feat - add validation for existing customers

litellm/proxy/proxy_server.py

@@ -7833,12 +7833,14 @@ async def new_end_user(
             status_code=500,
             detail={"error": CommonProxyErrors.db_not_connected_error.value},
         )
+    try:
 
         ## VALIDATION ##
         if data.default_model is not None:
             if llm_router is None:
                 raise HTTPException(
-                status_code=422, detail={"error": CommonProxyErrors.no_llm_router.value}
+                    status_code=422,
+                    detail={"error": CommonProxyErrors.no_llm_router.value},
                 )
             elif data.default_model not in llm_router.get_model_names():
                 raise HTTPException(
@@ -7878,6 +7880,30 @@ async def new_end_user(
         )
 
         return end_user_record
+    except Exception as e:
+        if "Unique constraint failed on the fields: (`user_id`)" in str(e):
+            raise ProxyException(
+                message=f"Customer already exists, passed user_id={data.user_id}. Please pass a new user_id.",
+                type="bad_request",
+                code=400,
+                param="user_id",
+            )
+
+        if isinstance(e, HTTPException):
+            raise ProxyException(
+                message=getattr(e, "detail", f"Internal Server Error({str(e)})"),
+                type="internal_error",
+                param=getattr(e, "param", "None"),
+                code=getattr(e, "status_code", status.HTTP_500_INTERNAL_SERVER_ERROR),
+            )
+        elif isinstance(e, ProxyException):
+            raise e
+        raise ProxyException(
+            message="Internal Server Error, " + str(e),
+            type="internal_error",
+            param=getattr(e, "param", "None"),
+            code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+        )
 
 
 @router.get(