Files
sglang/sgl-router/src/routers/header_utils.rs

95 lines
3.3 KiB
Rust

use axum::{body::Body, extract::Request, http::HeaderMap};
/// Copy request headers to a Vec of name-value string pairs
/// Used for forwarding headers to backend workers
pub fn copy_request_headers(req: &Request<Body>) -> Vec<(String, String)> {
req.headers()
.iter()
.filter_map(|(name, value)| {
// Convert header value to string, skipping non-UTF8 headers
value
.to_str()
.ok()
.map(|v| (name.to_string(), v.to_string()))
})
.collect()
}
/// Convert headers from reqwest Response to axum HeaderMap
/// Filters out hop-by-hop headers that shouldn't be forwarded
pub fn preserve_response_headers(reqwest_headers: &HeaderMap) -> HeaderMap {
let mut headers = HeaderMap::new();
for (name, value) in reqwest_headers.iter() {
// Skip hop-by-hop headers that shouldn't be forwarded
let name_str = name.as_str().to_lowercase();
if should_forward_header(&name_str) {
// The original name and value are already valid, so we can just clone them
headers.insert(name.clone(), value.clone());
}
}
headers
}
/// Determine if a header should be forwarded from backend to client
fn should_forward_header(name: &str) -> bool {
// List of headers that should NOT be forwarded (hop-by-hop headers)
!matches!(
name,
"connection" |
"keep-alive" |
"proxy-authenticate" |
"proxy-authorization" |
"te" |
"trailers" |
"transfer-encoding" |
"upgrade" |
"content-encoding" | // Let axum/hyper handle encoding
"host" // Should not forward the backend's host header
)
}
/// Apply headers to a reqwest request builder, filtering out headers that shouldn't be forwarded
/// or that will be set automatically by reqwest
pub fn apply_request_headers(
headers: &HeaderMap,
mut request_builder: reqwest::RequestBuilder,
skip_content_headers: bool,
) -> reqwest::RequestBuilder {
// Always forward Authorization header first if present
if let Some(auth) = headers
.get("authorization")
.or_else(|| headers.get("Authorization"))
{
request_builder = request_builder.header("Authorization", auth.clone());
}
// Forward other headers, filtering out problematic ones
for (key, value) in headers.iter() {
let key_str = key.as_str().to_lowercase();
// Skip headers that:
// - Are set automatically by reqwest (content-type, content-length for POST/PUT)
// - We already handled (authorization)
// - Are hop-by-hop headers (connection, transfer-encoding)
// - Should not be forwarded (host)
let should_skip = key_str == "authorization" || // Already handled above
key_str == "host" ||
key_str == "connection" ||
key_str == "transfer-encoding" ||
key_str == "keep-alive" ||
key_str == "te" ||
key_str == "trailers" ||
key_str == "accept-encoding" ||
key_str == "upgrade" ||
(skip_content_headers && (key_str == "content-type" || key_str == "content-length"));
if !should_skip {
request_builder = request_builder.header(key.clone(), value.clone());
}
}
request_builder
}