1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161
use super::{Latency, DEFAULT_MESSAGE_LEVEL};
use crate::LatencyUnit;
use http::Response;
use std::time::Duration;
use tracing::Level;
use tracing::Span;
/// Trait used to tell [`Trace`] what to do when a response has been produced.
///
/// See the [module docs](../trace/index.html#on_response) for details on exactly when the
/// `on_response` callback is called.
///
/// [`Trace`]: super::Trace
pub trait OnResponse<B> {
/// Do the thing.
///
/// `latency` is the duration since the request was received.
///
/// `span` is the `tracing` [`Span`], corresponding to this request, produced by the closure
/// passed to [`TraceLayer::make_span_with`]. It can be used to [record field values][record]
/// that weren't known when the span was created.
///
/// [`Span`]: https://docs.rs/tracing/latest/tracing/span/index.html
/// [record]: https://docs.rs/tracing/latest/tracing/span/struct.Span.html#method.record
/// [`TraceLayer::make_span_with`]: crate::trace::TraceLayer::make_span_with
fn on_response(self, response: &Response<B>, latency: Duration, span: &Span);
}
impl<B> OnResponse<B> for () {
#[inline]
fn on_response(self, _: &Response<B>, _: Duration, _: &Span) {}
}
impl<B, F> OnResponse<B> for F
where
F: FnOnce(&Response<B>, Duration, &Span),
{
fn on_response(self, response: &Response<B>, latency: Duration, span: &Span) {
self(response, latency, span)
}
}
/// The default [`OnResponse`] implementation used by [`Trace`].
///
/// [`Trace`]: super::Trace
#[derive(Clone, Debug)]
pub struct DefaultOnResponse {
level: Level,
latency_unit: LatencyUnit,
include_headers: bool,
}
impl Default for DefaultOnResponse {
fn default() -> Self {
Self {
level: DEFAULT_MESSAGE_LEVEL,
latency_unit: LatencyUnit::Millis,
include_headers: false,
}
}
}
impl DefaultOnResponse {
/// Create a new `DefaultOnResponse`.
pub fn new() -> Self {
Self::default()
}
/// Set the [`Level`] used for [tracing events].
///
/// Please note that while this will set the level for the tracing events
/// themselves, it might cause them to lack expected information, like
/// request method or path. You can address this using
/// [`DefaultMakeSpan::level`].
///
/// Defaults to [`Level::DEBUG`].
///
/// [tracing events]: https://docs.rs/tracing/latest/tracing/#events
/// [`DefaultMakeSpan::level`]: crate::trace::DefaultMakeSpan::level
pub fn level(mut self, level: Level) -> Self {
self.level = level;
self
}
/// Set the [`LatencyUnit`] latencies will be reported in.
///
/// Defaults to [`LatencyUnit::Millis`].
pub fn latency_unit(mut self, latency_unit: LatencyUnit) -> Self {
self.latency_unit = latency_unit;
self
}
/// Include response headers on the [`Event`].
///
/// By default headers are not included.
///
/// [`Event`]: tracing::Event
pub fn include_headers(mut self, include_headers: bool) -> Self {
self.include_headers = include_headers;
self
}
}
impl<B> OnResponse<B> for DefaultOnResponse {
fn on_response(self, response: &Response<B>, latency: Duration, _: &Span) {
let latency = Latency {
unit: self.latency_unit,
duration: latency,
};
let response_headers = self
.include_headers
.then(|| tracing::field::debug(response.headers()));
event_dynamic_lvl!(
self.level,
%latency,
status = status(response),
response_headers,
"finished processing request"
);
}
}
fn status<B>(res: &Response<B>) -> Option<i32> {
use crate::classify::grpc_errors_as_failures::ParsedGrpcStatus;
// gRPC-over-HTTP2 uses the "application/grpc[+format]" content type, and gRPC-Web uses
// "application/grpc-web[+format]" or "application/grpc-web-text[+format]", where "format" is
// the message format, e.g. +proto, +json.
//
// So, valid grpc content types include (but are not limited to):
// - application/grpc
// - application/grpc+proto
// - application/grpc-web+proto
// - application/grpc-web-text+proto
//
// For simplicity, we simply check that the content type starts with "application/grpc".
let is_grpc = res
.headers()
.get(http::header::CONTENT_TYPE)
.map_or(false, |value| {
value.as_bytes().starts_with("application/grpc".as_bytes())
});
if is_grpc {
match crate::classify::grpc_errors_as_failures::classify_grpc_metadata(
res.headers(),
crate::classify::GrpcCode::Ok.into_bitmask(),
) {
ParsedGrpcStatus::Success
| ParsedGrpcStatus::HeaderNotString
| ParsedGrpcStatus::HeaderNotInt => Some(0),
ParsedGrpcStatus::NonSuccess(status) => Some(status.get()),
// if `grpc-status` is missing then its a streaming response and there is no status
// _yet_, so its neither success nor error
ParsedGrpcStatus::GrpcStatusHeaderMissing => None,
}
} else {
Some(res.status().as_u16().into())
}
}