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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
//! [`tracing`] filters.
//!
//! [`tracing`] is a framework for instrumenting Rust programs to
//! collect scoped, structured, and async-aware diagnostics. This module
//! provides a set of filters for instrumenting Warp applications with `tracing`
//! spans. [`Spans`] can be used to associate individual events  with a request,
//! and track contexts through the application.
//!
//! [`tracing`]: https://crates.io/tracing
//! [`Spans`]: https://docs.rs/tracing/latest/tracing/#spans
use tracing::Span;

use std::net::SocketAddr;

use http::{self, header};

use crate::filter::{Filter, WrapSealed};
use crate::reject::IsReject;
use crate::reply::Reply;
use crate::route::Route;

use self::internal::WithTrace;

/// 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());
/// ```
///
/// [`Span`]: https://docs.rs/tracing/latest/tracing/#spans
/// [`INFO`]: https://docs.rs/tracing/0.1.16/tracing/struct.Level.html#associatedconstant.INFO
/// [`DEBUG`]: https://docs.rs/tracing/0.1.16/tracing/struct.Level.html#associatedconstant.DEBUG
pub fn request() -> Trace<impl Fn(Info) -> Span + Clone> {
    use tracing::field::{display, Empty};
    trace(|info: Info| {
        let span = tracing::info_span!(
            "request",
            remote.addr = Empty,
            method = %info.method(),
            path = %info.path(),
            version = ?info.route.version(),
            referer = Empty,
        );

        // Record optional fields.
        if let Some(remote_addr) = info.remote_addr() {
            span.record("remote.addr", &display(remote_addr));
        }

        if let Some(referer) = info.referer() {
            span.record("referer", &display(referer));
        }

        tracing::debug!(parent: &span, "received request");

        span
    })
}

/// Create a wrapping filter that instruments every request with a custom
/// `tracing` [`Span`] provided by a function.
///
///
/// # Example
///
/// ```
/// use warp::Filter;
///
/// let route = warp::any()
///     .map(warp::reply)
///     .with(warp::trace(|info| {
///         // Create a span using tracing macros
///         tracing::info_span!(
///             "request",
///             method = %info.method(),
///             path = %info.path(),
///         )
///     }));
/// ```
///
/// [`Span`]: https://docs.rs/tracing/latest/tracing/#spans
pub fn trace<F>(func: F) -> Trace<F>
where
    F: Fn(Info) -> Span + Clone,
{
    Trace { func }
}

/// Create a wrapping filter that instruments every request with a `tracing`
/// [`Span`] at the [`DEBUG`] level representing a named context.
///
/// This can be used to instrument multiple routes with their own sub-spans in a
/// per-request trace.
///
/// # Example
///
/// ```
/// use warp::Filter;
///
/// let hello = warp::path("hello")
///     .map(warp::reply)
///     .with(warp::trace::named("hello"));
///
/// let goodbye = warp::path("goodbye")
///     .map(warp::reply)
///     .with(warp::trace::named("goodbye"));
///
/// let routes = hello.or(goodbye);
/// ```
///
/// [`Span`]: https://docs.rs/tracing/latest/tracing/#spans
/// [`DEBUG`]: https://docs.rs/tracing/0.1.16/tracing/struct.Level.html#associatedconstant.DEBUG
pub fn named(name: &'static str) -> Trace<impl Fn(Info<'_>) -> Span + Copy> {
    trace(move |_| tracing::debug_span!("context", "{}", name,))
}

/// Decorates a [`Filter`](crate::Filter) to create a [`tracing`] [span] for
/// requests and responses.
///
/// [`tracing`]: https://crates.io/tracing
/// [span]: https://docs.rs/tracing/latest/tracing/#spans
#[derive(Clone, Copy, Debug)]
pub struct Trace<F> {
    func: F,
}

/// Information about the request/response that can be used to prepare log lines.
#[allow(missing_debug_implementations)]
pub struct Info<'a> {
    route: &'a Route,
}

impl<FN, F> WrapSealed<F> for Trace<FN>
where
    FN: Fn(Info) -> Span + Clone + Send,
    F: Filter + Clone + Send,
    F::Extract: Reply,
    F::Error: IsReject,
{
    type Wrapped = WithTrace<FN, F>;

    fn wrap(&self, filter: F) -> Self::Wrapped {
        WithTrace {
            filter,
            trace: self.clone(),
        }
    }
}

impl<'a> Info<'a> {
    /// View the remote `SocketAddr` of the request.
    pub fn remote_addr(&self) -> Option<SocketAddr> {
        self.route.remote_addr()
    }

