Expand description
Create a wrapping filter that instruments every request with a tracing
Span
at the INFO
level, containing a summary of the request.
Additionally, if the DEBUG
level is enabled, the span will contain an
event recording the request’s headers.
Example
use warp::Filter;
let route = warp::any()
.map(warp::reply)
.with(warp::trace::request());
Examples found in repository?
examples/tracing.rs (line 56)
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async fn main() {
// Filter traces based on the RUST_LOG env var, or, if it's not set,
// default to show the output of the example.
let filter = std::env::var("RUST_LOG").unwrap_or_else(|_| "tracing=info,warp=debug".to_owned());
// Configure the default `tracing` subscriber.
// The `fmt` subscriber from the `tracing-subscriber` crate logs `tracing`
// events to stdout. Other subscribers are available for integrating with
// distributed tracing systems such as OpenTelemetry.
tracing_subscriber::fmt()
// Use the filter we built above to determine which traces to record.
.with_env_filter(filter)
// Record an event when each span closes. This can be used to time our
// routes' durations!
.with_span_events(FmtSpan::CLOSE)
.init();
let hello = warp::path("hello")
.and(warp::get())
// When the `hello` route is called, emit a `tracing` event.
.map(|| {
tracing::info!("saying hello...");
"Hello, World!"
})
// Wrap the route in a `tracing` span to add the route's name as context
// to any events that occur inside it.
.with(warp::trace::named("hello"));
let goodbye = warp::path("goodbye")
.and(warp::get())
.map(|| {
tracing::info!("saying goodbye...");
"So long and thanks for all the fish!"
})
// We can also provide our own custom `tracing` spans to wrap a route.
.with(warp::trace(|info| {
// Construct our own custom span for this route.
tracing::info_span!("goodbye", req.path = ?info.path())
}));
let routes = hello
.or(goodbye)
// Wrap all the routes with a filter that creates a `tracing` span for
// each request we receive, including data about the request.
.with(warp::trace::request());
warp::serve(routes).run(([127, 0, 0, 1], 3030)).await;
}