[Core] Allow IPv6 in VLLM_HOST_IP with zmq (#8575)

Signed-off-by: Russell Bryant <rbryant@redhat.com>

vllm/distributed/device_communicators/shm_broadcast.py

@@ -9,11 +9,12 @@ from unittest.mock import patch
 import torch
 import torch.distributed as dist
 from torch.distributed import ProcessGroup
+from zmq import IPV6  # type: ignore
 from zmq import SUB, SUBSCRIBE, XPUB, XPUB_VERBOSE, Context  # type: ignore
 
 import vllm.envs as envs
 from vllm.logger import init_logger
-from vllm.utils import get_ip, get_open_port
+from vllm.utils import get_ip, get_open_port, is_valid_ipv6_address
 
 VLLM_RINGBUFFER_WARNING_INTERVAL = envs.VLLM_RINGBUFFER_WARNING_INTERVAL
 
@@ -214,6 +215,8 @@ class MessageQueue:
             self.remote_socket = context.socket(XPUB)
             self.remote_socket.setsockopt(XPUB_VERBOSE, True)
             remote_subscribe_port = get_open_port()
+            if is_valid_ipv6_address(connect_ip):
+                self.remote_socket.setsockopt(IPV6, 1)
             socket_addr = f"tcp://*:{remote_subscribe_port}"
             self.remote_socket.bind(socket_addr)
 
@@ -274,6 +277,8 @@ class MessageQueue:
 
             self.remote_socket = context.socket(SUB)
             self.remote_socket.setsockopt_string(SUBSCRIBE, "")
+            if is_valid_ipv6_address(handle.connect_ip):
+                self.remote_socket.setsockopt(IPV6, 1)
             socket_addr = f"tcp://{handle.connect_ip}:{handle.remote_subscribe_port}"
             logger.debug("Connecting to %s", socket_addr)
             self.remote_socket.connect(socket_addr)

vllm/utils.py

@@ -5,6 +5,7 @@ import datetime
 import enum
 import gc
 import inspect
+import ipaddress
 import os
 import random
 import socket
@@ -533,6 +534,14 @@ def get_ip() -> str:
     return "0.0.0.0"
 
 
+def is_valid_ipv6_address(address: str) -> bool:
+    try:
+        ipaddress.IPv6Address(address)
+        return True
+    except ValueError:
+        return False
+
+
 def get_distributed_init_method(ip: str, port: int) -> str:
     # Brackets are not permitted in ipv4 addresses,
     # see https://github.com/python/cpython/issues/103848