From 31c23e5fe3ecb5912a47bc32775309daa77d5065 Mon Sep 17 00:00:00 2001
From: fzyzcjy <5236035+fzyzcjy@users.noreply.github.com>
Date: Sat, 13 Dec 2025 13:27:06 +0800
Subject: [PATCH] Provide more fine grained error reason for reqwest error
 (#15032)

---
 sgl-model-gateway/src/routers/error.rs       |  2 +-
 sgl-model-gateway/src/routers/http/router.rs | 63 +++++++++++++++++---
 2 files changed, 56 insertions(+), 9 deletions(-)

diff --git a/sgl-model-gateway/src/routers/error.rs b/sgl-model-gateway/src/routers/error.rs
index 035d8086a..7231c94d2 100644
--- a/sgl-model-gateway/src/routers/error.rs
+++ b/sgl-model-gateway/src/routers/error.rs
@@ -37,7 +37,7 @@ pub fn method_not_allowed(code: impl Into<String>, message: impl Into<String>) -
     create_error(StatusCode::METHOD_NOT_ALLOWED, code, message)
 }
 
-fn create_error(
+pub fn create_error(
     status: StatusCode,
     code: impl Into<String>,
     message: impl Into<String>,
diff --git a/sgl-model-gateway/src/routers/http/router.rs b/sgl-model-gateway/src/routers/http/router.rs
index 0cb028865..de1c17c83 100644
--- a/sgl-model-gateway/src/routers/http/router.rs
+++ b/sgl-model-gateway/src/routers/http/router.rs
@@ -112,9 +112,7 @@ impl Router {
                             ),
                         }
                     }
-                    Err(e) => {
-                        error::internal_error("request_failed", format!("Request failed: {}", e))
-                    }
+                    Err(e) => convert_reqwest_error(e),
                 }
             }
             Err(e) => error::service_unavailable("no_workers", e),
@@ -363,10 +361,7 @@ impl Router {
                     }
                 }
                 Err(e) => {
-                    last_response = Some(error::internal_error(
-                        "request_failed",
-                        format!("Request failed: {}", e),
-                    ));
+                    last_response = Some(convert_reqwest_error(e));
                 }
             }
         }
@@ -506,7 +501,7 @@ impl Router {
                     }
                 }
 
-                return error::internal_error("request_failed", format!("Request failed: {}", e));
+                return convert_reqwest_error(e);
             }
         };
 
@@ -666,6 +661,58 @@ fn decrement_load(w: &Arc<dyn Worker>) {
     RouterMetrics::set_running_requests(w.url(), w.load());
 }
 
+fn convert_reqwest_error(e: reqwest::Error) -> Response {
+    let url = e
+        .url()
+        .map(|u| u.to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+    let message = format!("{}. URL: {}", e, url);
+
+    // TODO improve error status code
+    let (status, code) = if let Some(upstream_status) = e.status() {
+        (upstream_status, "call_upstream_status_error")
+    } else if e.is_builder() {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "call_upstream_builder_error",
+        )
+    } else if e.is_request() {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "call_upstream_request_error",
+        )
+    } else if e.is_redirect() {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "call_upstream_redirect_error",
+        )
+    } else if e.is_body() {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "call_upstream_body_error",
+        )
+    } else if e.is_decode() {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "call_upstream_decode_error",
+        )
+    } else if e.is_timeout() {
+        (StatusCode::INTERNAL_SERVER_ERROR, "call_upstream_timeout")
+    } else if e.is_connect() {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "call_upstream_connection_failed",
+        )
+    } else {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "call_upstream_request_failed",
+        )
+    };
+
+    error::create_error(status, code, message)
+}
+
 use async_trait::async_trait;
 
 #[async_trait]