From 29061ed9df84f1298806b2fc525ce4bc7eba1d29 Mon Sep 17 00:00:00 2001
From: Flex Wang <flex.wang@snowflake.com>
Date: Tue, 22 Oct 2024 20:17:28 -0700
Subject: [PATCH] [Misc] Add an env var VLLM_LOGGING_PREFIX, if set, it will be
 prepend to all logging messages (#9590)

---
 vllm/envs.py   | 5 +++++
 vllm/logger.py | 4 +++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/vllm/envs.py b/vllm/envs.py
index a2027122..ae6825f2 100644
--- a/vllm/envs.py
+++ b/vllm/envs.py
@@ -27,6 +27,7 @@ if TYPE_CHECKING:
     VLLM_USAGE_SOURCE: str = ""
     VLLM_CONFIGURE_LOGGING: int = 1
     VLLM_LOGGING_LEVEL: str = "INFO"
+    VLLM_LOGGING_PREFIX: str = ""
     VLLM_LOGGING_CONFIG_PATH: Optional[str] = None
     VLLM_TRACE_FUNCTION: int = 0
     VLLM_ATTENTION_BACKEND: Optional[str] = None
@@ -268,6 +269,10 @@ environment_variables: Dict[str, Callable[[], Any]] = {
     "VLLM_LOGGING_LEVEL":
     lambda: os.getenv("VLLM_LOGGING_LEVEL", "INFO"),
 
+    # if set, VLLM_LOGGING_PREFIX will be prepended to all log messages
+    "VLLM_LOGGING_PREFIX":
+    lambda: os.getenv("VLLM_LOGGING_PREFIX", ""),
+
     # Trace function calls
     # If set to 1, vllm will trace function calls
     # Useful for debugging
diff --git a/vllm/logger.py b/vllm/logger.py
index 77dddbfb..ccf09691 100644
--- a/vllm/logger.py
+++ b/vllm/logger.py
@@ -15,8 +15,10 @@ import vllm.envs as envs
 VLLM_CONFIGURE_LOGGING = envs.VLLM_CONFIGURE_LOGGING
 VLLM_LOGGING_CONFIG_PATH = envs.VLLM_LOGGING_CONFIG_PATH
 VLLM_LOGGING_LEVEL = envs.VLLM_LOGGING_LEVEL
+VLLM_LOGGING_PREFIX = envs.VLLM_LOGGING_PREFIX
 
-_FORMAT = "%(levelname)s %(asctime)s %(filename)s:%(lineno)d] %(message)s"
+_FORMAT = (f"{VLLM_LOGGING_PREFIX}%(levelname)s %(asctime)s "
+           "%(filename)s:%(lineno)d] %(message)s")
 _DATE_FORMAT = "%m-%d %H:%M:%S"
 
 DEFAULT_LOGGING_CONFIG = {