    /// View the `http::Method` of the request.
    pub fn method(&self) -> &http::Method {
        self.route.method()
    }

    /// View the URI path of the request.
    pub fn path(&self) -> &str {
        self.route.full_path()
    }

    /// View the `http::Version` of the request.
    pub fn version(&self) -> http::Version {
        self.route.version()
    }

    /// View the referer of the request.
    pub fn referer(&self) -> Option<&str> {
        self.route
            .headers()
            .get(header::REFERER)
            .and_then(|v| v.to_str().ok())
    }

    /// View the user agent of the request.
    pub fn user_agent(&self) -> Option<&str> {
        self.route
            .headers()
            .get(header::USER_AGENT)
            .and_then(|v| v.to_str().ok())
    }

    /// View the host of the request
    pub fn host(&self) -> Option<&str> {
        self.route
            .headers()
            .get(header::HOST)
            .and_then(|v| v.to_str().ok())
    }

    /// View the request headers.
    pub fn request_headers(&self) -> &http::HeaderMap {
        self.route.headers()
    }
}

mod internal {
    use futures::{future::Inspect, future::MapOk, FutureExt, TryFutureExt};

    use super::{Info, Trace};
    use crate::filter::{Filter, FilterBase, Internal};
    use crate::reject::IsReject;
    use crate::reply::Reply;
    use crate::reply::Response;
    use crate::route;

    #[allow(missing_debug_implementations)]
    pub struct Traced(pub(super) Response);

    impl Reply for Traced {
        #[inline]
        fn into_response(self) -> Response {
            self.0
        }
    }

    #[allow(missing_debug_implementations)]
    #[derive(Clone, Copy)]
    pub struct WithTrace<FN, F> {
        pub(super) filter: F,
        pub(super) trace: Trace<FN>,
    }

    use tracing::instrument::{Instrument, Instrumented};
    use tracing::Span;

    fn finished_logger<E: IsReject>(reply: &Result<(Traced,), E>) {
        match reply {
            Ok((Traced(resp),)) => {
                tracing::info!(target: "warp::filters::trace", status = resp.status().as_u16(), "finished processing with success");
            }
            Err(e) if e.status().is_server_error() => {
                tracing::error!(
                    target: "warp::filters::trace",
                    status = e.status().as_u16(),
                    error = ?e,
                    "unable to process request (internal error)"
                );
            }
            Err(e) if e.status().is_client_error() => {
                tracing::warn!(
                    target: "warp::filters::trace",
                    status = e.status().as_u16(),
                    error = ?e,
                    "unable to serve request (client error)"
                );
            }
            Err(e) => {
                // Either informational or redirect
                tracing::info!(
                    target: "warp::filters::trace",
                    status = e.status().as_u16(),
                    result = ?e,
                    "finished processing with status"
                );
            }
        }
    }

    fn convert_reply<R: Reply>(reply: R) -> (Traced,) {
        (Traced(reply.into_response()),)
    }

    impl<FN, F> FilterBase for WithTrace<FN, F>
    where
        FN: Fn(Info) -> Span + Clone + Send,
        F: Filter + Clone + Send,
        F::Extract: Reply,
        F::Error: IsReject,
    {
        type Extract = (Traced,);
        type Error = F::Error;
        type Future = Instrumented<
            Inspect<
                MapOk<F::Future, fn(F::Extract) -> Self::Extract>,
                fn(&Result<Self::Extract, F::Error>),
            >,
        >;

        fn filter(&self, _: Internal) -> Self::Future {
            let span = route::with(|route| (self.trace.func)(Info { route }));
            let _entered = span.enter();

            tracing::info!(target: "warp::filters::trace", "processing request");
            self.filter
                .filter(Internal)
                .map_ok(convert_reply as fn(F::Extract) -> Self::Extract)
                .inspect(finished_logger as fn(&Result<Self::Extract, F::Error>))
                .instrument(span.clone())
        }
    }
}