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 cfg_if::cfg_if;
15use std::net::SocketAddr;
16use tokio::net::TcpListener;
17use tracing::Level;
18use tracing_subscriber::{layer::SubscriberExt, Layer, Registry};
19
20/// Logging configuration.
21pub struct Logging {
22    /// The level of logging to use.
23    pub level: Level,
24
25    /// Whether to log in JSON format.
26    ///
27    /// This is useful for structured logging in server-based environments.
28    /// If you are running things locally, it is recommended to use
29    /// `json = false` to get a human-readable format.
30    pub json: bool,
31}
32
33/// Initialize telemetry with the given configuration.
34///
35/// If `metrics` is provided, starts serving metrics at the given address at `/metrics`.
36/// If `traces` is provided, enables OpenTelemetry trace export.
37pub fn init(
38    context: Context,
39    logging: Logging,
40    metrics: Option<SocketAddr>,
41    traces: Option<Config>,
42) {
43    // Create a filter layer to set the maximum level to INFO
44    let filter = tracing_subscriber::EnvFilter::new(logging.level.to_string());
45
46    // Create fmt layer for logging
47    let log_layer = tracing_subscriber::fmt::layer()
48        .with_line_number(true)
49        .with_thread_ids(true)
50        .with_file(true)
51        .with_span_events(tracing_subscriber::fmt::format::FmtSpan::CLOSE);
52
53    // Set the format to JSON (if specified)
54    let log_layer = if logging.json {
55        log_layer.json().boxed()
56    } else {
57        log_layer.compact().boxed()
58    };
59
60    // Create OpenTelemetry layer for tracing
61    let trace_layer = traces.map(|cfg| {
62        let tracer = export(cfg).expect("Failed to initialize tracer");
63        tracing_opentelemetry::layer().with_tracer(tracer)
64    });
65
66    // Create tracing registry.
67    cfg_if! {
68        if #[cfg(feature = "tokio-console")] {
69            let console_layer = console_subscriber::spawn();
70            let registry = Registry::default()
71                .with(filter)
72                .with(log_layer)
73                .with(trace_layer)
74                .with(console_layer);
75        } else {
76            let registry = Registry::default()
77                .with(filter)
78                .with(log_layer)
79                .with(trace_layer);
80        }
81    }
82
83    // Set the global subscriber
84    tracing::subscriber::set_global_default(registry).expect("Failed to set subscriber");
85
86    // Expose metrics over HTTP
87    if let Some(cfg) = metrics {
88        context
89            .with_label("metrics")
90            .spawn(move |context| async move {
91                // Create a tokio listener for the metrics server.
92                //
93                // We explicitly avoid using a runtime `Listener` because
94                // it will track bandwidth used for metrics and apply a policy
95                // for read/write timeouts fit for a p2p network.
96                let listener = TcpListener::bind(cfg)
97                    .await
98                    .expect("Failed to bind metrics server");
99
100                // Create a router for the metrics server
101                let app = Router::new()
102                    .route(
103                        "/metrics",
104                        get(|Extension(ctx): Extension<Context>| async move {
105                            Response::builder()
106                                .status(StatusCode::OK)
107                                .header(header::CONTENT_TYPE, "text/plain; version=0.0.4")
108                                .body(Body::from(ctx.encode()))
109                                .expect("Failed to create response")
110                        }),
111                    )
112                    .layer(Extension(context));
113
114                // Serve the metrics over HTTP.
115                //
116                // `serve` will spawn its own tasks using `tokio::spawn` (and there is no way to specify
117                // it to do otherwise). These tasks will not be tracked like metrics spawned using `Spawner`.
118                serve(listener, app.into_make_service())
119                    .await
120                    .expect("Could not serve metrics");
121            });
122    }
123}
commonware_runtime/tokio/telemetry.rs

commonware_runtime/tokio/
telemetry.rs
