4 files changed, 30 insertions, 15 deletions
diff --git a/pingora-proxy/examples/gateway.rs b/pingora-proxy/examples/gateway.rs
index 78f4aae..d4a5cee 100644
--- a/pingora-proxy/examples/gateway.rs
+++ b/pingora-proxy/examples/gateway.rs
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 use async_trait::async_trait;
+use bytes::Bytes;
 use clap::Parser;
 use log::info;
 use prometheus::register_int_counter;
@@ -42,7 +43,9 @@ impl ProxyHttp for MyGateway {
         if session.req_header().uri.path().starts_with("/login")
             && !check_login(session.req_header())
         {
-            let _ = session.respond_error(403).await;
+            let _ = session
+                .respond_error_with_body(403, Bytes::from_static(b"no way!"))
+                .await;
             // true: early return as the response is already written
             return Ok(true);
         }
@@ -103,7 +106,7 @@ impl ProxyHttp for MyGateway {
     }
 }
 
-// RUST_LOG=INFO cargo run --example load_balancer
+// RUST_LOG=INFO cargo run --example gateway
 // curl 127.0.0.1:6191 -H "Host: one.one.one.one"
 // curl 127.0.0.1:6190/family/ -H "Host: one.one.one.one"
 // curl 127.0.0.1:6191/login/ -H "Host: one.one.one.one" -I -H "Authorization: password"
diff --git a/pingora-proxy/src/lib.rs b/pingora-proxy/src/lib.rs
index 731cdb4..fa639f2 100644
--- a/pingora-proxy/src/lib.rs
+++ b/pingora-proxy/src/lib.rs
@@ -143,9 +143,14 @@ impl<SV> HttpProxy<SV> {
             }
             Err(mut e) => {
                 e.as_down();
-                error!("Fail to proxy: {}", e);
+                error!("Fail to proxy: {e}");
                 if matches!(e.etype, InvalidHTTPHeader) {
-                    downstream_session.respond_error(400).await;
+                    downstream_session
+                        .respond_error(400)
+                        .await
+                        .unwrap_or_else(|e| {
+                            error!("failed to send error response to downstream: {e}");
+                        });
                 } // otherwise the connection must be broken, no need to send anything
                 downstream_session.shutdown().await;
                 return None;
@@ -344,16 +349,16 @@ impl Session {
         &self.downstream_session
     }
 
-    /// Write HTTP response with the given error code to the downstream
+    /// Write HTTP response with the given error code to the downstream.
     pub async fn respond_error(&mut self, error: u16) -> Result<()> {
-        let resp = HttpSession::generate_error(error);
-        self.write_response_header(Box::new(resp), true)
+        self.as_downstream_mut().respond_error(error).await
+    }
+
+    /// Write HTTP response with the given error code to the downstream with a body.
+    pub async fn respond_error_with_body(&mut self, error: u16, body: Bytes) -> Result<()> {
+        self.as_downstream_mut()
+            .respond_error_with_body(error, body)
             .await
-            .unwrap_or_else(|e| {
-                self.downstream_session.set_keepalive(None);
-                error!("failed to send error response to downstream: {e}");
-            });
-        Ok(())
     }
 
     /// Write the given HTTP response header to the downstream
diff --git a/pingora-proxy/src/proxy_cache.rs b/pingora-proxy/src/proxy_cache.rs
index 8957bc7..c720575 100644
--- a/pingora-proxy/src/proxy_cache.rs
+++ b/pingora-proxy/src/proxy_cache.rs
@@ -295,7 +295,13 @@ impl<SV> HttpProxy<SV> {
             }
             Err(e) => {
                 // TODO: more logging and error handling
-                session.as_mut().respond_error(500).await;
+                session
+                    .as_mut()
+                    .respond_error(500)
+                    .await
+                    .unwrap_or_else(|e| {
+                        error!("failed to send error response to downstream: {e}");
+                    });
                 // we have not write anything dirty to downstream, it is still reusable
                 return (true, Some(e));
             }
diff --git a/pingora-proxy/src/proxy_trait.rs b/pingora-proxy/src/proxy_trait.rs
index 4017789..6970ec0 100644
--- a/pingora-proxy/src/proxy_trait.rs
+++ b/pingora-proxy/src/proxy_trait.rs
@@ -372,7 +372,6 @@ pub trait ProxyHttp {
     where
         Self::CTX: Send + Sync,
     {
-        let server_session = session.as_mut();
         let code = match e.etype() {
             HTTPStatus(code) => *code,
             _ => {
@@ -392,7 +391,9 @@ pub trait ProxyHttp {
             }
         };
         if code > 0 {
-            server_session.respond_error(code).await
+            session.respond_error(code).await.unwrap_or_else(|e| {
+                error!("failed to send error response to downstream: {e}");
+            });
         }
         code
     }