111 lines
3.3 KiB
Python
111 lines
3.3 KiB
Python
"""OpenTelemetry metrics bootstrap for Open WebUI.
|
||
|
||
This module initialises a MeterProvider that sends metrics to an OTLP
|
||
collector. The collector is responsible for exposing a Prometheus
|
||
`/metrics` endpoint – WebUI does **not** expose it directly.
|
||
|
||
Metrics collected:
|
||
|
||
* http.server.requests (counter)
|
||
* http.server.duration (histogram, milliseconds)
|
||
|
||
Attributes used: http.method, http.route, http.status_code
|
||
|
||
If you wish to add more attributes (e.g. user-agent) you can, but beware of
|
||
high-cardinality label sets.
|
||
"""
|
||
|
||
from __future__ import annotations
|
||
|
||
import time
|
||
from typing import Dict, List, Sequence, Any
|
||
|
||
from fastapi import FastAPI, Request
|
||
from opentelemetry import metrics
|
||
from opentelemetry.exporter.otlp.proto.grpc.metric_exporter import (
|
||
OTLPMetricExporter,
|
||
)
|
||
from opentelemetry.sdk.metrics import MeterProvider
|
||
from opentelemetry.sdk.metrics.view import View
|
||
from opentelemetry.sdk.metrics.export import (
|
||
PeriodicExportingMetricReader,
|
||
)
|
||
from opentelemetry.sdk.resources import SERVICE_NAME, Resource
|
||
|
||
from open_webui.env import OTEL_SERVICE_NAME, OTEL_EXPORTER_OTLP_ENDPOINT
|
||
|
||
|
||
_EXPORT_INTERVAL_MILLIS = 10_000 # 10 seconds
|
||
|
||
|
||
def _build_meter_provider() -> MeterProvider:
|
||
"""Return a configured MeterProvider."""
|
||
|
||
# Periodic reader pushes metrics over OTLP/gRPC to collector
|
||
readers: List[PeriodicExportingMetricReader] = [
|
||
PeriodicExportingMetricReader(
|
||
OTLPMetricExporter(endpoint=OTEL_EXPORTER_OTLP_ENDPOINT),
|
||
export_interval_millis=_EXPORT_INTERVAL_MILLIS,
|
||
)
|
||
]
|
||
|
||
# Optional view to limit cardinality: drop user-agent etc.
|
||
views: List[View] = [
|
||
View(
|
||
instrument_name="http.server.duration",
|
||
attribute_keys=["http.method", "http.route", "http.status_code"],
|
||
),
|
||
View(
|
||
instrument_name="http.server.requests",
|
||
attribute_keys=["http.method", "http.route", "http.status_code"],
|
||
),
|
||
]
|
||
|
||
provider = MeterProvider(
|
||
resource=Resource.create({SERVICE_NAME: OTEL_SERVICE_NAME}),
|
||
metric_readers=list(readers),
|
||
views=views,
|
||
)
|
||
return provider
|
||
|
||
|
||
def setup_metrics(app: FastAPI) -> None:
|
||
"""Attach OTel metrics middleware to *app* and initialise provider."""
|
||
|
||
metrics.set_meter_provider(_build_meter_provider())
|
||
meter = metrics.get_meter(__name__)
|
||
|
||
# Instruments
|
||
request_counter = meter.create_counter(
|
||
name="http.server.requests",
|
||
description="Total HTTP requests",
|
||
unit="1",
|
||
)
|
||
duration_histogram = meter.create_histogram(
|
||
name="http.server.duration",
|
||
description="HTTP request duration",
|
||
unit="ms",
|
||
)
|
||
|
||
# FastAPI middleware
|
||
@app.middleware("http")
|
||
async def _metrics_middleware(request: Request, call_next):
|
||
start_time = time.perf_counter()
|
||
response = await call_next(request)
|
||
elapsed_ms = (time.perf_counter() - start_time) * 1000.0
|
||
|
||
# Route template e.g. "/items/{item_id}" instead of real path.
|
||
route = request.scope.get("route")
|
||
route_path = getattr(route, "path", request.url.path)
|
||
|
||
attrs: Dict[str, str | int] = {
|
||
"http.method": request.method,
|
||
"http.route": route_path,
|
||
"http.status_code": response.status_code,
|
||
}
|
||
|
||
request_counter.add(1, attrs)
|
||
duration_histogram.record(elapsed_ms, attrs)
|
||
|
||
return response
|