[bug fix] use npu phy id in container env (#14266)

Co-authored-by: jinke15 <jinke15@jd.com>

docs/advanced_features/pd_disaggregation.md

@@ -276,6 +276,10 @@ Use mooncake backend, more details can be found in mooncake section.
 ```bash
 export ENABLE_ASCEND_TRANSFER_WITH_MOONCAKE=true
 ```
+ASCEND_NPU_PHY_ID need to be set in container env
+```bash
+export ASCEND_NPU_PHY_ID=xxx
+```
 
 
 ### Llama Single Node

python/sglang/srt/disaggregation/mooncake/transfer_engine.py

@@ -3,7 +3,8 @@ import logging
 import os
 from typing import List, Optional
 
-from sglang.srt.utils import get_bool_env_var, get_free_port, maybe_wrap_ipv6_address
+from sglang.srt.environ import envs
+from sglang.srt.utils import get_free_port, maybe_wrap_ipv6_address
 
 logger = logging.getLogger(__name__)
 
@@ -164,8 +165,12 @@ class MooncakeTransferEngine:
         device_name: Optional[str],
     ) -> None:
         """Initialize the mooncake instance."""
-        if get_bool_env_var("ENABLE_ASCEND_TRANSFER_WITH_MOONCAKE", "false"):
+        if envs.ENABLE_ASCEND_TRANSFER_WITH_MOONCAKE.get():
+            npu_phy_id = envs.ASCEND_NPU_PHY_ID.get()
+            if npu_phy_id == -1:
                 hostname += f":{get_free_port()}:npu_{self.gpu_id}"
+            else:
+                hostname += f":{get_free_port()}:npu_{npu_phy_id}"
             ret_value = self.engine.initialize(
                 hostname,
                 "P2PHANDSHAKE",

python/sglang/srt/environ.py

@@ -214,6 +214,7 @@ class Envs:
     # Mooncake KV Transfer
     SGLANG_MOONCAKE_CUSTOM_MEM_POOL = EnvStr(None)
     ENABLE_ASCEND_TRANSFER_WITH_MOONCAKE = EnvBool(False)
+    ASCEND_NPU_PHY_ID = EnvInt(-1)
 
     # Mooncake Store
     SGLANG_HICACHE_MOONCAKE_CONFIG_PATH = EnvStr(None)