Files
2026-01-19 10:38:50 +08:00

46 lines
1.5 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
import prometheus_client
import regex as re
from fastapi import FastAPI, Response
from prometheus_client import make_asgi_app
from prometheus_fastapi_instrumentator import Instrumentator
from starlette.routing import Mount
from vllm.v1.metrics.prometheus import get_prometheus_registry
class PrometheusResponse(Response):
media_type = prometheus_client.CONTENT_TYPE_LATEST
def attach_router(app: FastAPI):
"""Mount prometheus metrics to a FastAPI app."""
registry = get_prometheus_registry()
# `response_class=PrometheusResponse` is needed to return an HTTP response
# with header "Content-Type: text/plain; version=0.0.4; charset=utf-8"
# instead of the default "application/json" which is incorrect.
# See https://github.com/trallnag/prometheus-fastapi-instrumentator/issues/163#issue-1296092364
Instrumentator(
excluded_handlers=[
"/metrics",
"/health",
"/load",
"/ping",
"/version",
"/server_info",
],
registry=registry,
).add().instrument(app).expose(app, response_class=PrometheusResponse)
# Add prometheus asgi middleware to route /metrics requests
metrics_route = Mount("/metrics", make_asgi_app(registry=registry))
# Workaround for 307 Redirect for /metrics
metrics_route.path_regex = re.compile("^/metrics(?P<path>.*)$")
app.routes.append(metrics_route)