refac: pass through ollama error message

backend/open_webui/routers/ollama.py

@@ -147,8 +147,23 @@ async def send_post_request(
             },
             ssl=AIOHTTP_CLIENT_SESSION_SSL,
         )
-        r.raise_for_status()
 
+        if r.ok is False:
+            try:
+                res = await r.json()
+                if "error" in res:
+                    log.error(f"Error from server: {res['error']}")
+                    raise HTTPException(status_code=r.status, detail=res["error"])
+            except HTTPException as e:
+                raise e  # Re-raise HTTPException to be handled by FastAPI
+            except Exception as e:
+                log.error(f"Failed to parse error response: {e}")
+                raise HTTPException(
+                    status_code=r.status,
+                    detail=f"Open WebUI: Server Connection Error",
+                )
+
+        r.raise_for_status()  # Raises an error for bad responses (4xx, 5xx)
         if stream:
             response_headers = dict(r.headers)
 
@@ -168,20 +183,14 @@ async def send_post_request(
             await cleanup_response(r, session)
             return res
 
+    except HTTPException as e:
+        raise e  # Re-raise HTTPException to be handled by FastAPI
     except Exception as e:
-        detail = None
+        detail = f"Ollama: {e}"
-
-        if r is not None:
-            try:
-                res = await r.json()
-                if "error" in res:
-                    detail = f"Ollama: {res.get('error', 'Unknown error')}"
-            except Exception:
-                detail = f"Ollama: {e}"
 
         raise HTTPException(
             status_code=r.status if r else 500,
-            detail=detail if detail else "Open WebUI: Server Connection Error",
+            detail=detail if e else "Open WebUI: Server Connection Error",
         )