Files
letro-authentication-service/crates/http/src/ext.rs
2024-10-28 13:46:38 +01:00

52 lines
1.4 KiB
Rust

// Copyright 2024 New Vector Ltd.
// Copyright 2022-2024 The Matrix.org Foundation C.I.C.
//
// SPDX-License-Identifier: AGPL-3.0-only
// Please see LICENSE in the repository root for full details.
use std::sync::OnceLock;
use http::header::HeaderName;
use tower_http::cors::CorsLayer;
static PROPAGATOR_HEADERS: OnceLock<Vec<HeaderName>> = OnceLock::new();
/// Notify the CORS layer what opentelemetry propagators are being used. This
/// helps whitelisting headers in CORS requests.
///
/// # Panics
///
/// When called twice
pub fn set_propagator(propagator: &dyn opentelemetry::propagation::TextMapPropagator) {
let headers = propagator
.fields()
.map(|h| HeaderName::try_from(h).unwrap())
.collect();
tracing::debug!(
?headers,
"Headers allowed in CORS requests for trace propagators set"
);
PROPAGATOR_HEADERS
.set(headers)
.expect(concat!(module_path!(), "::set_propagator was called twice"));
}
pub trait CorsLayerExt {
#[must_use]
fn allow_otel_headers<H>(self, headers: H) -> Self
where
H: IntoIterator<Item = HeaderName>;
}
impl CorsLayerExt for CorsLayer {
fn allow_otel_headers<H>(self, headers: H) -> Self
where
H: IntoIterator<Item = HeaderName>,
{
let base = PROPAGATOR_HEADERS.get().cloned().unwrap_or_default();
let headers: Vec<_> = headers.into_iter().chain(base).collect();
self.allow_headers(headers)
}
}