Support loading weights from remote instance (#8215)

Signed-off-by: Anqi Shen <amy.saq@antgroup.com>
Co-authored-by: Chayenne <74843776+zhaochenyang20@users.noreply.github.com>

python/sglang/srt/utils.py

@@ -15,6 +15,7 @@
 
 from __future__ import annotations
 
+import argparse
 import asyncio
 import builtins
 import ctypes
@@ -1431,6 +1432,7 @@ def init_custom_process_group(
     store=None,
     group_name=None,
     pg_options=None,
+    device_id=None,
 ):
     from torch.distributed.distributed_c10d import (
         Backend,
@@ -1484,6 +1486,7 @@ def init_custom_process_group(
         group_name=group_name,
         **{pg_options_param_name: pg_options},
         timeout=timeout,
+        device_id=device_id,
     )
 
     _world.pg_group_ranks[pg] = {i: i for i in range(world_size)}
@@ -3046,3 +3049,12 @@ def numa_bind_to_node(node: int):
 
     libnuma.numa_run_on_node(ctypes.c_int(node))
     libnuma.numa_set_localalloc()
+
+
+def json_list_type(value):
+    try:
+        return json.loads(value)
+    except json.JSONDecodeError:
+        raise argparse.ArgumentTypeError(
+            f"Invalid JSON list: {value}. Please provide a valid JSON list."
+        )