await
84                    .expect("Failed to bind metrics server");
85
86                // Create a router for the metrics server
87                let app = Router::new()
88                    .route(
89                        "/metrics",
90                        get(|Extension(ctx): Extension<Context>| async move {
91                            Response::builder()
92                                .status(StatusCode::OK)
93                                .header(header::CONTENT_TYPE, "text/plain; version=0.0.4")
94                                .body(Body::from(ctx.encode()))
95                                .expect("Failed to create response")
96                        }),
97                    )
98                    .layer(Extension(context));
99
100                // Serve the metrics over HTTP.
101                //
102                // `serve` will spawn its own tasks using `tokio::spawn` (and there is no way to specify
103                // it to do otherwise). These tasks will not be tracked like metrics spawned using `Spawner`.
104                serve(listener, app.into_make_service())
105                    .await
106                    .expect("Could not serve metrics");
107            });
108    }
109}
commonware_runtime/tokio/telemetry.rs

commonware_runtime/tokio/
telemetry.rs
