tailtriage_axum/
lib.rs

1#![doc = include_str!("../README.md")]
2#![warn(missing_docs)]
3
4//! Axum adoption helpers layered on top of `tailtriage-core`.
5//!
6//! This crate provides a focused middleware + extractor path so handlers can
7//! access request instrumentation without repeating request start/finish wiring.
8
9use std::sync::Arc;
10
11use axum::extract::{FromRequestParts, MatchedPath, State};
12use axum::http::request::Parts;
13use axum::http::{Request, StatusCode};
14use axum::middleware::Next;
15use axum::response::IntoResponse;
16use tailtriage_core::{Outcome, OwnedRequestHandle, RequestOptions, Tailtriage};
17
18/// Returns the crate name for smoke-testing workspace wiring.
19#[must_use]
20pub const fn crate_name() -> &'static str {
21    "tailtriage-axum"
22}
23
24/// Middleware that starts and finishes one tailtriage request per axum request.
25///
26/// Use this with `axum::middleware::from_fn_with_state` and pass the same
27/// `Arc<Tailtriage>` in middleware state.
28pub async fn middleware(
29    State(tailtriage): State<Arc<Tailtriage>>,
30    mut request: Request<axum::body::Body>,
31    next: Next,
32) -> axum::response::Response {
33    let route = request_route_label(&request);
34    let started = tailtriage.begin_request_with_owned(route, RequestOptions::new().kind("http"));
35
36    request
37        .extensions_mut()
38        .insert(TailtriageRequest(started.handle.clone()));
39
40    let response = next.run(request).await;
41    let status = response.status();
42
43    started.completion.finish(status_to_outcome(status));
44    response
45}
46
47/// Handler extractor for the request-scoped instrumentation handle.
48#[derive(Debug, Clone)]
49pub struct TailtriageRequest(pub OwnedRequestHandle);
50
51impl TailtriageRequest {
52    /// Returns the wrapped request handle.
53    #[must_use]
54    pub fn into_inner(self) -> OwnedRequestHandle {
55        self.0
56    }
57}
58
59impl<S> FromRequestParts<S> for TailtriageRequest
60where
61    S: Send + Sync,
62{
63    type Rejection = TailtriageExtractorError;
64
65    async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
66        parts
67            .extensions
68            .get::<TailtriageRequest>()
69            .cloned()
70            .ok_or(TailtriageExtractorError)
71    }
72}
73
74/// Rejection returned when `TailtriageRequest` is used without middleware.
75#[derive(Debug, Clone, Copy)]
76pub struct TailtriageExtractorError;
77
78impl IntoResponse for TailtriageExtractorError {
79    fn into_response(self) -> axum::response::Response {
80        (
81            StatusCode::INTERNAL_SERVER_ERROR,
82            "tailtriage extractor missing. Add tailtriage_axum::middleware.",
83        )
84            .into_response()
85    }
86}
87
88fn request_route_label(request: &Request<axum::body::Body>) -> String {
89    request
90        .extensions()
91        .get::<MatchedPath>()
92        .map_or_else(|| request.uri().path(), MatchedPath::as_str)
93        .to_owned()
94}
95
96fn status_to_outcome(status: StatusCode) -> Outcome {
97    if status.is_server_error() {
98        Outcome::Error
99    } else {
100        Outcome::Ok
101    }
102}
103
104#[cfg(test)]
105mod tests {
106    use super::{crate_name, status_to_outcome};
107
108    #[test]
109    fn crate_name_is_stable() {
110        assert_eq!(crate_name(), "tailtriage-axum");
111    }
112
113    #[test]
114    fn maps_server_errors_to_error_outcome() {
115        assert_eq!(
116            status_to_outcome(axum::http::StatusCode::INTERNAL_SERVER_ERROR),
117            tailtriage_core::Outcome::Error
118        );
119        assert_eq!(
120            status_to_outcome(axum::http::StatusCode::BAD_REQUEST),
121            tailtriage_core::Outcome::Ok
122        );
123    }
124}
tailtriage_axum/lib.rs

tailtriage_axum/
lib.rs
