relay_server/endpoints/
forward.rs

1//! Server endpoint that proxies any request to the upstream.
2//!
3//! This endpoint will issue a client request to the upstream and append relay's own headers
4//! (`X-Forwarded-For` and `Sentry-Relay-Id`). The response is then streamed back to the origin.
5
6use std::future::Future;
7use std::sync::LazyLock;
8
9use axum::body::Body;
10use axum::extract::Request;
11use axum::handler::Handler;
12use axum::http::{HeaderMap, HeaderValue, StatusCode, Uri};
13use axum::response::{IntoResponse, Response};
14use relay_common::glob2::GlobMatcher;
15use relay_config::ConfigSnapshot;
16use tower_http::limit::RequestBodyLimitLayer;
17
18use crate::extractors::ForwardedFor;
19use crate::service::ServiceState;
20use crate::services::upstream::Method;
21use crate::utils::ForwardRequest;
22
23/// Root path of all API endpoints.
24const API_PATH: &str = "/api/";
25
26/// Internal implementation of the forward endpoint.
27async fn handle(
28    state: ServiceState,
29    forwarded_for: ForwardedFor,
30    method: Method,
31    uri: Uri,
32    headers: HeaderMap<HeaderValue>,
33    data: Body,
34) -> impl IntoResponse {
35    let config = state.config();
36
37    if !config.http_forward() {
38        return StatusCode::NOT_FOUND.into_response();
39    }
40
41    // The `/api/` path is special as it is actually a web UI endpoint. Therefore, reject requests
42    // that either go to the API root or point outside the API.
43    if uri.path() == API_PATH || !uri.path().starts_with(API_PATH) {
44        return StatusCode::NOT_FOUND.into_response();
45    }
46
47    ForwardRequest::builder(method, uri.to_string())
48        .with_name("forward")
49        .with_headers(headers)
50        .with_forwarded_for(forwarded_for)
51        .with_body(data)
52        .with_config(&config)
53        .send_to(state.upstream_relay())
54        .await
55        .into_response()
56}
57
58/// Route classes with request body limit overrides.
59#[derive(Clone, Copy, Debug)]
60enum SpecialRoute {
61    FileUpload,
62    ChunkUpload,
63}
64
65/// Glob matcher for special routes.
66static SPECIAL_ROUTES: LazyLock<GlobMatcher<SpecialRoute>> = LazyLock::new(|| {
67    let mut m = GlobMatcher::new();
68    // file uploads / legacy dsym uploads
69    m.add(
70        "/api/0/projects/*/*/releases/*/files/",
71        SpecialRoute::FileUpload,
72    );
73    m.add(
74        "/api/0/projects/*/*/releases/*/dsyms/",
75        SpecialRoute::FileUpload,
76    );
77    // new chunk uploads
78    m.add(
79        "/api/0/organizations/*/chunk-upload/",
80        SpecialRoute::ChunkUpload,
81    );
82    m
83});
84
85/// Returns the maximum request body size for a route path.
86fn get_limit_for_path(path: &str, config: &ConfigSnapshot) -> usize {
87    match SPECIAL_ROUTES.test(path) {
88        Some(SpecialRoute::FileUpload) => config.max_api_file_upload_size(),
89        Some(SpecialRoute::ChunkUpload) => config.max_api_chunk_upload_size(),
90        None => config.max_api_payload_size(),
91    }
92}
93
94/// Forward endpoint handler.
95///
96/// This endpoint will create a proxy request to the upstream for every incoming request and stream
97/// the request body back to the origin. Regardless of the incoming connection, the connection to
98/// the upstream uses its own HTTP version and transfer encoding.
99///
100/// # Usage
101///
102/// This endpoint is both a handler and a request function:
103///
104/// - Use it as [`Handler`] directly in router methods when registering this as a route.
105/// - Call this manually from other request handlers to conditionally forward from other endpoints.
106pub fn forward(state: ServiceState, req: Request) -> impl Future<Output = Response> {
107    let limit = get_limit_for_path(req.uri().path(), &state.config());
108    handle
109        // `RequestBodyLimitLayer` checks the stream, DefaultBodyLimit does not.
110        .layer(RequestBodyLimitLayer::new(limit))
111        .call(req, state)
112}
relay_server/endpoints/forward.rs

relay_server/endpoints/
forward.rs
