System Initiative

use std::{ fmt, time::Duration, }; use telemetry::{ OtelStatusCode, prelude::*, }; use tower_http::{ LatencyUnit, trace::OnResponse, }; /// An implementation of [`OnResponse`] to update span fields for HTTP responses. #[derive(Clone, Debug)] pub struct HttpOnResponse { level: Level, latency_unit: LatencyUnit, } impl Default for HttpOnResponse { #[inline] fn default() -> Self { Self { level: Level::DEBUG, latency_unit: LatencyUnit::Millis, } } } impl HttpOnResponse { /// Creates a new `HttpOnResponse`. pub fn new() -> Self { Self::default() } /// Sets the [`Level`] used for the tracing [`Span`]. pub fn level(mut self, level: Level) -> Self { self.level = level; self } } impl<B> OnResponse<B> for HttpOnResponse { fn on_response(self, response: &hyper::Response<B>, latency: Duration, span: &Span) { let status = response.status(); span.record("http.response.status_code", status.as_u16()); // TODO(fnichol): set response headers if useful? // In OpenTelemetry HTTP spans, only HTTP/5xx errors should set an `ERROR` value for // `otel.status_code` (except for other errors such as transient/network errors). // // > Span Status MUST be left unset if HTTP status code was in the 1xx, 2xx or 3xx ranges, // > unless there was another error (e.g., network error receiving the response body; or // > 3xx codes with max redirects exceeded), in which case status MUST be set to Error. // // > For HTTP status codes in the 4xx range span status MUST be left unset in case of // > SpanKind.SERVER and MUST be set to Error in case of SpanKind.CLIENT. // // See: <https://opentelemetry.io/docs/specs/semconv/http/http-spans/#status> if status.is_server_error() { span.record("otel.status_code", OtelStatusCode::Error.as_str()); } macro_rules! inner_event { ($level:expr_2021, $($tt:tt)*) => { match $level { ::telemetry::tracing::Level::ERROR => { ::telemetry::tracing::error!($($tt)*); } ::telemetry::tracing::Level::WARN => { ::telemetry::tracing::warn!($($tt)*); } ::telemetry::tracing::Level::INFO => { ::telemetry::tracing::info!($($tt)*); } ::telemetry::tracing::Level::DEBUG => { ::telemetry::tracing::debug!($($tt)*); } ::telemetry::tracing::Level::TRACE => { ::telemetry::tracing::trace!($($tt)*); } } }; } let latency = Latency { unit: self.latency_unit, duration: latency, }; inner_event!( self.level, %latency, status = status.as_u16(), "finished processing request", ); } } // From `tower_http::trace` struct Latency { unit: LatencyUnit, duration: Duration, } impl fmt::Display for Latency { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match self.unit { LatencyUnit::Seconds => write!(f, "{} s", self.duration.as_secs_f64()), LatencyUnit::Millis => write!(f, "{} ms", self.duration.as_millis()), LatencyUnit::Micros => write!(f, "{} μs", self.duration.as_micros()), LatencyUnit::Nanos => write!(f, "{} ns", self.duration.as_nanos()), _ => write!(f, "{:?} (unknown)", self.duration), } } }