Module tracing 

modo::tracing

Tracing initialisation and structured logging for modo applications.

Configures tracing_subscriber at application startup. Call init once from main — typically before starting the HTTP server — and hold the returned TracingGuard for the lifetime of the process.

Provides

Item	Description
Config	Log level, output format, and optional Sentry settings
init	Initialises the global tracing subscriber; returns TracingGuard
TracingGuard	RAII guard that keeps the subscriber (and Sentry client) alive
SentryConfig	Sentry DSN, environment, and sampling rates
info!, debug!, warn!, error!, trace!	Re-exported tracing macros

Log format

The format is selected by Config::format:

Value	Description
"pretty" (default)	Human-readable multi-line output
"json"	Machine-readable JSON, one object per line
anything else	Compact single-line output

The active log level is read from the RUST_LOG environment variable when present; otherwise Config::level is used.

Sentry integration

Sentry support is always compiled in. Populate SentryConfig inside Config::sentry with a non-empty DSN to enable error and performance reporting at runtime. The Sentry SDK is initialised inside init and flushed when the TracingGuard is shut down. When the DSN is empty or the sentry section is omitted, Sentry is silently skipped.

HTTP request spans

This module only handles subscriber setup. HTTP request/response spans are produced by crate::middleware::tracing, which wires a tower_http::trace::TraceLayer with a ModoMakeSpan that pre-declares a tenant_id field (initially empty) so the tenant middleware can later record it via span.record("tenant_id", ...). All tracing field names use snake_case (user_id, session_id, job_id, etc.).

Quick start

use modo::config::load;
use modo::Config;
use modo::runtime::Task;

#[tokio::main]
async fn main() -> modo::Result<()> {
    let config: Config = load("config/").unwrap();
    let guard = modo::tracing::init(&config.tracing)?;

    // ... start server, then on shutdown:
    guard.shutdown().await
}

Macros

debug

Constructs an event at the debug level.

error

Constructs an event at the error level.

info

Constructs an event at the info level.

trace

Constructs an event at the trace level.

warn

Constructs an event at the warn level.

Structs

Config

Configuration for the tracing subscriber.

SentryConfig

Sentry error and performance reporting settings.

TracingGuard

RAII guard that keeps the tracing subscriber and Sentry client alive.

Functions

init

Initialise the global tracing subscriber.